JET ENGINE 1. Duplex ball bearings takes a) axial and radial axis efficiently b) axial load only c) fail safe loading 2. The fig shows a modern turbofan engine, the purpose at the vertex device is a) to dissipate the heat from the fan cowl b) to streamline the airflow over the wing surface c) to reduce the turbulance of airflow over the wind during low speeds of flight d) to reduce the turbulance of airflow over the wind during high speeds of flight 3. A modern turbotantengine fitted a/c flying from Delhi to Madras. The temperature at Delhi is 15°C, while in Madrasis 28°C. to achieve the same power at Madras. a) throttle should be adjusted fwd when approaching at Madras b) throttle should be retarded when approaching madras c) no adjustment is necessary throughout the flight d) throttle can be adjusted either fwd or retarded to keep the Ni rpm constant 4. Match the following: a) X-40 steel b) Rene 84 Co c) 6-2-42 Ni d) A286 Ti 5. Fig. a) pressure is high in tube A b) pressure is high in tube B c) pressure is same through d) there will be rise in pressure in tube B due to turbulance 6. In flight CSD oil temp light comes ‘ON’ and the pilot disconnected the CSD. Then it can be connected back a) only on ground b) only in flight c) either on ground or in flight 1
d) automatically connected after oil temp is reduced 7. Starter has two holes, for a) alignment b) breather sump vent 8. For the same torque, starter is heavier than starter generator, a) starter generator has two separate windings 9. In Bryton Cycie DE shows…Fig a) Expansion thru’ nozzle 10. Ni-metalic sensing is fitted on a) pressure regulating valve b) FCOC (fuel control oil cooler) c) Min flow valve 11. A) In FCU, variation in temperatures is compensated by Bi-mettalic disc (or) 12. If the metal found in the chip detector gives white light while burning, it confirms the presence of a) steel b) Mg c) Cr 13. Exhaust nozzle area is changed due to heat after long operation, it will cause a) the thrust to reduce for the amount of fuel flow b) the thrust will increase with the increase in EGT c) no appriciable change in thrust or EGT as the area is same for that temperature d) the thrust will increase due to increase of fuel flow due to more airflow through inlet 14. CODEP means a) cobalt coating b) coating given to LPT blades c) coating given to improve the corrosion resistance in elevated temp of turbine blades d) fuel additive 15. Mark the correct statement a) compressors are loaded in front stages b) compressors are loaded more at rear stages 2
c) compressor are equally loaded 16. Kevlar is used in fan casing fabrication. Al foil presence in kevlar a) prevent stress b) acts as a lightening arrester c) used in light frequency operation 17. BSI of HPT is done thorough the holes given. During insp the HPT shaft is rotated by a) remove starter and rotate through the starter engagement gears b) drive pad is given for this purpose in the AGB section of these engines c) after removing the combustion chamber only, BSI can be done d) 7/8” socket and spanner attached in the hand cracking pad 18. During water methanol injection at which place will increase the temperature a) compressor inlet b) diffuser c) compressor and diffuser 19. Pressurising valve setting at low spring tension causes (or) adjustment of P&D valve on FCU is lower than the normal then.. a) hot start b) hung start 20. Fog. Of Thrust reverser…identify the component a) blocker door b) drag plate c) T/R unlock pop-out indicator 21. Fig… Identify the bolt used in Hot Section a) A is used in hot section b) B is used in hot section c) B or C are used in hot section d) None of the above 22. Fig. Impeller tip speed of centrifugal compressor limits the performance of the compressor, this is because.. a) tip speed reaching mach no b) excessive compression 23. Fig. Of Magnetic sea a) A is magnetic ring b) B is magnetic ring 3
c) C is magnetic ring 24. Mark the correct statement regarding usage of the Helical gears used in Turbo Prop gear box a) helical gears are easy to manufacture and economical b) helical gears takes more loads because they are straight 25. Dilution of air/fucl mix takes place in a) inner swril vanes b) outer swril vanes 26. If electronic control box is not fitted on APU, then.. a) load control valve can be adjusted after shutdown of APU b) surge bleed valve operates on when no load control valve 27. APU event marker indicates a) No of APU shutdown b) No of APU starts c) Over temperature d) Starting including hung start 28. The purpose of feedback cable used in Thrust Reverser is a) to prevent fwd thrust selection, if they are in deployed condition b) to bring back the thrust lever to idle in case, the doors move opposition to selection in either fwd or reverse c) both a & b are correct 29. In Hyd. Mechanical Torquemeter torque is senced and transmitted by 30. FCU M.S.B.V. (?) high pressure symbol causes…? 31. For subsonic jet the inlet must have… 32. Fire extinguisher test provides… 33. Compressor fitted with layer turbot in… 34. Compressor blade dia… 35. Thermal efficiency of piston engine is higher than the jet engine is due to… 36. JPT crosses limits due to 37. Inlet of the hyd pump is blocked, then… 4
38. Efficient combustion cooling is… 39. Trimmer resister on EGT indication system ensures a) a constant resistance value b) increase / decrease in resistance c) adjust BPT as per requirements 40. In turbo shaft engine above 400 knots of speed increases (25000 ft altitude??) a) before sonic compression is low b) compress ratio increases above sonic velocity 41. Back up to NTS a) TSS b) Prop brake c) Safety coupling 42. Fig. Identify the component a) Fuel pump b) Oil pump 43. Fig. Identify the correct cockpit indication diagram. 44. Fig. Find out the stall angle… 45. Match the following: a) torque cam Turbine rotor b) torque hange compressor c) snoub turbine stator d) lock taps combustion chamber 46. After the engine tight up, starter did not cuts off. The probable cause will be a) starter cut off circuit is faulty b) starter drive spring is weak c) starter bleed valve did not close d) either a or b is correct 47. Rotary air-oil separator is used in a) MGB to drain the oil pack sump b) AGB to drain the oil back to sump c) Bearing sump to remove air from the oil drained d) Located in the MGB near the vent outlet, throws the oil outward to drain back in to the sump and allow pressurizing air. 5
48. Hot shift and cold shift of modern engine is determined by a) CIT sensor probe condition b) TIT sensor probe condition c) Throttle lever angle and its position in conjunction with MEC d) ITI sensor and CIT sensor condition. 49. Engine anti-icing system consists of ducting and a) heats up fwd and rearward simultaneously b) heats up fwd and rearward in cyclic operation c) consists of dual butterfly valve, which regulates the hot bleed air in relation with a timer circuit. d) Can be used both flight and ground operation. 50. LOP fight illuminated during flight. What are the other parameters in connection with it, the pilot has to check inside the cockpit indicators. a) EGT and RPM indicator for the engine malfunctions. b) Ni rpm gauge and oil temperature gauge. c) Filter clogging light and EGT d) No indicator to check, but to cut off the engine 51. Igniter, plugs should not be touched with bare hand because a) high radioactive material are used and it will cause radiation through the body b) tips are made up of tungsten carbide and it will get damaged
6
JET ENGINE 1. Blade is an angle formed by a line perpendicular to the propeller shaft and line formed by the (a) Relative wind (b) Apparent wind (c) Chord of the blade (d) Blade face 2. Thrust produced by a rotating propeller is a result of (a) Propeller slippage (b) An area of low pressure behind the propeller (c) An area of decreased pressure immediately in front of the pressure blades (d) The angle of relative wind and rotational velocity wind and rotational velocity of the propeller 3. Propeller blade station number increase from (a) Huh to tip (b) Tip to hule (c) Leading edge to aft edge (d) Aft edge of leading edge 4. It should have high specific gravity (a) Low pan point 5. Velocity index should be high. High freezing point – at a cold atm the water contents in the fuel in having tendency to form in a ice crystal 6. It should be filtered to jet engine (a) It should have low carbon content after burning the fuel 7. In twin spool engine, with constant N2, compressor inlet temperature is decreasing then (a) N2 changes (b) Fuel flow increases (c) N1 decreases (d) The ratio N1 is maintained constant N2 8. The thrust developed by high bypass ratio engine is (a) Indicated by EGT (b) Indicated by N2 (c) Proportional fan speed (d) Not affected by ambient conditions 7
9. Perceived noise decibel (PNDB) level is low in case of (a) Pure jets without noise suppressor (b) Straight jet with noise suppressor (c) Low by pass jets (d) High by pass jets with acoustic panel 10. Ignitor plug spark is due to (a) High frequency (b) High input current (c) Discharge (storage) capacitor (d) DC voltage 11. In a ‘hot tank’ oil system (a) Oil cooler is not provided (b) Oil is stored in a separate tank (c) Oil is at high temp in the tank (d) De-aerator effect is very slow 12. If jet velocity and mass flow is constant for a jet engine then thrust (a) Is maximum when aircraft speed is minimum (b) Is maximum when aircraft speed is maximum (c) Is more when jet velocity and inlet velocity are equal (d) Is always constant 13. Water injection systems are provides for the jet engine for the thrust augmentation the thrust augmentation for water injection can be caused and by two methods. (a) By adding or injecting water at the compressor inlet (b) By adding or injecting water at the differ section Fig shown that a water tank made up of aluminum or sheet metal allows the water flow a regulating It then panes to the pressure regulating V/o of the diffuse and compressor inlet thought which water injection in done by providing two manifolds at the diffuse and compressor manifold. A water heater is provided for the water to not formed ice in cold atm or cold weather condition A drain a/v provided to drain full water tank after are it is generally use of after getting sufficient thrust by water injection Water injection system used when aircraft an going to take off 8
14. In a compressor space between surge line and working lines called (a) Safety margin on surge margin (b) Stable zone unstable zone (c) Unstable zone (d) Stagger zone 15. Hottest zone in turbine engine is (a) Compressor outlet (b) Turbine (c) 1st stage NGV (d) Exhaust nozzle 16. In a high by pass engine NGV’s are eliminated (a) To reduced noise (b) To reduce weight (c) To increase efficiency (d) To satisfy 1 and 2 above For maximum thrust The thrust augmentation is achieved a the compressor inlet by injecting water at the compressor inlet which increases mass airflow and their by thrust Thrust augmentation is achieved a the diffuser section by injecting water at the diffuser section and which als the diffuser section and decreases the temperature of the diffuser section which gives high deme man airflow high affect to maximum 17. Brayton cycle is (a) Constant temperature cycle (b) Constant volume cycle (c) Constant pressure and constant temperature cycle 18. NGV’s of turbine are usually (a) Hollow (b) Solid (c) Air cooled (d) As per (1) & (2) above 19. Most common defects in combustion chamber is (a) Crack and burning (b) Scoring (c) Pitting (d) Blistering 9
20. Jet engine ignition system. Jet engine ignition system is a high intensity and dual capacitor discharge type are used The two system are used for the ignition system (a) Low voltage A.C or D.C type ignition system (b) High voltage capacitor discharge type ignition system 21. High voltage capacitor discharge type ignition system FIGURE SHOWN HIGH VOLTAGE CAPACITOR DISHCARGE TYPE CUT (A.G) A 115 A.C is provided bu E.S.I. but to the primary coil of the transformer A to reduce the noise level a filter cut is provided at the primary After paning 115V at the primary a seen way coil induces a voltage of about 2000V approximately which paner through solid rectifier A through resistance to the dual capacitor or storage capacitor which store the electrically charger In the next cycle a 20000 is paned through rectifier B this resistance 22. Combustion chamber used in a modern jet engines are (a) Can annular type (b) Annular type (c) Can type (d) As stated in 1 and 2 23. Exhaust nozzle is (a) No necessary for jet engines (b) Made up of titanium alloy (c) Made up of aluminum alloy (d) A must for jet engine 24. Internal energy of a perfect gas is (a) A function of temperature only (b) A function of pressure only (c) Always constant (d) A function of temperature and pressure 25. The turbo jet engines (a) Can be used in thermal power stations as prime stations as primer movers (b) Are more efficient at lower altitudes (c) Work on Newton’s third law of motion (d) (2) and (3) above are correct 10
26. Compression process in axial compressor is (a) Isothermal (b) Adiabatic (c) Isobaric (d) Isometric 27. Compressor pressure ratio of an engine compressor depends upon (a) Ambient pressure (b) Ambient temperature and ambient pressure (c) Speed and ambient pressure (d) Speed mass airflow and ambient temperature The energy stored in a dual capacitor and storage charger at a fule charge level and then tenses the tube this caused charger when fully developed it induces in the primary winding of the transformer (TRIGGER), which is of up to app 2000 V This induces a appx of 20,000V to the secondary of the tram former winding and which gives high intensity current flow thr ignite plug which gives spark A bleeder resistance are provided for troiger capacitor to give protection for excess voltage Two igniter plug are used for capacitor discharge type cht for alternate operations 28. The fuel nozzles used in modern gas turbine engines (a) Are always of dual type (b) Are identical for engine with same power rating (c) Are welded to the combustion chamber (d) Is the last component in the fuel system 29. Anti – icing system used on jet aircrafts (a) Is fully automatic (b) Is to be used only to melt the ice formed (c) Never makes use of electrical heaters (d) Need not be used thought the flight 30. How many igniters are usually used on a turbine engine having nine burner cans? (a) One (b) Two (c) Three (d) Nine 31. The material used for jet engine is following main fine types 11
(a) Titanium (b) Aluminum or Aluminum alloy (c) Nickel bare alloy (d) Nickel chrome alloy (e) Steel or stainless steel Titanium are high resistant to 1000 & corrosion and are used for fan blades and sometime for compressor vanes Aluminum or aluminum alloy are used for jet engine for its light weight characteristics it is high resistant to corrosion heat Nickel- chrome alloy’s re used fore turbine blades, which stands for high temperature Steel or stainless steel alloy are used for rota vane or staten vane in an axial flow type jet 32. In an axial flow turbine engine, compressor bled air is sometimes used to aid in the cooling of (a) Oil (b) IGV (c) Fuel cooler (d) Turbine 33. Which of the following turbine fuel filters has the greatest filtering action? (a) Micron (b) Wire mesh (c) Wafer screen (d) Stacked charcoal 34. For starting a turbine engine (a) D.C motor is never used (b) Very very low cranking speeds are required (c) Ignition is necessary (d) Statements 2 and 3 are correct 35. Mechanical integrity of the turbine as well as engine operating conditions of the engine can be checked by (a) Engine oil pressure (b) Exhaust gas temperature (c) Engine oil temperature (d) Engine pressure ratio 12
36. Which parameter will determine engine power? (a) EGT and vibration meter (b) RPM and oil pressure (c) RPM and fuel pressure (d) EPR OR RPM 37. Mark the correct statement (a) Thrust reverse reduces landing roll (b) Oil pressure for jet engine is always regulated (c) VSV’ are not provided on modern jet engine (d) By providing fire wall in the engine cowl compartment engine fire detection element can be eliminated
13
JET ENGINE JUNE – 2002 1. EGT measuring thermocouples are connected in (a) Series (b) Parallel (c) Series parallel 2. Angle of attack of a propeller is (a) Angle between chord line and plane of rotations (b) Angle between chord line and relative wind direction (c) Angle between chord line and longitudinal axis the aircraft 3. Mark the correct statement (a) Geometric pitch is the distance traveled by propeller in one rotations (b) Effective pitch is the actual distance traveled by the propeller in on rotations (c) Slip is the difference between geometric pitch and effective pitch (d)All of the above 4. Mark the correct statement regarding propeller tracking (a) Propeller tracking is determining tip position relative to others propeller (b) Static balancing of propeller (c) Dynamic balancing of propeller (d) All of the above 5. Mark the correct statement (a) In alpha range blade angle is controlled by governor 6. Compressor blades are attached with disc (a) Dove tail (b) Fir tree with various locking (c) as above (a) & (b) 7. Reduced cooling air requirements by 50 percent and decreased wt. By 20% is in which system (a) Air film cooling (b) Transpiration cooling (c) Impingement cooling (d)Fin wall 8. Mark correct statement regarding gas turbine igniter (a) Gap is more engine to reciprocating because operating provision 14
(b) As (a) and less fouling problem (c) As (b) and high energy (d)As (c) and Condition lever (propeller lever) controls – free power turbine (NF) Power lever (Throttle) controls - FCU & has generator turbine (N8) If instruction indicating high / rise then compressor combination If instruction indicating low / decrease then turbine de effectors 9. Shrouding of turbine blades (a) Reduces tip loss (b) As (a) prevent excessive vibration (c) As (b) and prevent twisting (d)As (c) and operate cool as extra mass in tip at reduced speed 10. Mark correct statement (a) Thrust reverse is used in the fan discharge (b) 50% reverse thrust provided 35 to 50% (c) Core engine exhaust is used for forward thrust (d)All the above 11. Wet thrust rating is (a) Water injection is on (b) Cooling period of engine (c) Water injection off (d) Diffuser 12. Water is injected in compressor inlet and difficult then (a) Surge line shifts down (b)Surge line shifts away 13. Speed droop is common to all mechanical governors to reduce these problems (a) Use a weaker spring (b) Make metering valve narrow radically (c) Decrease pressure difference across metering valve (d) All of the above 14. Mark the correct statement (a) Paper cartage type filter used in low preside (b) As 1 and screen disc type filter used I hi pr side (c) As 2 and (d)All of the above 15. for lubrication 15
(a) High viscosity index oil is required
(b) Hi acidity oil is used (c) Hi pour point oil is used (d) All of the above 16. Mark the correct and statement (a) Scavenger pump is centrifugal type of the larger capacity (b) Pr pump is centrifugal type (c) Scavenger pump capacity is smaller than Pr. Pump (d)Both pump are gear type 17. Pressure relief valve pr I equipped with centrifugal boast arrangement (a) Boost pump pressure (b)Main pump pr (c) Filter pr (d) All of the above 18. In starter generator (a) Two field winding are used (b) One common armature is used (c) Starter is used for starting of generator for electrical power (d)All of the above 19. In gas turbine engine (a) Starter is disconnected as soon as light off (b) Starter is on to give specified speed to engine 20. In performance monitor ring all parameter are in increasing order then it shows failure (a) Turbine (b)Compressor (c) Combustion (d) In let guide valve 21. During starting fire, fire extinguisher is discharge (a) Engine is cleaned (b) Engine replaced and sent to shape 22. Blending is done to (a) Reencountering the blade 23. For the maintenance purpose engine is dividing in the two sections, in hot section (a) Turbine combustion exhaust nozzle (b) Turbine, diffuser, exhaust nozzle 16
(c) HP compressor, combustion, exhaust nozzle (d) HP compressor, combustion, turbine 24. FCU senses (a) Rpm (b) As I and CDP (c) As 2 and EDP (d) AS 3 and 1 25. In helicopter which engine is used (a) Turbo shaft (b) Turbo fan (c) Free power turbine (N1) (d) Above 1 & 3 26. Advantage of centrifugal compressor (a) Hi pr ratio per stage 27. In convergent nozzle used in supersonic speed (a) Pr. Increased volume decreased (b) Velocity increased 28. Bleeding check (a) Bleed valve closed (b) Bleed valve open (c) Variable stator vane close 29. TSFC is (a) Directly proportional to compression ration (b)Indirectly 30. Mark correct statement (a) Thrust due to pr fall is more than thrust increase due to temperature fall 31. Mark correct statement (a) Most compression engines using annular combustion chamber (b) Can – annular is best efficient 32. Which one is fuel flow rate indicator without motor (a) Vane type (b) Impeller – turbine type 33. Mark the correct statement (a) Red radial line is maximum permissible range 17
34. In two wire thermal switch fire detecting (a) Open circuit will give indication 35. In modern vibration indication system (a) It consists of pick – up, signal conditional indicator (b) Later – piezoelectric – acceleration (c) Later – electromechanical velocity 36. Rhumble occurs (a) P & D valve malfunction (b) FCU malfunction (c) Fuel nozzle partially clogged (d)All of above 37. Which component is not mounted on engine? (a) Boost pump (b) Pressure pump (c) P & D valve 38. Mark correct statement regarding oil pressure indicating system (a) Thermocouple (b)Autosyn (c) Temperature build 39. Anti icing valve is used for (a) To avoid ice formation 40. in fuel metering valve (a) Orifice area is varied (b) A constant fuel pressure across valve (c) 1 and 2 are correct 41. Which is fire-extinguishing agent? (a) Freon (b) Bromochloro difloromethane (c) Bromo fluoromethane (d)All of the above 42. Trimming is carried out when (a) FCU is changed (b) Specific gravity of fuel (c) For performance recovery (d)All of the above
18
SUBJECTIVE QUESTIONS 1. a. Explain active clearance control in the modern turbo fan engine b. Method of turbine blade cooling with fig c. Field cleaning 2. a. Explain the breather system with diagram b. Show thrust Vs air speed of turboprop turbofan and turbojet engine 3. a. In axial flow compressor why gas flow path is made convergent explain b. What is the advantage of squalor blades? c. What is bleed band how to check explain? 4. a. If mass flow rate is 60 lb/sec/engine and exhaust gas velocity is 1300 ft sec for a turbojet engine ready for the take off find out gross thrust of each engine b. Draw by graph effect air thrust for following variable (i) Speed of a/c (ii) RPM (iii) Altitude (iv) OAT 5. a. Which type of turbine is used in air turbine starter explain b. What is engine inlet roster clissipate? c. Advantage of reverse flow combustor, explain the work d. What are advantage of free power turbine and where it is used?
19
JET ENGINE (JUNE 98) 1. Internal energy of a gas depends upon its (a) Pressure (b)Temperature (c) Volume (d) None of the above 2. When mechanical energy is converted into heat energy or vice versa an exact equivalent exists between the two. This is stated in the (a) First law of thermodynamics (b) Second law of thermodynamics (c) Third law of thermodynamics (d) None of the above 3. During starting an engine stabilizes at idle r.p.m and JPT (a) Check for whether oil pressure is correct (b) Check for whether oil temperature is correct (c) Check for whether generator output is correct (d)All of the above correct 4. Mark the correct statement (a) Fuel trimmer is provided so that the relationship between fuels flow an r.p.m. Can be varied without using fuel lever (b) Because the mass flow inside the engine change with atmospheric conditions (c) Trimmer is adjusted to provide given JPT. (d) All of the above are correct 5. During start engine rotates but fails to light up one suspect (a) Ignition system fault (b) Fuel pressure control system fault (c) Both a and b (d) Battery capacity is low 6. During inspection of centrifugal compressor blades normally (a) No crack is allowed in the leading edge trailing edge and blade tips (b) Negligible crack is allowed as in (i) up to minimum extend possible and under constant monitoring (c) Nicks dents in the leading edge, trailing edge and blade tips not allowed (d) None of the above 20
7. The lowest r.p.m. at which a rotating object vibrates (a) Resonance (b)Natural frequency of vibration (c) Harmonics (d) All of the above 8. Mark the correct statement (a) At high power settings the noise generated from the compressor blade is Predominant (b) Noise from the compressor is of lower frequency (c) Low frequency sounds can be attenuated easily (d) None of the above 9. Characteristics of P & D valve (a) Dump valve is spring loaded close (b) Pressurizing valve is spring loaded open (c) Pressurizing valve limits starting fuel to primary manifold (d) All of the above 10. In a jet engine V.S.V and variable I.G.V are a part of (a) High pressure system (b) Low pressure system (c) Accessory drive (d) None of the above 11. Modular construction in a jet engine (a) Enables maintenance with limited repair (b) Enables maintenance with major repair (c) Modular maintenance involves more of repair rather replacement (d) Both b and c 12. Smoke from tail pipe. Most probable cause is (a) Main oil filter contaminated (b)Blocked scavenge port of bearing housing (c) Both a and b (d) None of the above 13. In a flight from Delhi to Bangalore, excess oil was consumed than required most probable cause could be (a) Defective centrifugal breather carbon seal (b) Main oil filter contamination (c) Oil leak from contamination (d)Both a and b 21
14. In the relation P.V X T the term X is proportional (a) Mass of the gas molecules (b) No of gas molecules (c) Pressure volume and temperature (d) Average K.E of the molecules 15. If a system is perfectly conducting to the surroundings and the temp remains constant the process is (a) Isothermal (b)Adiabatic (c) P.V constant (d) Both b and c 16. An aircraft is designed to fly at 350 m.p.h. (a) Jet engine becomes the choice (b)Propeller (c) By pass engine (d) None of the above 17. An airplane has an engine providing 4000 lb thrust at 300 m.p.h the thrust horsepower is (a) 4000 b.h.p. (b)3200 (c) 12800 (d) 5000 18. Increase in the turbine disc diameter under hot running (a) Disc growth (b)Disc rock (c) Has effect of reducing tip clearance as engine run time increases (d) All of the above 19. When change in pressure and volume of a gas take s place without change in temperature the process (a) Is very slow (b)Obeys boyle’s law (c) Adiabatic change is quick (d) All of the above 20. Oil pressure continuously fluctuates (a) Indicates is faulty (b)Pressure relief valve is sicking and contaminated (c) Both a and b (d) Oil check valve setting is improper 22
21. After flight is over engine does not shut down (a) Loose connection of power lever linkage (b)Fuel control shut off valve is faulty (c) Power lever rigging is improper (d) All of the above 22. After engine starts the engine hesitates for 5-6 seconds go for (a) Surge bleed valve check (b) Solenoid controller check (c) Fuel pump functional check (d) All of the above 23. During testing of engine, hooting/ humming sound is heard (a) Operation of compressor bleed valve is improper (b) Condition of the bleed valve diaphragm is bad (c) Both a and b 24. for M.E.C and P.M.C (a) M.E.C provides an electronic override of P.M.C to set corrected fan speed (b)P.M.C provides an electronic override of M.E.C to set corrected fan speed (c) P.M.C is located in the tail of the engine (d) None of the above 25. Start valve can be operated (a) Manually (b) Electrically (c) Opening /closing is indicated by pneumatic pressure (d) All of the above 26. In engine starter system (a) Compressed air pressure is converted to rotational mechanical energy (b) Reduction mechanism of gear train converts low speed high torque of turbine wheel into high specific low require through a pawl and ratchet mechanism (c) Starter operation is not controlled by start valve (d) None of the above
23
Jet Engine (Feb 2003) 1. If jet velocity is 1288ft sec & airflow is 125lb what will be thrust produced? (a) 4000 lb (b) 6000 lb (c) 5000 lb (d) 3500 lb 2. If atmospheric temperature change but EGT remains unchanged during ground run but every define high power cruise flight then snag/fault is in (a) CIT (b) CDP (c) FCU (d) FCU altitude adjuster 3. In a turbo fan engine airflow is 60 lb in both fan and core engine exhaust and velocities are sec & -------- ft / sec what will be thrust produced? (a) 1433 lb (b) 5433 lb 4. CIT indicator in turbojet engine is (a) Copper constraint (b) Nickel platinum (c) Chromel alumel (d) All of the above 5. FACDEC means (a) Full authorized digital electronic control (b) Full authorized digital electronic control 6. Synchronous motor type fuel quantity gage measures (a) Fuel volume flow (b)Fuel mass flow (c) Its same of vane type indicator (d) As 02 & 03 7. In water injection system EGT is increased water injected at (a) Inlet (b) Diffuser (c) Nozzle (d) Simultaneous inlet & diffuser 8. If water injection is ON then 24
(a) N1 spool shifts towards stall margin (b) N1 spool shifts away stall margin (c) N2 spool shift away stall margin (d) N1 & N2 shift away stall margin 9. High power to weight ratio is (a) Starter motor (b) Starter generator (c) Air turbine starter (d) Ratchet & pawl 10. During installation of thermocouple length of sensor is increased then (a) Under read (b) Over read (c) Equal read (d) None of the above 11. during feathering of the propeller (a) Pitch angle fine (b) Pitch angle course more (c) Pitch angle negative (d) As 1 & 2 12. Aluminum propeller is cleaned by (a) Acid (b) A caustic solution (c) None of the above 13. Due to fatigue stress in turbine blade (a) Change of shape (b) Cracks in the trailing & leading edge perpendicular to length (c) Length will grow (d)All of the above 14. Due to fatigue stressing turbine blade (a) Change of shape (b) Cracks in the trailing & leading edge perpendicular to length (c) Length will grow (d)All of the above 15. In which engine air speed kinetic energy at inlet is not changed in the static energy (a) Turbofan (b) Turbojet (c) Turbo shaft 25
(d) Turbo prop 16. Synchronous system in propeller is used in (a) Single engine to equal the blade angle (b)Multiengine to allow same speed of engines (c) As 1 & reduce vibration (d) All the above 17. During flight which fault is not monitored by performance monitoring (a) EPR, EGT, PRM (b) EPR, EGT max, CIT (c) CIT, CDP, EGT max (d) CIT, CDP. EGT, RPM 18. If oil is found in exhaust (a) Replace engine (b)Seal leakage at bearing shaft (c) Carbon seal leakage in turbine shaft (d) Scavenge pump failure 19. Mark the correct statement (a) Pressure pump capacity is greater than scavenge pump capacity (b)Scavenge pump capacity is greater than pressure pump (c) Both pump capacity are same 20. Gas velocity is high at (a) Inlet (b) Compressor (c) Turbine (d) Diffuser 21. Mark correct statement (a) Supervisory EEC develops command top actuate FCU (b) Supervisory EEC directly controls FCU (c) Supervisory EEC and sigma Hydro-mechanical fuel control unit (d) All of above 22. Mark correct statement (a) ACC controls tips clearance by cooling turbine case 23. Mark the correct statement (a) Turbo jet engine has lowest TSFC (b) Turbo fun has better hot day performance (c) Turbo fan has lowest TSFC up to 400 mile / hour 26
(d) All of the above 24. Mark correct statement (a) Actual power output of engine as compared to the horsepower in fuel is thermal efficiency (b) Propulsive efficiency is the thermal efficiency 25. What is the effect of combustion emissions? (a) Populates surrounded area 26. EPNAB means effective perceived noise decibel (a) Sound is dissipated at distance (b) It is standard measure of the loudness (Sound or) combined with frequency and duration of sound and is used specify for a/c noise in hemisphere (c) Soap - spectrographic oil analysis port – spectrum tric oil analysis program 27. Mark the correct statement (a) In the flight CDP failure cause to run engine in idle (b)During starting CDP failure cause huy start (c) During ground CDP failure will cause to run engine idle (d) Any time CDP failure to run engine higher rpm 28. Polished shaft is used for which bearing (a) Carbon bearing (b) Labyrinth bearing (c) Nylon bearing (d) All of the above 29. Trimmer coil add in ignition system is (a) Convert AD to DC (b)Convert DC to AC 30. Difference between hi voltage of 10-voltage ignition (a) High voltages have high energy than 10 voltages 31. During oil analysis mg is gived Hi then a practice gear of problem in gearbox 32. in the good combustion chamber (a) Increase velocity (b)Diffuse (c) Convert pr to kinetic energy (d) As 1 or 2 27
33. In hi energy capacitor ignition system (a) In hi energy capacitor ignition system (b) High energy is produced spark (c) Hi energy is produced spark using short time (d) Lo energy is produced spark using short time 34. Acceleration of deceleration is controlled for (a) Blow out provision (b) Crack of leading of blade and case (c) Expansion and contraction of blade and case (d) None of the above are correct 35. In HMF unit hydro mechanical fuel unit (a) Valve area is varied (fixed pr. df) 36. For good lubrication oil used synthetic oil (a) Minimum wax sulpher us sediment (b) Operates in hi temp is gives low vapour (c) Very load carrying capacity (d)All of the above 37. If anti ice valve is operative in flight then what is positive mean of finishing that anticity system working properly (a) EGT increase (b) RPM & EPR fluctuation (c) Fuel flow rate (d)As in 1 & 2
JET ENGINE SUBJECTIVE 1. What is cascade, how it helps turbofan / turbojet engine explain? 2. Wright the types of thrust reverser. Explain mechanical blockage type with sketch 3. What are the advantage & disadvantage of centrifugal compressor? 4. What is primary principal of pressurization breather system explain pressurization breather system with sketch how it works? 5. What is vortices dissipater explain with sketch? 28
6. Explain the operation of HMF unit metering vale with sketch? 7. What are causes of oil temperature high give remedial action for each cause? 8. What are the combustor emissions give their effect? 9. Wright the operating principal of turbojet and ice separator inlet screen? 10. What are the forces acting on rotating propeller explain each? 11. Wright principal of Hamilton propeller feathering with sketch? 12. Explain the procedure for finding ------------ of the oil engines? 13. What is slip explain? 14. Explain how turbofan engine is replacing turboprop engines 15. What are the FOD avoiding precautions turboprop engines? 16. Using Newton’s seonel 100 of notion derive formula for thrust calculation 17. What is the not streak explain give reason for streak 18. FFX, FPM & EGT northern what are causes remedial action?
29
JET ENGINE (JUNE 2003 ) 1. Torque meter is used in (a) Turbofan (b)Turbo shaft (c) Turbo prop (d) All of the above 2. Mark correct statement (a) Throttle control & propeller control is interconnected I the ground operation (b) In flight propeller control is interconnected in the ground operation (c) Both 1 & 2 3. If throttle of constant speed propeller is reduced slightly (a) Pitch angle reduce (b) Pitch angle increase (c) Pitch angle remains same (d) Pitch angle will reverse 4. Anti icing operation check is viewed by (a) Fluctuation of RPM (b) Fluctuation of EPR (c) Flickering of anti icing valve (d)TGT increase 5. Notch in turbine blade is (a) To measure wear (b) Relieve stress (c) Giving thickness (d) Air seal 6. Aluminum propeller blade cleaning is done by (a) Acid (b) Caustic soda wash (c) None 7. Mark the correct statement (a) Governor speed progressively increases as load added (b)Governor speed progressively decreases as load added (c) Governor speed remains constant as load added (d) Governor speed remains constant as load removed 30
8. Mark the correct statement (a) Governor droop is decrease of speed when load added (b) Governor droop is increase of speed when load unloaded (c) Droop makes stable (d)All of the above 9. Mark the correct statement regarding ass flow rate (a) Proportional to pressure & inversely proportional to temperature (b) Proportional to pressure & temperature (c) Proportional to temperature & inversely proportional to pressure (d)Proportional to temperature & inversely proportional to square root to temperature 10. In modern APU (a) Load control valve can be adjusted only after shut down (b)Load control valve works in conjunction of surge valve (c) Clockwise rotation of trimming means increasing (d) All of the above 11. Compressor blade is loose fit due to (a) Reduce vibrational stress (b) Ease of removal (c) Temperature compensation (d)All of above 12. If EPR reads 2.4 then turbine discharge pressure is 2.4 times of (a) Inlet static pressure (b) Inlet ram pressure (c) Ambient pressure (d)Compressure inlet total pressure 13. Last chance filter in the oil system screen type (a) Cleared during engine overhaul (b) Prevent clogging of jet (c) Cleaner during 100 hrs inspection (d)Both 1 & 2 14. Engine preservation depends on (a) Times remains inactive (b) Duration of preservation (c) Depends on engine rotation (d)All of the above 15. Mark correct statement regarding double entry centrifugal compressor (a) Prevent tip velocity loss 31
(b) Air entry from both side of compressor
(c) Required big inlet chamber (d)All of the above 16. After burner thrust augmentation (a) Thrust of basic engine can be increased (b) Thrust increase by after burner for take off climb for military aircraft (c) Both 1 & 2 are correct (d) None of the above 17. If JPT is high then water is injected in (a) Inlet (b) Diffuser (c) Both (d) Combustion 18. If water is injected in the diffuser (a) Mass flow increased in entire engine (b)Less pr. & temp drop in turbine hence more pr. in tail (c) All are correct 19. I water in injected in the inlet and diffusers (a) N1 shift towards surge (b) N1 shift away surge (c) N2 shift away surge (d) Both N1 & N2 away surge 20. Variable propelling nozzle is used due reduce TSEC (a) By pass engine (b)After burner (c) Water injection (d) All of above 21. Velocity in combustion chamber is reduced (a) Increased static pr (b)Ease of burning 22. Stable combustion means (a) Low emission (b) Combustion alighted over long range (c) As 1 & 2 23. In can annular liner (a) Continues shroud 32
(b) Circular & outer (c) Inner & cylindrical (d) As 2 & 3 24. Mark incorrect statement regarding combustion chamber drain valve (a) Mechanically operation by spring force (b) Failure of valve gives false start (c) Located in LH or RH side bottom (d) None of the above 25. Canted vanes in the first few stage of compressor (a) Increase pressure (b) Increase velocity (c) Increase temperature (d)Reduce boundary layer separation 26. Knife edge (profile) blade (a) Wears & sets tip clearance (b) Used in supersonic aircraft (c) Is not used (d) Used in turbine blade 27. Repair of compressor or fan blade is called (a) Grinding (b) Brinelling (c) Galling (d)Blending 28. Balancing of compressor (a) Individual stage is balanced (b) As a unit balanced (c) Both 1 & 2 (d) Not required 29. Turbine blade design is based on (a) Corrosion resistance (b) Creep (c) Fatigue & vibration resistance (d)Both 2 & 3 30. Fatigue stress causes (a) Elongation of blade (b)Crack in LE & TE (c) Change of shape (d) All of above 33
31. Mark current statement regarding radial inflow turbine (a) Air enters at eye & leaves at radial outward (b) Used in big engine (c) Air enters at peripheral nozzle & flows radial inward (d)As 2 & 3 32. Function of NGV is (a) Convert PE to KE (b) Convert KE to PE (c) Directs air perpendicular to bucket (d)As 1 & 3 33. In pure turbojet engine temperature drop across turbine is (a) Same as compressor (b)About same as compressor (c) Higher than compressor very low than compressor (d) Very low than compressor 34. For load balancing in the turbine rear stages (a) More turbine area is required (b) More length is required (c) Less turbine area is required (d) As 1 & 2 35. If exhaust nozzle area is decreased (a) CDP increases (b) CDP decreases (c) SFC decreases (d) As 1 & 3 36. What component prevent stall during low speed ground operation (a) Bleed valve (b) P & D Valve (c) Chock Valve (d) As 1 & 2 37. During starting starter & fuel flow are ok, but hung start cause is (a) CDP sensor loss (b)CIT loss 38. Mark correct statement (a) Engine running at high RPM & CDP lost then stabilize at idle (b) Engine running at idle RPM & CDP lost then stabilize at high RPM 34
(c) CDP lost during starting it is a hung start (d) All are correct 39. Minimum fuel flow is critical (a) Acceleration (b)Deceleration (c) Idle (d) Ground run 40. Which component is not installed in the engine? (a) Fuel pump (b) FCOC (c) Filter (d)Boost pump 41. Deareator is located in (a) Scavenge sub system (b) Pressure sub system (c) Inlet of the pump (d)Oil tank 42. After engine shut down oil found in the exhaust (a) Seal failure (b) Bearing seal failure (c) Replace engine (d)Air pressurization seal failure 43. Air tight seal is (a) Carbon seal (b) Ring seal (c) Multi grove seal (d) Threaded seal 44. Mark correct statement (a) Pressure pump capacity is scavenge pump (b)Scavenge pump capacity is more pressure pump (c) Both pumps capacity (d) As 3 & both are located in oil system 45. Mg is found in SOAP analysis then failure is (a) Gear (b)Gear box (c) Bearing (d) Bearing shaft 35
46. Oil SOAP analysis then failure is (a) Pin point impending failure (b) Take sample for entire engine life (c) First sample gives food analysis (d)As 1 & 2 47. Property of lubricating oil is (a) High flash point (b) Low flash point (c) High pore point (d) Low viscosity index 48. Synthetic oil is used in turbojet engine (a) Corrosion resistance (b) Low carbon / wax formation (c) High temperature operation (d)All the above 49. Input to hydro-mechanical FCU (a) Burner pressure compressor inlet pressure EGT (b) Burner pressure compressor inlet pressure, RPM 50. in part EEC system (a) Control till part throttle and then switch off. (b) It is like FADEC 51. in supervisory EEC (a) Develops command (b)Control standard hydro-mechanical system (c) Control valve (d) As 1 & 2 52. Acceleration & deceleration control is (a) Flam blow out (b) To prevent over flow (c) For max speed 53. High power to weight ratio is in which starter (a) Electric starter (b) Starter generator (c) Air turbine starter (d) Pawl & ratchet starter 54. White repair AME increased length of thermo-couple (a) Over read 36
(b)Under read (c) No effect (d) Over read at hi temperature 55. During feathering pitch angle (a) Course & higher (b) Low pitch (c) Course (d) Negative 56. Propeller locks LP solenoid 57. EGT gauge yellow amber arc (a) Maximum continues to maximum permissible (b) Minimum to continue (c) Maximum (d) As 1 & 2 58. Torque is measured by (a) Helical gear (b) Rack & pinion (c) Spur gear (d) Planetary gear 59. As altitude increases stall margin (a) Reynolds No. Effect (b) Increases that’s why aircraft flying only at high altitude (c) Decreases 60. Trimble coil in ignition system (a) Connected parallel to primary capacitor (b) Connected series to primary capacitor (c) Not used in ignition system (d) Used in starting system 61. Shaft engine forward bearing is (a) Ball bearing (b) Roller bearing (c) 1 + is locator bearings (d)2 + is takes radial load 62. MCS (a) APU generator frequency is maintained by CSD and is constant speed rated 37
(b) APU does not have CSD in its operation and is constant speed rated (c) APU generator requires axial flow compressor and is constant speed rated (d) Both B and C are correct 63. MCS (a) In turbo-jet TSFC increases as airspeed increases (b) In turbo prop TSFC decreases as airspeed increases (c) In turbo prop TSFC increases as airspeed increases up to 450 mph (d)Both A and B are correct 64. MCS (a) Temp drop through turbines is greater than that of temp rise through compressor (b) Temp drop through turbine is same as the temp rise through same no of stages of compressor (c) Temp drop through turbine is about the same as that of temp rise through compressor (d) Temp drop through turbine is less that that of temp rise through compressor 65. TSFC is (a) Directly proportional to the rpm (b) Directly proportional to the efficiency (c) Inversely proportional to the efficiency (d) Directly proportional to the compressor ratio 66. Primary function of inlet duct is (a) To convert kinetic energy of rapidly moving air stream into ram pressure rise (b) To convert potential energy into kinetic energy inside the duct (c) To convert potential energy into ram pressure rise inside the duct (d) To convert kinetic energy into potential energy outside the duct 67. Compressor inlet screens (a) Are found in rotorcraft TPE and ground turbine installations (b) Are sued mostly in axial flow turbojet engines (c) A + have problems of icing and fatigue failure (d) B + if fitted they may be located either the inlet or the compressor inlet 68. Two shaft whose axes are at an angle to one another but in the same plane to gear used (a) Bevel gear 38
(b)Spiral bevel gear (c) Spur gear (d) Helical gear 69. Prime requirement for stator vanes is (RR31) (a) Corrosion resistance (b)Fatigue strength (c) Smooth surface finish (d) Heat resistance 70. Function of P & D valve is (a) Flow divider (b) Dumping fuel after engine shut down (c) Fuel pressure control (d)All of the above 71. Propulsive efficiency of high by pass turbofan is high due to (a) Same length (b) Small turbine (c) Small dia. (d) All correct 72. AME’s knows OAT is significantly shifted but TGT is same at ground. In the high power run every thing is normal then snag is (a) CIT system (b) CPP system (c) FCU temperature compensator (d) Throttle missrig 73. Trimming means (a) Adjusting idle & max power (b) Adjusting exhaust nozzle (c) Adjusting throttle for full forward (d) All of the above 75. There is a problem in the turbine then (a) Vibration increases with RPM increases (b) Vibration decreases with RPM increases (c) No change of vibration (d) None of the above 76. Ignition plug correct statement (Compare to PE) (a) Wider gap (b) Less fouling problem due to high spark (c) As 1 & 2 39
77. Propeller feather (a) Electric cut out switch 78. Part throttle (a) Throttle movement less than full forward
JET ENGINE ( OCT 2003 )
40
1. Engine performance check needed (a) To see mechanical integrity of the engine (b) Instrument check (c) Power check (d) All are correct 2. Modern aircraft engines (a) Have many drain holes at different location to drain volatile fluid used inengine (b) There are no such drain holes provided (c) FCOC has provision for draining (d)Both A and C are correct 3. MCS (a) Compressor and turbine discs are forged by powder metallurgy (b) Compressor blades and vanes are generally cast (c) Turbine blades and vanes are made by lost wax method (d)All are correct 4. Run down time is (RR 261) (a) Time taken by the engine to come to rest after closing the shut off valve (b) It gives indication of wear or rubbing inside the engine (c) Wind velocity and direction may affect the RDT of an engine (d)All are correct 5. Sound suppressors used in gas turbine engine to (a) Reduce energy (b)Increases frequency (c) Increase eddies (d) All are correct 6. MCS regarding jet cal analyzer (a) Used to check EG thermocouple during engine run or without running (b) Used to check continuity and resistance of the EGT circuit during engine run only (c) Used to check % rpm. During engine run only (d) Both B and C are correct 7. Oil pressure indicating system is (a) Auto sync (b) Thermocouple (c) Resistance 41
(d) Synchronous 8. Major disadvantage of air turbine starter is (a) It produces low torque (b)Requires high volume of airflow (c) Complex construction (d) Limited to small engine 9. MCS (a) Igniter plugs have problem of corrosion of case, and after prolonged use it get eroded (b) The audible test for proper ignition check is not possible in synchronous ignition (c) Iridium inserts are placed in the tip to prolong its lift (d)All are correct 10. Engine inference (a) Nozzle diaphragm area is measured at the exit of the vanes (b) Total outlet area measured is the sum of all areas of the passages between the vanes (c) Nozzle area effects the efficiency of the engine (d)All are correct 11. Hydromantic pitch propeller (a) Is constant speed counter weight type propeller (b) As in A also used for full feathering (c) As in B also used for reversing operation (d)As in C also used for maneuverable pitch change 12. Oil found in gas path (a) Inoperative scavenge pump (b) Fuel leak in oil system (c) Low vent pressure (d) None of the above is correct 13. When water is injected in inlet alone (a) N1 will move away from stall (b) N2 will move away from stall (c) N1 will move towards stall (d) Both N1 and N2 will move away from stall 14. Trimming is carried out (a) To set idle to max rpm 42
(b) To adjust acceleration and deceleration (c) To limit exhaust gas temperature (d) To set compressor bleed valve opening 15. In centrifugal compressor engine thrust is determined by (a) RPM (b) EPR (c) EGT (d) TORQUE 16. Increasing NGV area will cause (a) N1 increase (b) N1 decrease (c) TSFC decrease (d) N1 no change 17. For a given compressor rpm if airflow increase (a) Compression ratio increases surge margin decreases (b) Compression ratio increases surge margin increases (c) Compression ratio decreases surge margin increases (d) Compression ratio increases surge margin increases 18. If bypass valve is fitted across the metering valve, and P1 is inlet pressure and P2 is outlet pressure then constant fuel pressure differential is depends on (Tr.273) (a) P2 – P2 (b) Orifice area (c) Metering valve (d)Bypass valve 19. Two internal sections of an engine are subjected to different air per seel to be used (a) Thread seal (b) Ring seal (c) Multi grooved seal (d) Carbon seal 20. The afterburner engine liner is perforated (a) Which is cooled by secondary air (b) Leads to screech (c) A and B are correct (d) None of the above 21. In a hydro mechanical torque meter if the temperature of oil is increased causes 43
(a) High torque reading (b)Low torque reading (c) No change (d) Any of the above 22. Most prevalent condition for icing is (a) High rpm low airspeed (b)High rpm high airspeed (c) Low rpm low airspeed (d) High rpm high velocity 23. MCS (a) Electrical heaters are mostly preferred than pneumatic heating for anti-icing system (b) Isopropyl alcohol or phosphate compounds are used for deicing system (c) Anti icing heating is commanded through cyclic timers (d)None of the above 24. Turbo shaft with free turbine, its speed is controlled by (a) Ng governor (b) Nf governor (c) Idle governor (d) Not controlled by governor 25. The oil system used by VTOL engine is (a) Full flow (b) Hot tank (c) Total loss (expandable) (d) Pressure relief valve 26. In full flow oil system quantity of oil flow is determined by (a) Take off (b) Cruise (c) Ground idle (d)All rpm range 27. in test house first and last test carried out after overhaul is (a) Vibration survey (b) Hot air leak (c) Engine power setting 28. Factory ignition depends upon (a) Volatility of fuel (b) Specific gravity 44
(c) Viscosity (d)As in A atomization 29. MCS (a) Turbojet engines used annular combustion for shorter length (b) Turbojet engines used reverse flow combustion for shorter length (c) Turbofan engines give best performance (d)B and C are correct 30. Compression in an axial flow engine is (a) Isothermal (b)Adiabatic (c) Isometric (d) Isobaric 31. Decreasing nozzle area will cause (a) Pt7 up* (b) Pt7 down (c) Tt7 down (d) No change 32. Part time fuel control (a) Used for part power trim (b) Operates in adverse condition (c) Operates like hydro mechanical fcu up to max. Power then amplifier takes care (d) Operates like FADEC 33. Last chance filter is used in (a) Oil system (b) Fuel system (c) Oil tank (d) Deairator 34. If Pt2 is partially blocked by ice formation (a) EPR will increase (b) EPR will decrease (c) EPR will fluatuate (d) EPR will not change 35. More than one weld is not carried out in deicing element because (a) Increases circuit resistance of element (b) Decreases circuit resistance of element (c) It will damage the element (d) All the above may happen 45
36. The function of selector valve is post exit thrust reverse is (a) It gives command for reverse operation (b) It selects the actuator valve to operate thrust reverse (c) T operates the hydraulic valve to slow and deploy thrust reverse (d) None of the above 37. Most commonly used oil in gas turbine engine is (a) Petroleum (b) Akyl diestar (c) Polyester (d) Mineral 38. Mark INCORRECT statement (a) Screen type filter is used in low pressure (b) Cartridge type filter is used in low pressure (c) Screen disk type filter is used in low pressure (d) Cone shaped filter element is used in screen type filter 39. In turboprop power lever is interconnected to (a) Throttle lever (b)Propeller lever (c) Condition lever (d) Governor 40. MCS (a) For a given torque weight of starter generator is less than air turbine starter (b)Starter generator windings are separate (c) Duty cycle of starter generator is more critical than air turbine starter (d) None of the above 41. In turboprop during starting the positions of levers are (a) Throttle lever at idle and propeller lever at high pitch (b) Throttle lever at idle and propeller lever at nay position from high to low pitch (c) Propeller lever at idle throttle lever at idle (d)Throttle lever at idle and propeller lever at low pitch setting 42. If oil quantity is increased cause is (a) Scavenge pump failure (b)Food faculty (c) Bearing pressure loss (d) All of above 46
43. During starting satisfactory condition for combustion is (a) Low pressure, high temp, low velocity (b) High pressure, high temp, high velocity (c) Low pressure, high temp, high velocity (d)High pressure, high temp, low velocity 44. Gradual darkening of oil is due to (a) Degraded oil is used (b)Inhibitor performing its function properly (c) Excessive air leak in to the oil (d) All are correct 45. MCS (a) Oil bypass valve is installed at inlet (b) Oil flow through passages depend on the operation (c) If problem occurs fuel will flow into oil (d) All are correct 46. Thrust of turbofan measured in test cell by (a) EPR (b) EPR/NI (c) Torque meter (d)Thrust meter 47. In post exit thrust reverse is deployed by (a) Isolator valve (b)Selector valve (c) Shut off valve (d) Shuttle valve 48. In a constant displacement pump the output volume is 10 gph it actually (a) Delivery (b)Displacement (c) Volumetric efficiency (d) All are correct 49. MCS (a) The seal which rides on highly polished surface is carbon seal (b) Carbon seals are used in vent pressurization system (c) Both A and B are correct (d) None of the above is correct 50. In reheat engine with reheat operation 47
(a) Dry EGT is high (b) Dry EGT is low (c) No effect on EGT as it remain same (d) Wet EGT is high 51. Safety feature incorporated in air turbine starter (a) Starter shaft with shear neck section shears off when over speeded (b) Starter turbine gets chocked in case of air inlet valve failure (c) Any malfunction occurs magnetic chip detector inspection is carried out (d)All are correct 52. Most important property of turbine blades (a) Corrosion resistance (b)Creep resistance (c) Vibration resistance (d) Fatigue 53. Property required in NGV (a) Corrosion resistance (b)Heat resistance (c) Creep resistance (d) Fatigue resistance 54. Prist used in fuel for (a) Anti-icing (b) Anti-biocidal (c) A and B are correct (d) Anticorrosive 55. P & D valve senses (a) Electrical signal (b) Rpm (c) Inter stage pump pressure (d) All of above 56. Function of NGV (a) To increases the pressure at its outlet as per Bernoulli’s theorem (b) To deflect the gases at desired angle (c) As in B to increase the velocity of gases at its outlet (d) None of the above 57. If any fault occurs in FCOC (a) Oil will flow into fuel (b) Fuel will flow into oil 48
(c) Fuel quantity will increase (d) None of the above 58. Water methanol is injected at inlet of compressor (a) Increases mass airflow through whole engine (b) Increases the fuel flow (c) Both A and B are correct (d) None of the above 59. Output of gear rotor pump (a) Proportional to the missing tooth multiplied by no. of teeths on outer gear 60. Breather pressurization system (a) Keeps the constant pressure in the sump for positive flow of oil (b) Ensures positive flow of oil to the bearing chambers 61. Angle of blades during starting of turboprop (a) Fine pitch so that minimum resistance on blades (b) Coarse pitch so that minimum resistance on blades (c) Any angle so that EGT should not exceed limit
JET ENGINE(OCT 2000)
49
1. LIST & EXPLAIN NON DESIGN FACTORS AFFECTING THRUST 2. LIST FIVE ALLOYS THAT ARE USED IN THE CONSTRUCTION OF GAS TURBINE ENGINE. DE? 3. PROPERTIES OF EACH THAT MAKE IT ESIRABLE FOR USE IN SPECIFIC LOCATIONS IN THE 4. DRAW BLOCK DIAGRAM & EXPLAIN A TYPICAL FUEL SYSTEM 5. DESCRIBE THE GAS FLOW THR A TYPICAL REVERSE FLOW ANNULAR COMBUSTION CHAMBER REQUIREMENTS OF GOOD THRUST REVERSER 6. WHAT DO YOU UNDERSTAND ABOUT COMPRESSOR STALL LIST THE METHODS TO PREVENT 7. COMPRESSOR STALL & EXPLAIN ONE 8. ADVANTAGES & DISADVANGES OF AXIAL & CENTRIFUGAL COMPRESSOR & APPLICATION 9. CHARACTERISTICS ADVANTAGES & DISADVANTAGES OF a. TURBOPROP b. TURBOFAN c. TURBOJET 10.EXPLAIN WHAT IS MEANT BY PERFORMANCE MONITORING & DISCUSS IT’S IMPLICATION 11.IMPROVE RELIABILITY OF ENGINE 12.PROCEDURE FOR LONG – TERM STORAGE (PRESERVATION) OF ENGINE OBJECTIVE 1. A large jet engine handles 100 lb. Sec of air the velocity of this air at the jet nozzle is 659 mph what is the thrust of the engine F MA F = (Wa / g) A = (100/32.2) (659*1.467) = 3002 LB **(initial speed = 0) Mark correct statement 1. What the gross thrust is computed (a) The velocity of the air coming into the engine due to velocity of airplane is disregarded (b) The loss in thrust involved in taking air in at the front of the engine is known as ram drag, Net thrust is then gross thrust minus ram drag (c) As in (1) & (2) (d) None of the above 50
2. The complete formula for a turbojet engine with a choked nozzle is Fn = (Wa/g) (v2-v1) + (Wf/g) Vf + Aj (Pj-Pam)* 3. MCS 1. The rated net thrust of any engine is determined by how much the forward thrust forces exceed the rearward forces 4. MCS 1. At higher altitude pressure continues to drop sharply W.R.T temperature resulting Sharp drop in thrust 5. MCS 1. Brayton cycle called open cycle 6. Ram recovery point is that 1. A/c speed, which the ram pressure rise is equal to friction pressure losses 7. Engine mfr rate their engine by Bell month inlet duct 8. British thermal unit is a standard measure of energy defined as the amount of energy reqd to raise the temperature of 1 pound of water to 1degree faranhit at (a) Constant pressure (b) Constant volume (c) Constant mass (d) None of the above 9. Can annular combustion chamber (a) Greater structural stability & lower pressure drop (b) Outer case made to slide for line inspection (c) As in 1 & 2 (d) None of the above 10. A unique cooling concept reduces cooling air requirements by 50% & decrease weight by 20% the combustor is (a) Annular (b) Can annular (c) Can type (d) Fin wall 11. Noise protection device is required (a) Frequency up to 100db 51
(b) As in 1 with ear plug (c) Frequency up to 160db (d) As in 2 with ear protector 12. Water injection coolant freezing point Any increase in back pressure from exhaust nozzle affects (a) R.P.M (b) Compressor stall (c) E.G.T (d) All above 13. After burners spray bars Turbine vane/blade cooling figure (a) Convection (b) Impingement (c) Film (d) All above 14. In fuel flow control one of the method is (a) Keeping pr. Drop constant & varying orifice area 15. Droop can be reduced (a) By using weaker spring (b) Marking orifice opening more radially (c) Using by increasing the pressure drop (d) All above 16. For the fuel pump containing two stages the possible connections are (a) Series (b) Parallel (c) Series-parallel (d) All above 17. Fuel passage drilled at right angle (a) Fuel is discharged with a swirling motion in order to provide low axial air velocity & high flame speed (b) Fuel is discharged with a swirling motion in order to provide high axial air velocity & low flame speed (c) As in air shroud surrounding the nozzle cools the nozzle tip & improves combustion by (d) As in reduce the accumulation of carbon deposits on the face 18. High oil consumption (a) Defective scavenge pump (b) High sump pressure 52
(c) As in 1 & 2 19. High intensity means A lethal charge is present Identify the figure of igniter plug Low voltage shunted surface gap An turbine starter not reaching cut-off self accelerating speed reason (a) Rotary switch in regulator v/v is not adjusted (b) Shear off drive shaft (c) As in 1 & 2 20. Trend monitoring analysis (plot of EGT, N1, N2, VIB, F/F vs TIME) (a) 1st stage NGV failure (b) 13th stage bleed v/v cracked (c) Turbine case separation (d) All the above 21. SOAP TEST (a) Pin point the impending failure (b) Used for trend monitoring (c) As in 1 & 2 22. Gap between THUMB & FOREFINGER denotes Slight adjustment Starting sequence of engine is Starter ignition fuel 23. Identify seal in figure (a) Labyrinth seal (b) Carbon rubbing seal (c) Magnetic seal 24. Helicopter uses gas turbine engine (a) Turbo shaft with free turbine (b) Turbo shaft with fixed turbine 25. Shrouded turbine tip provides (a) Long blade thin tig (b) Reduced distortion under load (c) Dampen the vibration (d) All above 26. Shingling is due to (a) Compressor stall (b) F.O.D (c) Over speed 53
(d) All above JET ENGINE GENERAL 1. Inlet guide vanes are not present in turbofan engine, in order to (a) Reduce noise level (b) Reduce weight of the engine (c) Increase mass airflow 2. Turbojet engines having axial-flow compressors have what type of rear bearing (a) Ball (b) Roller (c) Taper-roller (d) Needle-nose 3. Some high volume turboprop and turbojet engines are equipped with tow spool or split compressors. When these engines are operated at high altitude (a) Throttle must be retarded to prevent over speeding of the two comp. Rotors due to low density air (b) Throttle must be retarded to prevent over speed of H.P rotor due to low density air (c) L.P rotor will decrease in speed as compressor load decreases in lower density air (d) L.P rotor speed does not change with altitude 4. In a gas turbine engine firewalls are provided (a) To separate the hot zone and the cold zone (b) To prevent the fuel leaking from the fuel lines to come from the hot section (c) Both are correct (d) None 5. The most modern method of cooling turbine blade and nozzle vanes is (a) Design of hollow blades and hollow nozzle vanes (b) Film cooling of vanes and blades (c) Reducing T.I.T 6. Swirling vanes are sued in fuel nozzles (a) For rapid combustion (b) To handle more fuel (c) To handle more air 54
(d) All are correct 7. Ice formation on engine is (a) More dangerous than on wing (b) Less dangerous than on wing (c) Equally dangero7d as ice formation on wing 8. Flame out occurs in the following condition (a) Lean flame out low fuel pressure high r.p.m high altitude (b) Lean flame out low fuel pressure low r.p.m, low altitude (c) Rich flame out low fuel pressure low r.p.m. low altitude 9. Blade twist is given (a) For constant air flow along the length (b) To distribute load along the blade length (c) To maintain constant outlet pressure (d) All of the above 10. At high altitude (a) N2-N1 is maximum (b) N1 rotor will rotate faster than N2 rotor 11. In a split spool compressor turbine as aircraft altitude increases (a) L.P spool increases in speed due to reduction in air density (b) H.P spool speed decreases to compensate density reduction (c) H.P spool speed increases to compensate density reduction (d) Both H.P and L.P spool maintain their original constant speed 12. For proper ignition of air/fuel mixture in the combustion chamber (a) High compressor discharge pressure high inlet temperature and low viscosity is ideal (b) High compressor discharge pressure low temperature and low velocity is ideal 13. In a combustion chamber flame out occurs if (a) There is disturbance in air-flow (b) Fuel nozzle is clogged (c) Igniter plug is faulty 14. In an axial flow turbine engine what type of rear bearing is mostly used? (a) Ball bearing (b) Roller bearing (c) Tapered roller bearing 55
15. Fuel trimming is done in the field only? (a) To up trim the engine (b) To compensate the thrust due to blades loss (c) To compensate the thrust due to contamination of the compressor blade 16. At high altitude (a) Surge line moves up as r.p.m. line moves down (b) Surge line moves downas r.p.m. line moves up (c) Surge line moves up as r.p.m. line moves up (d) Surge line moves down as r.p.m. line move down 17. Brayton cycle is known as (a) Constant pressure cycle (b) Constant volume cycle (c) Constant mass cycle (d) Constant combustion cycle 18. What would be the possible cause of a gas turbine engine to have as high EGT high fuel flow and low r.p.m. At all engine power settings? (a) Insufficient electrical power to the instant bus (b) Fuel control out of adjustment (c) Loose or corroded thermocouple (d) Turbine damage of loss of turbine efficiency 19. The speed of high pressure compressor is less than that HPT because ? (a) Turbine has more no of blades (b) Turbine and compressor have same no of blades (c) Turbine operates at high temperatures (d) Turbine area is more 20. During trimming at high humidity the effect on jet engine is (a) Increased P5 and decreased P2 (b) Increased engine trim (c) Decreased engine trim (d) No effect 21. Work done W by the compressor as shown when Sp is the specific heat, is expressed as (a) W = Sp (T1 – T2) / m (b) W = Sp. m. (T2 – T1) (c) W = m. (T2 – T1) / Sp (d) W = m. Sp (T1 – T2) 56
22. For a particular setting the compressor r.p.m. on a hot day compared to a standard day will (a) Increase (b) Decrease (c) Remain same (d) Nothing can be said firmly 23. Noise reduction at exhaust duct (a) Changes the low frequency to high frequency (b) Changes the high frequency to low frequency (c) Decrease the velocity of the exhaust gases (d) Decrease the pressure of the exhaust gases 24. The load distribution over a turbine blade as shown in the sketch is for (a) Impulse type blade (b) Reaction type blade (c) Impulse – reaction type blade (d) None of the above 25 Materials used in engine construction Compressor Gear box Combustion chamber Exhaust cone (a) Mg-alloy Cobalt Ti-alloy --(b) Ti alloy Mg-alloy Ni-alloy Cobalt (c) Ni-alloy Aluminum Ni-alloy Cobalt (d) Cobalt Magnesium Ni-alloy Steel 26. A tachometer reads 100% when it is being driven at 4200 r.p.m. If the tachometer drives gear ratio is 0.428:1, what is actual speed of the compressor? 27. Mark the correct statement: Surge is associated with (a) Sharp uncoordinated aircraft maneuvers (b) Thrust reverse operation (c) Afterburner operation (d) All of the above are correct 28. Match the following in pick up and O/p and O/p signals of the following instruments (a) Thermocouple D.C voltage (b) Accelerometer Charge thermocouple d.c. voltage 57
(c) Speed tachometer D.C signal speed tachometer – a.c. signal (d) Electronic fuel flow A.C. signal vibration pick – up – a.c. 29. If Pt2 blocks partially E.P.R. (a) Increases (b) Decreases (c) Remains the same (d) Constant 30. Low energy ignition exciter 31. Engine casing a hottest (a) Combustion chamber (b) L.P turbine (c) H.P turbine (d) Jet pipe 32. In a chromel Alumel thermocouple instrument shown (a) A is +ve and B is –ve (b) A is green and B is white (c) A is –ve and B I +ve 33. In the adjoining figure, why are the curves for real and ideal conditions different? (a) Since air is not treated as a compressed gas Surge Buzz Supersonic Positive incidence stall Rear stage stall at high speed Negative incidence stall front stage stall at high speed 34. Mark the correct statement (a) Whittle combustion chamber has low pressure loss (b) Annular combustion chamber has low smoke emission (c) Annular combustion has the most optimum utilization of space 35. Mark the correct statement regarding the cleaning of various engine sections (a) Hot section cleaning statement is done by (b) Cold section cleaning is done by vapour degreasing and (c) Trichloroethylene is not suitable for titanium (d) All are correct 58
36. Stagger angle is done for (a) Wide chord is done for efficiency (b) Mid span shroud is for stability (c) First stage fan blade is made from (i) Al alloy (ii) Titanium 37. Fire detectors Bimetallic (a) Thermocouple Capacitance
Thermistors Surveillance Dielectric Semi-conductors Infra-red rays
38. Fuel injector is made for Square law Crack pressure Inverted flow chamber Simplex Duplex vaporization Duplex Duplex Prevapourisation Simplex Simplex Duplex prevapourisation vaporization
Better pr. At low pr. Centrifugal
Pre-
Centrifugal Prevapourisation Centrifugal
Centrifugal Pre-
39. As per international standards organization the following symbols reveal Restrictor Heater Absolute Filter Cooler Gauge 40. Fuel scheduling input variable are N1 and TGT MEC Ratio unit Amplifier V.S.V Sensor less F.C.U. Secondary channel E.E.C. 41. Match the following (a) Back pressure valve Spray nozzle (b) L.P speed governor Fuel pump (c) Dash pot throttle Annulus (d) P.R.V F.C.U. Solenoid 42. Match the following High oil pressure blocked P & D Defective pump
Oil quantity increases at tank Breather pressure leak 59
Partially
Hot start
Seal is broken start
FCOC leak
Hung start/No
43. A gas turbine engine is revolving at max r.p.m. If Wa increases (a) C.P.R increases (b) C.P.R decreases P. t7 / P t2 (c) C.P.R. remains the same (d) None of the above 44. In Reheat, if the C.P.R. exceeds the limit then (a) Speed governor adjustment is required (b) Nozzle adjustment is required idle r.p.m. Adjustment is required (c) F.C.U adjustment is required 45. F.C.U is running at idle. If OAT increases idle r.p.m. is constant, it is due to (a) C.I.T adjustment Idle r.p.m = fn. (C.I.T.) (b) Defective throttle C.I.T. = fn. (OAT) (c) Speed sensor (d) C.D.P adjustment 46. If an engineer finds that the EGT reading is less than that of normal it may be dure (a) Faulty electrical harness (b) Wire length is shortened during maintenance 47. Jet engine noise (a) Compressor noise is less than jet – pipe noise (b) Low frequency decays more rapidly than high frequency noise (c) . (d) All are correct
48. An air leak is internally at fan duct in compressor aircraft (a) N1, N2 will increase (b) EGT will increase (c) Fuel flow will increase (d) All are correct 49. If an engine has been started using all components normal and hung start occurs, it may be due to (a) Closure of surge bleed valves (b) Opening of surge bleed valves (c) Lack of lubrication in the bearing 60
50. If the CSU (constant speed unit) fails, the pilot will maintain (a) At climb, the r.p.m. Is maintained at climb r.p.m. (b) At cruise, coarse pitch is constant (c) At climb, the pilot increase throttle to fly at level flight condition 51. A cascade varies type thrust reverse (a) Does not take cowl-load sharing 52. When an electronic TGT amplifier fluctuates (a) Amplification, TGT, N2 sensor all fluctuates 53. Starter has two holes (a) For alignment (b) For breather sump vent 54. Exhaust nozzle is changed due to heat after long operation. It will cause (a) The thrust to reduce for the amount of fuel flow (b) The thrust will increase with increase in EGT. (c) No appreciable change in thrust or EGT as area is the same (d) The thrust will increase due to increase of fuel flow due to more airflow through inlet 55. Mark the correct statement (a) Compressors are loaded more in the front stages (b) Compressors are loaded more in the rear stages 56. Bore scope inspection is does through the holes given. During inspection the HPT shaft is rotated (a) By removing the starter and rotate through the starter engagement gears (b) By a drive pad provided for this purpose in the AGB section of the engine (c) After removing the c/c only, B.S.L can be done (d) 7/8” socket and spanner attached in the hand cranking pad 57. If the adjustment of the P & D valve on the FCU is lower than normal then (a) Hot start (b) Hung start 58. After engine light up the state does not cut off. The probable cause is (a) Starter cut-off circuit is faulty 61
(b) Starter drive spring is weak (c) Starter bleed valve does not close (d) Either (a) or (b) is correct 59. Hot shift and cold shift of engine is determined by (a) C.I.T sensor probe condition (b) T.I.T sensor probe condition (c) T.L.A and its position w.r.t M.E.C (d) T.I.T sensor and C.I.T sensor condition 60. Engine anti-icing system condition and (a) Heats up fwd, and rearward simultaneously (b) Heats up fwd, and rearward in cyclic operation (c) Consists of dual butterfly valve, which regulates the hot bleed air in relation with a timer circuit (d) Can be used in both flight and ground operation 61. L.O.P light illuminates during flight, what are the other parameters (associated with the same) that the pilot has to check on the cockpit indicators? (a) EGT and r.p.m indicators for the engine malfunction (b) N1 r.p.m. Gauge and oil temperature (c) Filter clogging light and EGT (d) No indicators to check but to cut-off the engine. 62. In the inlet of the hydraulic pump is blocked, what will happen? (Check Feb. 96) 63. In the pressurized chamber of the bearing sump area overboard drain is provided. This prevents (a) Compressor air contamination (b) Inward air flow to the chamber (c) Oil tank overflow (d) None of the above 64. What does the graph indicate? (a) Compressor contamination (b) Undesirable engine condition (c) Normal condition (d) Engine due for overhaul 65. In a turbo shaft engine, the electric starter has carbon brushes, which are worn out. This will (a) Decrease the starting speed (b) Not start the engine 62
(c) Make EGT high (d) All are correct 66. A turbofan engine, with a hydro-mechanical FCU shows constantly poor r.p.m. Pick-up to maximum power. To detect the snag, mark the correct statement (a) C.D.P. sensor and N1 Cr (b) C.I.T. sensor and N2 Cr (c) R.p.m. sensor (d) Governor problem 67. The power turbine turbo-shaft is running at higher r.p.m. There is a loss of oil pressure. The most probable cause is (a) The relief valve stuck in closed position (b) The relief valve is jammed in open position (c) Filter clogged (d) Oil spray jet clogged 68. Which of the following condition, for long time storage of engine (a) Lip (b) Cup (c) Carbon-rubbing (d) All are correct 69. Engine operation inspection is O.K. except flame out during deceleration. The most likely cause is (a) Acceleration and deceleration valve (b) Minimum flow valve setting (c) Maximum flow valve setting (d) Governor setting (for maximum speed) 70. Match the following condition, for long time storage of engine (a) Intake (b) Fuel system (c) Compressor (d) Exhaust 71. Which is the hottest point in the engine? (a) Compressor casing (b) Combustion chamber casing (c) N.G.V casing (d) Jet pipe casing 72. If C.S.D fails during climb, (a) r.p.m. Remains the same 63
(b) Coarse pitch is selected (c) Throttle is to be adjusted for level flight conditions (d) All of the above 73. Partial clogging of P & D valve results in (a) Hot start (b) Hung start. 1. Electric motion generator starter used in get engines (a) Separate starter & generator not reqd (b) Common armature is used (c) Two field windings are used (d) All are correct 2. Air turbine starter used for get eng (a) Have light to torque ratio low (b) Reqd. supply of high vol of airflow (c) Both a & b are correct 3. In auto ign. System (a) Starter ents of automatically after eng attains self acc. Speed (b) It is designed primarily to ensure instant a NEOUS ign, if an eng., begins to loose pwr in air (c) Automatically restarts when flame out occurs (d) All are correct 4. MCS (a) The gap at igniter plug is such wider than that of spark plug (b) As in a tip of igniter plugs not permitted to clean (c) The ignition of gas turbine eng., is not continuous as used in piston eng (d) All are correct 5. The problem of droop in governor can be reduced by (a) Using weaker spring requiring lower force for valve movement (b) Making metering port narrow so that is requires small movement of the valve (c) Decrease the pr differential across the metering valve (d) All are correct 6. Amongst the many inputs to the fuel control it senses (a) N2 burner pr (b) As in a ITT, RPM (c) As in b CIP 64
(d) As in c CIP 7. HOT SECTION OF ENG. INGLUDE (a) Comp, turbine, combination (b) Combustion, turbine, exhaust (c) Comp, comb, exh, (d) None above 8. Which is not part of the eng (a) Main fuel pump (b) Fuel boost pump (c) Filter (d) All are correct 9. MCS regarding centrifugal comp (a) Pr. Rise per stage is high (b) Low frontal area (c) Possible damage to fod (d) All are correct 10. Lubrication oil use din gas turbine engine have (a) Low viscosity index (b) High viscosity index = low viscosity (c) High pour point (d) High viscosity 11. When water is injected in diffuser sec (a) N1 will shift towards stall (b) N2 will shift away from stall (c) N2 will shift towards stall (d) As a & c are correct 12. MCS (a) Pr pump is gear type scavenge pump is centrifugal type (b) Pr. Pump is venk type sev pump is gear type (c) Both of gear type (d) Pr. Pump is vent type & sev is vene type 13. Propeller blade tracking is the process of determining (a) The plane of rotation of propeller w.r.t. a/c longitudinal axis (b) That blade angle within the specified tolerance of each others (c) The position of tips of the prop. Blades relative to each other (d) All are correct 14. Angle of attack of blade is defined as 65
(a) Angle between airfoil section method line & plane of rotation (b) Angle between chord line & the relative change (c) Axis of blade rotation during pitch change 15. MCS (a) Geometric pitch is the distance a propeller should mores fwd in one complete rev., (b) Effective pitch is the actual distance a prop move fwd in one complete rev. (c) Slip is difference between geometric & effective pitch (d) All are correct 16. Reverse pitch prop (a) Uses far reducing landing roll (b) When used high fuel is consumed (c) All are correct 17. Compressor blades are attached to the rotor by (a) Fir tree with retention device (b) Dovetail slot (c) Bulb type (d) A & b are correct 18. Thermocouple type egt probes reconnected in (a) Fir tree with retention device (b) Dovetail slot (c) Bulb type (d) A & b are correct 19. Procedure of reconturing-damaged area of fan blades is called (a) Blending (b) Shaping (c) Burnishing (d) Blabbering 20. The temp of air is higher in rear stages of comp. This is due to (a) Diffusion action (b) Mechanical work. Done by rotor with an (c) Mechanical energy is converted into heat energy (d) All are correct 21. The type of eng. Used in helicopter is (a) Shaft (b) Prop (c) Fan 66
(d) As in a with free turbine 22. Inc., the exhaust nozzle area will result in (a) N2 dec (b) Thrust dec (c) N1 inc., (d) As in a with free turbine 23. Diffuser in centrifugal comp (a) Inc, static pr (b) Inc, velocity and pressure (c) Increases kinetic velocity and decreases pressures (d) Decreases velocity and pressure 24. In the compressor RPM engine speed remain constant and mass airflow increased (a) Pressure ratio will increase and stall margin will decrease (b) Pressure ratio will increase and stall margin will inc (c) Pr. Ratio & stall margin will dec (d) Ratio will dec & stall 25. TSFC change (a) Directly by thrust (b) Inversely by p. ratio (c) Directly by pr. ratio 26. MCS (a) Temp drop takes places thru the turbine i.e. approx equivalent to the temp rise occurred in the comp (b) Temp drop takes place than the turbine is much greater than the temp rise of the comp 27. Stall characteristic of comp. Blade (a) Begin to in., at higher altitude due to higher Reynolds no., & thus dec., efficiency of the eng. (b) Remains same on the ground & at higher altitude. 28. Components used in the secondary air thrust reverse type (a) Blocker door (b) As in A cascade vane (c) As in b translating sleeve (d) As in c thrust 29. In modern jet eng., fue metered fuel by 67
(a) Airflow may be metered by keeping the pr., drop across the metering valve constant while varying the valve orifice (b) Valve orifice may be kept constant size and the pressure difference varied (c) Varying bath (d) All are correct 30. A BURNER design, which reduces cooling air req. by 50% & dec., burner wt., by 20% is (a) Float wall (b) In wall (c) Annular (d) Reverse flow 31. During cruise (a) Igv & stator vanes in closed position (b) Igb & stator in fully open 32. Fire extingquishing agents (a) Freon (b) Methyl bromide (c) Cholorabromoethane (d) All are correct 33. When fire extinguishing agents introduced into the engine (a) Water & chloride mixture wash is necessary (b) Extinguishing agents will evaporate itself and no need of water wash (c) It is normal & no need of precaution (d) Shut do the eng & send it to the shop 34. Continuous loop fire detection system (a) Ceramic beads looses resistant after temp, rise & causes fire warning & require manual reset (b) The ceramic beads looses resistant after temp rise & give fire warning will automatically resets itself when cooled 35. MCS (a) In two wire thermal s/w type fire detection can withstand either an open or a short & still remain in function (b) In fenwal type also (c) A & B are correct 36. MCS (a) In nozzle diaphragm area is measured at the exit of the vanes 68
(b) Total area is sum of all areas between the vane (c) Nozzle area effects the efficiency of the eng (d) All are correct 37. MCS (a) Pr. Of supersonic air as it flows that the convergent nozzle inc (b) As in a pr. Of super sonic air is flows thru a convergent nozzle is inversely proportional to the temp (c) As in a the pr of supersonic air as it flows thru convergent nozzle is directly proportional to the temp. (d) The pt. of supersonic air is it flows thru convergent nozzle dec. 38. When a turbine stage is damaged will have (a) Vibration throughout the eng. But clearly at low speed. (b) Eng. Vibration through out pm range but indicated amplitude reduces as rpm reduces (c) Vibration through out the eng., but most probably at high speed & fuel flow (d) Eng. Vibrates through rpm range but is more prommcal in cruise or idle condition 39. Eng. Trumbles during starting at low power cruise condition the reason is (a) Pressuring & damp valve malfunction (b) Cracked an duct (c) Fuel control malfunction (d) All are correct 40. Fuel is delivered at high-pressure thru the fact control unit thru (a) Gear type pump (b) Centrifugal boost type (c) Gear type & centrifugal boost pump (d) Filter, gear type pump & centrifugal pump 41. Trimming of eng. Is necessary (a) After fen change (b) As in a to set maximum thrust (c) As in b to set idle rpm (d) All are correct 42. Water contain in fuel will (a) Clog the pump out let (b) Cause corrosion (c) Can cause engine performance loss or even lame out jeppesen 262 (d) All the above correct 69
43. Filter used in get eng. (a) Screer disk type steel insert filter (b) Water type (water, screen fuel filter) (bowl type filter) (c) Cartridge type filter (d) All the correct 44. Oil pt. indicator uses (a) Thermocouple (b) Resistance bulb (c) Auto sync system (d) Diaphragm repair of bellows 45. Egt indicator include (a) Red dial at max gas temp for wet & operation (b) Green arc from max permissible temp, for continuous operation to minimum recommended by the eng. Manufacture (c) Yellow / amber are from max temp for continuous operation to max permissible gas temp (d) All are correct 46. Vibration momtor (a) Latest type uses piezo electric type (b) As in a also uses velocity pickup 47. When an eng is operation without its antince valve on epr inc., when other parameters readings are normal the reason (a) Ice formed the inlet cowling causing low piston PIC probe parts act as PS2 (b) Causing high pr. On PT2 probe (c) Fuel malfunction (d) Rise is engine pr ratio indication in cockpit 48. Motor less type fuel flow meter senses fuel by (a) Vane moves against mass flow (b) Two signals through transducers (c) Impeller & synchronous unit 49. P & D valve acts as a (a) Flow divider 50. Provision for drain of fuel in eng. (a) Feoe have provision for slight Crain if requd (b) Fuel heater will have provision for same drain of fuel (c) Combustion chamber have provision for drain 70
51. Wet thrust means (a) Max power available when water is injected SEMESTER EXAMINATION JET ENGINES – THEORY AND CONSTRUCTION Part – I QUIZ TYPE 1. Which of the following is not an air-breathing engine? (a) Rocket (b) Piston (c) Ramjet (d) Turbofan engines 2. The general method of attaching compressor blades is (a) By fixture arrangement and locking (b) By dovetail arrangement and locking (c) By welding to the disc (d) Both B & C are correct 3. The basic types of turbine blades are (a) Reaction and converging (b) Tangential and converging (c) Reaction and impulse (d) Impulse and vector 4. The advantages with split spool compressor over single spool compressor is (a) Better compression ratio and surge margin (b) More turbine wheels can be used (c) The velocity of air entering the combustion chamber is increased (d) Number of bearings required is reduced 5. To produces a thrust of 9600 lbs a jet engine consumes 900 gallons of fuel per hour. Given that one gallons of fuel weighs 8 lbs. What is the thrust specific fuel consumption of the engine? (a) 0.075 lbs/hr/lb thrust (b) 0.750 lbs/hr/lb thrust (c) 1.330 lbs/hr/lb thrust (d) None of the above 6. Compressor blades are not rigidly fixed but a slight movement is allowed in order to 71
(a) Provide flexibility for blade replacement (b) Provide tolerance for blade expansion (c) Reduce vibration stresses produced by high velocity air stream (d) All the above 7. Turbine blades creep with increase is temperature and operating time. This means (a) The blades elongates (b) Blade wears out (c) The blade losses its toughness (d) All the above 8. Which of the following engine casing is the hottest during engine run (a) H.P turbine casing (b) L.P turbine casing (c) Jet pipe (d) Combustion chamber casing 9. What is the primary advantage of an axial flow compressor over a centrifugal flow unit? (a) Easier maintenance (b) High frontal area (c) Less expensive (d) Greater pressure ratio 10. The compression ratio of an axial flow compressor is a function of (a) The No. Of compressor stages (b) Rotor diameter (c) Diffuser area (d) Air inlet velocity 11. Which of the following types of combustion sections are used in aircraft turbine engines. (a) Variable can annular and cascade vanes (b) Annular variable and cascade vane (c) Can multiple can and variable (d) Multiple can, can annular, and annular. 12.The exhaust section of a turbine engine is designed to (a) Impart a high exit velocity to the exhaust gases (b) Swirl the exhaust gases (c) Increases temperature there by increasing velocity (d) Decreases temperature there by increasing pressure
72
13. Why do some turbine engines have more than one turbine wheel attached to a single shaft? (a) To facilitate balancing of the turbine assembly (b) To straightened the airflow before it entered the exhaust area (c) To help stabilize the pressure between the compressor and the turbine (d) Decrease temperature there by increasing pressure 14. What is the purpose of directing bleed air to the bearing compartment? (a) It increases oil pressure for better lubrication (b) It provides a high volume of oil to the most critical bearings (c) It heats the oil to the proper operating temperature (d) It heats the oil to the bearing compartments. 15. Which of the following variables affect the inlet air density of a turbine engine? (a) The turbine inlet temperature (b) The altitude of the aircraft (c) Compression ratio (d) The turbine and compressor efficiency 16. Dirt particles in the air being introduced into the compressor of a turbine engine will form a coating on all but which of the following (a) Turbine blades (b) Compressor blades (c) Casings (d) Inlet guide vanes 17. Mark the correct statements (a) Roller bearings take both axial and radial loads (b) Ball bearings take both axial and radial loads (c) Given the same diameter, the ball bearing takes greater load than the roller bearings (d) None of the above statement is correct 18. In the twins spool compressor system the first stage turbine drives the (a) N – 1 compressor (b) N – 2 compressor (c) N – 1 & compressor (d) The fan. 19. What are the two functional elements in a centrifugal compressor? (a) Bucket and expander (b) Impeller and diffuser 73
(c) Turbine and compressor (d) Air intake and expeller 20. Newton’s first law of motion states (a) To every action there is an equal and opposites re action (b) Force is proportional to the product of mass and acceleration (c) Every body persists in its product of mass and acceleration (d) Heat energy and mechanical energy are quantitatively inlet convertible 21. Engine pressure ratio for power assessment is determined by (a) Multiplying the engine inlet total pressure by turbine out let total pressure (b) Dividing turbine outlet total pressure by engine inlet total pressure (c) Dividing engine inlet total pressure by turbine outlet total pressure (d) Dividing compressor delivery pressure by engine inlet pressure 22. An advantages of the centrifugal flow compressor is its high (a) Ram efficiency (b) Peak efficiency (c) Pressure rise per stage (d) Frontal area 23. In a gas turbine engine combustion occurs at a constant (a) Velocity (b) Pressure (c) Density (d) Volume 24. Purpose of the stator vanes in an axial flow compressor is to (a) Increase the velocity of airflow and prevent swirling (b) Straighten the airflow and eliminate turbulence (c) Decrease the velocity prevent swirling and boost the pressure (d) Prevent compressor stalls and eliminate surge 25. In a turbine engine with a dual spool compressor the low speed compressor (a) Always turns at the same speed compressor, the low speed compressor (b) Is connected to the high-pressure compressor through a reduction gear. (c) Seeks its own best operating speed (d) Is coupled to the high-speed turbine mechanically but through a reduction gear. 74
26. How many ignitions are normally used on a turbine engine having nine burner cans? (a) One (b) Two (c) Nine (d) Eighteen 27. Using standard atmospheric conditions the standard sea level temperature is (a) 15 degrees C (b) 0 degrees F (c) 0 degrees C (d) 273 degrees K 28. Which of the following is the ultimate limiting factor of turbine engine operation? (a) Compressor inlet air temperature (b) Compressor outlet air temperature (c) Burner can pressure (d) Turbine inlet temperature 29. Where is the highest gas pressure in a turbo jet engine experienced? (a) At the outlet of the burner section (b) At the entrance of the turbine section (c) At the outlet of the tail pipe sections 30. What turbine engine sections provides for proper mixing of the fuel and air? (a) Combustion section (b) Turbine sections (c) Diffuser sections (d) Compressor sections
GAS TURBINE ENGINES – MODEL PAPER NOTE: 1. Answer the questions by circling the right answer 2. Answer the essay questions on the separate sheets provided 3. Write your name on the top R.H corner 75
PART I – QUIZ TYPE: 1. Both temps. And pr. Rise during combustion in (a) The Brayton cycle (b) The otto cycle (c) The otto brayton cycle (d) None of the above is correct 2. If the Pt2 probe is famed in a jet engine due to lee formation? (a) ETR will show high (b) EPR will show low (c) EPR will not be affect (d) EGT will go high 3. What is the basic function of combustion chamber is a gas engine? (a) Change potential energy of high speed air into ram pr (b) Change kinetic energy of air into pr. Energy (c) Reduce the speed of air and increase the volume of air and accelerate it (d) Change the thermal energy to potential energy 4. Which statement is true regarding jet engines? (a) At the lower engine speeds thrust increases rapidly with small increases in r.p.m. (b) At the higher engine speeds thrust increases rapidly with small increases in r.p.m. (c) The thrust delivered per found of air consumed is less at high delivered per pound of low altitude (d) The thrust delivered for a given small increase in r.p.m. is independent of the speed range at which rpm is increased 5. Using standard atmospheric conditions, the standard sea level temperature is (a) 590C (b) 590 F (c) 290 C (d) 00 C 8. ATA system specification 80-00-00 represents the chapter (a) Engine oil system (b) Ignition system (c) Engine starting system (d) Engine instrument system
76
9. The area of the after turner jet pipe is forger than normal jet pipe in order to (a) Reduce air velocity (b) As in A for better combustion (c) To prevent ckoking (d) None of the above 10. The exhaust system components are (a) Manufactured from nickel or titanium for high strength (b) Made from nickel or titanium for high strength (c) Made from high carbon steel for strength (d) None of the above statements is correct 11. Mark the correct statement w.r.t the by pass engine (a) The low by pass engine, the bypass ad core airflows are combined in a mixture unit before exiting through the propelling nozzle (b) In a high by pass engine. The by pass and core flows a reduction separately (c) The lower the by pass the higher the propeller of (d) All three statement are wrong 12. A variable area propeller nozzle: (a) Generally on engine without reheat because performance gain is offset by increase in weight (b) Gives better fuel economy during reheat application (c) Uses lower nozzle area during take off for greater (d) It used on high by pass engines for better fuel economy 13. What is the purpose of directing bleed air to the bearing compartment? (a) It seals the oil in the bearing compartment (b) It seats the oil to the proper operating temperature (c) It provides a high volume of oil to the most critical bearings (d) It increase the oil pr for better lubrication 14. It the water injection system operation the addition of methanol will (a) Restore turbine inlet temperature (b) Bringdown N2 rpm (c) Lower freezing point of water (d) Both a and c are correct 15. Mark the correct statement regarding thrust resources (a) Mixed exhaust type engines need only one resources (b) In high by pass turbo fans, recourse of secondary air is more effective than that of primary air 77
(c) Both primary and secondary how are reversed by using separate reverses (d) All of the above statements are correct 16. Rotation pad on the accessory G.B is provided for (a) Filtering alternate tacho-generator (b) For N2 rotation (c) To facilitate fan balancing (d) All the above statements are correct 17. In the APU (a) Turbine blades are made of titanium (b) APU has reverse flow combustion chamber (c) It is supported by plain journal bearing in the front and roller bearing at the rear (d) One of the above statement is correct 18. Power point is expressed in (a) Decibel – sound (b) Centistroke (c) Poise (d) Degree F 19. Anti icing of jet engine air inlets is commonly accomplishedly (a) Electrical heating elements inside the inlet guide vane (b) Engine blud air ducted through critical areas (c) Electrical heating elements located, within the engine air inlet cowling (d) Spent exhaust gas ducted through critical areas 20. The fire detection system that uses a single course surrounded by a temperature sensitive insulating medium in a tube is (a) Fenwal system (b) Kiddie system (c) Thermocouple system (d) Squists system 21. Which of these characteristics is desirable in turbine engine oil (a) Low flash point (b) High flash point (c) High volatility (d) Low viscosity index 22. Thrust reverse utilizing a pneumatic actuating system usually receive air from 78
(a) The engine bleed air system (b) An on board reciprocating compressor (c) One or more high pressure air battles (d) Environmental control system. 23. The rearward thrust capacity of an engine with the thrust reverse system deployed is (a) Less tharits forward capacity (b) Equal to or less than its forward capacity depending on ambient conditions and system design (c) Equal to its forward capacity (d) More than its forward thrust capacity since engine bleeds are kept closed 24. What is the function of an engine fire detection system? (a) To discharge the powerplane fire extinguishing agent at the origin of the fire (b) To activate a warning device in the event of a power plant fire (c) To identify the location of a power plant ifre (d) To idienfy the extinguisher son that spot 25. Mark the correct statement as applicable to magnetic plugs (a) They are removed at periodic intervals for condition monitoring (b) They are connected to a cock pit warming system to give an in flight indication (c) All the above statements are correct 26. Squeeze rpm type bearings are used on some engine to (a) Reduce vibration level of engine (b) Modify the radial motion of rotating assembly (c) Reduce possibility of damage by fatigue (d) Contribute to all the above 27. Mark the correct statement regarding T.R operation (a) T.R. can be used in the air to change direction of a/c heading (b) T.R is to be actuated at a height of 100 before a/c touch down for minimum use of run way (c) The T.R should be held in reverse till the a/c comes to a complete halt (d) None of the above statements is correct 28. The air and oil are separated in a jet engine oil system by returning the scavenge oil to (a) The bottom of the reservoirs (b) The deairator at the top of the reservor temp 79
(c) The pressurized tank (d) To the centrifugal separator 29. The net reverse thrust available on a high by pass engine having only tan revouser is approximately (a) 40 % (b) 80% (c) 60% (d) 100% 30. In a jet engine otherwise behaving normally there are reports of flameout during descent the problem is (a) Metering orifice in FCU clogged (b) Minimum flow valve malfunction (c) Fan exit guide vane icing (d) Malfunction of acceleration and deceleration valve 31. On a jet engine the EGT reading is high as noticed by he AME during comparison check in transit. The cause could be (a) Party compressor blades (b) One of the thermocouple probes is open circuit (c) Turbine blade rub at periphery (d) Both A & C are correct 32. In and engine with hydro mechanical system F.C.U pilot reports engine acceleration without throttle movement the possible cause is (a) Loss of spad sense (b) Loss of CDP sense (c) C.I.T sensor failure (d) Any one of the above 33. Compressor air leakage in a turbo fan engine is noted by (a) Rise in r.p.m (b) Rise in vibration (c) Rise in EGT (d) All the above 34. Engine hot start is indicated by (a) EPR increase (b) EPR increase (c) Fuel flow increase (d) Faster rise in EGT in proportion to N2 rotor rpm increase 35. If the crack pressure adjustment of the pressuring valve is on the lower ride that required than 80
(a) Secondary fuel will flow carlier (b) Start EGT will be higher (c) Stall margin will be reduced (d) All above is correct 36. What is the possible cause when a turbojet engine indicates no change in power setting parameters lent oil temperature is high (a) Gear box real leakage (b) Engine main bearing distress (c) High oil sump pressure (d) Oil scavenge pump not effective 37. Mark the incorrect match (a) Turbo prop Best TSFC (b) Turbo jet Best thrust to weight ratio (c) Rocket maximum air consumption (d) High by pass jet least noise 38. Why is the necessary to control acceleration and deceleration rates of turbine engines (a) To prevent blow out due to rich (b) To enable to heat and cool the engine at controlled rates (c) To prevent friction between turbine wheels and the case due to expansion and contraction (d) To operate engine at optimum fuel consumption 39. When the pilot selects water injection during take of which of the following observation is true? (a) The engine r.p.m rises (b) The engine r.p.m. Rises and J.P.T gas slightly above acceptable limit (c) J.P.T increases (d) Fuel consumption becomes less that normal due to water addition 40. Turbine blades air more susceptible to operation damage than compressor blades because of (a) Higher centrifugal loading (b) Exposure to high temperature (c) High pressure and high velocity gas flow (d) All the above 41. What is the first engine instrument indicating successful start of a turbine engine? (a) L.P.S spool rotation (b) Rise in exhaust gas temperature 81
(c) Rise in oil pressure (d) Rise in engine fuel flow 42. Hot section inspection for many modern turbine engines are required (a) Only at engine overhaul (b) Only when an over temperature or speed is reported (c) On a time or cycle basis (d) During every C of A renewal
SEMESTER IV 1. A severs condition of chafing or fretting in which a transfer of meal from one part to another occurs. If called (a) Gouging (b) Burning (c) Erosion (d) Galling 2. Compressor stall is caused by (a) A low angle of attack airflow through the first states of compression (b) A high angle of attack airflow through the first stages of compression (c) A high velocity airflow in the engine inlet (d) Rapid engine deceleration 3. Hot spots in the combustion section of a turbojet engine are possible indicator of (a) Foreign object damage (b) Faulty igniter plugs (c) Dirty compressor blades (d) Malfunctioning fuel nozzles 4. In what section of turbojet engine is the jet nozzle located? (a) Combustion (b) Turbine (c) Compressor (d) Exhaust 5. What is the purpose of the pressurization and dump valve used on turbo jet engine? 82
(a) Controls the pressure of the compressor outlet by dumping air when pressure reaches an established level. (b) Allows fuel pressurization of the engine when starting and operating and dumps fuel pressure of engine shutdown (c) Controls compressor stall by dumping compressor air under certain condition (d) Maintain fuel pressure to the fuel control valve and dumps excessive fuel bake to the fuel tanks 6. What is meant by a shrouded turbine? (a) The turbine blades are shaped so that their ends form a band or shroud (b) Each turbine wheel is enclosed by a separate housing or shroud (c) The turbine wheel is enclosed by a protective shroud to contain the blades in case of failure (d) The turbine wheel has shroud or duct which provides cooling air to the turbine blades 7. Why does a turbine engine require a cool off period before shutting it down? (a) To allow the surfaces contacted by the lubricating oil to return to normal operating temp (b) To burn off excess fuel ahead of the fuel control (c) To allow the turbine wheel to cool before the case contracts around I (d) To avoid seizure of the engine bearings 8. Which of the following types of combustion sections are used in a/c turbine engines (a) Variable, can-annular, and cascade vane (b) Annular, variable and cascade vane (c) Can multiple can, and variable (d) Multiple can, annular, and can annular 9. Why do some turbine engines have more than one turbine wheel attached to a single craft? (a) To facilities balancing of the turbine assembly (b) To straighten the airflow before it enters the exhaust area (c) To help stabilize the pressure between the compressor and the turbine (d) To extract more power from the exhaust gases than a single wheel can absorb 10. The compression ratio of an axial flow compressor is a function of the (a) Number of compressor stages 83
(b) Rotor diameter (c) Diffuser area (d) Air inlet velocity 11. What is the function of a fire detection system? (a) To discharge the power plant fire extinguishing system at the origin of the fire (b) To warn of the presence of fire in the rear section of the power plant (c) To activate a warning devices in the event of a power plant fire (d) To identify the location of a power plant fire 12. How does carbon dioxide extinguish and engine fire? (a) A continuous loop fire detector is what type of detector (b) By lowering the temp to a point where combustion will not take places (c) The gas spray liquefies in the heat and smoothers the fire (d) The high-pressure spray lowers the temperature and blows out the fires. 13. A continuous loop fire detector is what type of detector? (a) Spot detector (b) Overheat detector (c) Rate of temp rise detector (d) Radiation sensing detection 14. What is the operating principle of the spot detector sensor in a fire detection system? (a) Resistant core material that prevents current flow at normal temp (b) Fuse material that melts at high temp (c) A conventional thermocouple that produces current flow (d) A bimetallic thermo switch that closes when heated to a high temp. 15. Which of the following is the safest fire-extinguishing agent to use from a standpoint of toxicity and corrosion hazards? (a) Cholorbromomathane (Halon 1011) (b) Dibromodifluoromethane (Halon 1202) (c) Bromochlorodifluromomethane (Halon 1211) (d) Bromotrifluromomethane (Halon 1211) 16. Which of the following is not used to detect fires in reciprocating engine necellers? (a) Smoke detectors (b) Overheat detectors 84
(c) Rate of temp rise detectors (d) Flame detectors 17.What is the principle of operation of the continuous loop fire detector system sensor? (a) Fuse material which melts at high temp (b) Core resistance material which prevents current flow at normal temp (c) A conventional thermocouple which produces a current flow (d) A bimetallic thermo switch which closes when heated to a high temp 18. Why does the fenwal fire detection system use spot detectors wired in parallel between two separate circuits? (a) A control unit is used to isolate the bad system in case of malfunction (b) This installation is equal to two systems a prime system and a reserve system (c) The duel terminal thermo switch is used so that one terminal is wired to a bell the other to a light (d) A short may exist in either circuit without causing a false fire warning. 19. Which of the following fire detector system measures temp rise compared to a reference temp? (a) Fenwal continuous loop (b) Thermocouple (c) Thermal switch (d) Lindberg continuous element 20. A fuel or oil fire is defined as a (a) Class B fire (b) Class D fire (c) Class A fire (d) Class C fire 21. When starting a turbojet engine (a) A hot start is indicated if the exhaust gas temperature exceeds specified limit (b) An excessively lean mixture is likely to cause a hot start (c) The engine should start between 60 to 80 seconds after the fuel shut off lever is opened (d) Release the starter switch as soon as indication of light off occurs
85
22. In the dual axial flow or twin spool compressor system the first stage turbine drives the (a) N1 and N2 compressors (b) N4 compressor (c) N2 compressor (d) N1 compressor 23. Cracks may occur in hot section components of a turbine engine if they are marked during inspection with (a) A lead pencil (b) Chalk (c) Layout dye (d) Any of the above 24. When starting a turbine engine, a hung start is indicated if the engine. (a) Exhaust gas temperature exceeds specified limits (b) Falls to reach idle RPM (c) RPM exceeds specified operating speed (d) Pressure ratio exceeds specified operating limits 25. What are the two main sections of a turbine engine for inspection purposes? (a) Combustion and exhaust (b) Hot and cold (c) Compressor and turbine (d) Combustion and turbine 26. What are the two functions elements in a centrifugal compressor? (a) Turbine and compressor (b) Compressor and manifold (c) Bucket and expander (d) Impeller and diffuser 27. What must be done after the fuel control unit has been replaced on a turbine engine? (a) Retime engine (b) Recalibrate the fuel nozzles (c) Retrim the engine (d) Recheck the flame pattern 28. What is the most satisfactory method of attaching turbine blades to turbine wheels? (a) The fire-tree design (b) The tongue and groove design (c) High temp high strength design 86
(d) Press fit method 29. A turbine engine compressor which contains vanes on both sides of the impeller is a (a) Single entry centrifugal compressor (b) Double entry centrifugal compressor (c) Double entry axial flow compressor (d) Single entry axial flow compressor 30. What is the first engine instrument indication of successful start of a turbine engine? (a) A decrease in the exhaust gas temperature (b) A rise in the engine fuel flow (c) A decrease in the engine pressure ratio (d) A rise in the exhaust gas temperature 31. Fuel before entering kinto fcu it encounter a course filter (a) The course filter protects metering section against damage by contamination (b) This filter has by pass provision and permit continued operation with unfiltered fuel (c) This filter is self cleaning type 32. During boroscope inspection (a) Engine should be cold (b) All boroscope plug on the engine should be in failed back in same place after completion of job (c) Engine should be rotated thro N2 pad (d) All above to be done 33. Engine fail to start to restart engine (a) Recycle the fuel shut off lever to restart (b) Shut off fuel and ignition and dry motor engine for 15 sec before attempting to restart (c) Engine start again after 30 sec (d) Starter must be replaced 34. During starting if engine over temp beyond specified limit. (a) Engine should be cooled down and restarted (b) Engine compressor boroscope to be done before starting (c) Immediately shut down engine and determine cause of over temp (d) Carry out in situ hot section inspection and find out cause of over temp before attempting to restart
87
35. Anti static leak valve provided in some lubricating system in turbine engine (a) To maintain pressure in oil system (b) To maintain oil line full (c) To help cold starting of engine (d) To prevent flooding of gear box after engine shut down 36. Starting egt high on turbine engine (a) Idle mixture lean (b) Ambient temp low (c) VSV rigging not correct (d) Weak spark on igniter 37. Reciprocating engine fuel injection carburetor not developing full power may be due to (a) Propeller balancing out (b) Carburetor idle RPM adjustment not correct (c) AMC defective (d) Cylinder head cooling fin cracked 38. On turbine engine cruise egt high (a) Flt idle RPM high (b) Incorrect throttle riging (c) Inter stage bleed valve stuck open (d) Fuel temperature high 39. Carburetor mounting bolt loose flange crack (a) Will cause rich mixture tall (b) Acceleration poor (c) Overheating of cylinder and power hors (d) Engine will not start 40. Reciprocating engine is shut down by (a) By putting fuel shut off valve to off position (b) By putting ignition s/w to OFF position (c) By putting mixture controls lever to idle cut of position (d) None of the above 41. What are the self-igniting temperatures of kerosene? (a) 6500 C (b) 7500 C (c) 4280 C (d) 8500 C 42. Specific fuel consumption is checked during 88
(a) Take off (b) Climb (c) Cruise (d) Landing 43. Calorific valve is measured (a) In horse power (b) BTU/IB (c) Lbs /Gallon 44. While rigging power lever one important to check is conditioning (a) If out of limit engine will have rich due out (b) If limit of cushion is within limit internal stop will not allow to over boast engine (c) Cushion of power lever assure that will not only be able to obtain take off power but also additional power lever movement during emergency (d) Cushion of power lever is given to have smooth and free operation and to get maximum power. 45. The active clearance control portion of an eec system aid turbine engine efficiency by (a) Adjusting start vane position according to operating condition and power requirement (b) Ensuring compressor and turbine blade to the engine laseing clearance are kept a minimum by controlling case temperature (c) Automatically adjusting engine spaced to maintained a desire EPR 46. Fuel flow indicator needle is inter by (a) A mechanical gear train (b) Direct coupling to motor shaft (c) Magnetic linkage (d) A friction clutch on motor shaft 47. Combustion efficiency of jet engine is primary function (a) Chemical composition of fuel (b) Combustion chember designs (c) Viscosity of fuel (d) Flame speed 48. Oil pressure gauge oscilate constantly (a) Leaking oil per line (b) Dirty filter (c) Indication needle loose (d) Reducer in oil line to indicator partially clogged 89
49. Which of the following turbine fuel filters has greatest filtering action action (a) Micron (b) Wine mesh (c) Wafer seneen (d) Stack charcoal 50. What should be checked/changed to ensure the validity of turbine engine perfomance check of alternate fuel is used? (a) Fuel sp gravity adjustment (b) Maximum RPM adjustment (c) EPR KG gauge calibration (d) 51. MIL F- 4624A. ATF – JP – 4 Fuel commonly used on gas turbine engine because (a) High calorific value of fuel (b) Specific gravity and vapour pressure low (c) Good lubrication properties (d) All above 52. Which type of fuel control is used on most turbine engine? (a) Mechanical (b) Hydro mechanical (c) Electronic (d) Electromechanical 53. What are the main input parameters in fuel controller unit monitors fuel flow (a) Compressor inlet pressure compressor RPM and turbine inlet pressure (b) Compressor inlet pressure compressor RPM compressor pressure ratio (c) Compressor inlet temperature burner pressure, tail pipe temperature (d) Compressor inlet pressure, burner pressure and compressor RPM 54. Which type of engine driven fuel pump are mostly used on turbine engine (a) Vane tyupe (b) Double gear element (Series) (c) Centrifugal pump (d) Double gear element (parallel) 90
55. Which component in FCU prevent compressor stall during acceleration (a) Compressor inlet temperature sensor and turbine inlet temperature sensor (b) By adjusting high differential pressure across throttle valve (c) By adjusting forward thrust stop and idle RPM (d) By a mase stop positioned by three dimensional cam which is rotated by signal proportional to engine speed and translated by signal proportional to CIP 56. What are the positions of pressurizing and dump valve when engine is shut down? (a) Pressurization valve and dump valve open (b) Pressurization valve closed and dump open (c) Pressurization valve open and dump closed (d) Pressurization valve closed and dump closed 57.Where flows divider is located (a) In simplase fuel nozzle (b) In the fuel manifold (c) Near pressurizing and dump valve (d) In duplex fuel nozzle 58. What are the causes of hung start? (a) HP fuel shut off valve defective (b) Defective compressor inlet pressure sensor (c) Burner pressure line leaking or cracked (d) Above all (e) 59. What are the causes of start exhaust gas temperature high? (a) Fuel pump boost stage failure (b) Compressor pressure ratio prob defective (c) Start fuel flow high (d) Variable stator vane stuck open 60. Under which of following conditions will be trimming of turbine engine will be most accurate? (a) Low moisture and tail wind (b) Aircraft should be parked in cross wind and high humidity (c) All fuel tank must be full and rear cargo ballasted (d) Aircraft parked engine facing wind and after engine warmed go stabilize temperature 61. What term is used to describe a permanent and cumulative deformation of the turbine blades of turbojet engine? (a) Stretch 91
(b) Elongation (c) Distortion (d) Creep 62. Which of the following can cause fan blade shingling in a turbofan engine? (a) Engine over speed (b) Engine over temperature (c) Large rapid throttle (d) FOD 63. Compressor stall is caused by (a) A low angle of attack airflow through the first stages of compression (b) A high angle of airflow in the through the first stages of compression (c) A high velocity airflow in the engine inlet (d) Rapid engine deceleration 64. A condition known as hot streaking in turbine engine is caused by (a) A partially clogged fuel nozzle (b) Misaligned combustion liner (c) Uneven burner can cooling (d) Excessive fuel flow 65. How many igniter are normally used on a turbine engine having burner cans? (a) One (b) Two (c) Three (d) Nine 66. Which of the following is used to minotor the mechanical integrity of the turbines as well as to check engine operating conditions of a turbojet engine? (a) Engine oil pressure (b) Engine gas temperature (c) Engine oil temperature (d) Engine pressure ratio 67. Which of the following can inspect and approve an engine major repair for return to service? (a) Certificated mechanic with airframe and power plant ratings (b) Certificated mechanic with a power plant ratings (c) Certificated mechanic with inspection authorization 92
(d) Designed mechanic examiner 68. Hot spots in the combustion section of a turbojet engine are possible indicators of (a) Foreign object damage (b) Faulty igniter plugs (c) Dirty compressor blades (d) Malfunctioning fuel nozzles 69. The fuel flow in the combustion section of a turbojet engine are possible indicators of (a) Fuel mass-flow (b) Fuel volume flow (c) Engine burner pressure drop (d) Fuel viscosity flow 70. Which of the following conditions is usually not acceptable to any extent in turbine blades? (a) Cracks (b) Nicks (c) Pits (d) Dents 71. Which of the following I the ultimate limiting factor of turbojet engine operation? (a) Compressor inlet air temperature (b) Compressor outlet air temperature (c) Turbine inlet temperature (d) Burner can pressure 72. The oil used in reciprocating engine has a relatively high viscosity due to (a) The reduced ability of thin oils to maintain adequate film strength at altitude (reduced atmosphere pressure) (b) The relatively high rotational speeds (c) Its lower oxidation rate at elevated temperature (d) Large clearances and high operating temperature 73. The type of lubricating oil that is used in a turbine aircraft engine is (a) Synthetic (b) Petroleum (c) 50-50 blend of petroleum and synthetic (d) 30-70 blend of petroleum and synthetic 74. The viscosity of a liquid is a measure of its 93
(a) Resistance of flow (b) Rate of change of internal friction with change in temp density (c) Density (d) Ability to transmit force 75. In a reciprocating engine oil system, the temperature bulb senses oil temp (a) And indicates the average oil temp (b) At point after the oil has passed through the oil cooler (c) While the oil is in the hottest area of the engine (d) Immediately before the oil enters the oil cooler 76. What is the purpose of an augmenter used in some reciprocating engine exhaust systems? (a) To reduce exhaust back pressure (b) To aid cooling the engine (c) To assist in displacing the exhaust gases (d) To augment the surface area of the exhaust extension 77. How do cowl flaps aid in cooling a horizontally opposed aircraft engine? (a) Furnishes ram air to the engine cylinders (b) Directs air through the engine cylinders (c) Stremlines the engine (d) Controls the amount of air passing around the engine 78. Power recovery turbine used on some reciprocating engine are driven by the (a) Exhaust gas pressure (b) Crankshaft (c) Velocity of the exhaust gases (d) Fluid drive coupling 79. A bend colling fin on an aluminium cylinder head (a) Will cause rejection of the cylinder (b) Should be sawed off and filed smooth (c) Should be left alone if no crack has formed (d) Should be stop drilled or a small radius filed at the point of the bend 80. If the turbo supercharger waste gate is completely closed (a) None of the exhaust gases are directed through the turbine (b) The manifold pressure will be lower than normal (c) The turbo supercharger is in the OFF position (d) All the exhaust gases are directed through the turbine 94
81. How do the turbines, which are driven by the exhaust gases of a turbine compound engine, contribute to total engine power output? (a) By driving the crankshaft through suitable couplings (b) By causing the exhaust back pressure to remain below atmosphere pressure at all operating altitudes (c) By driving the supercharger thus relieving the engine of the super charging loud (d) By converting the latent heat energy of the exhaust gases into thrust by collecting and accelerating them 82. Corrosive valve clearance results in the valves opening (a) Early and closing early (b) Late and closing early (c) Early and closing late (d) Late and closing late 83. Metallic particles are found on the oil screen during an engine inspection (a) It is an indication of normal engine wears unless the particles are nonferrous (b) The cause should be identified and corrected before the aircraft is released for flight (c) It is an indication of normal engine wear unless the deposit. Exceeds a specified amount (d) It is an indication of normal engine wear unless the particles show ferritic content (respond to a magnet) 84. Excessive valve clearance will cause the duration of valve opening to (a) Increase for both intake and exhaust valves (b) Decreases for both intake and exhaust valves (c) Decreases for intake valves and increases for exhaust valves (d) Increases for intake valves and decreases for exhaust valves 85. Engine operating flexibility is the ability of the engine to (a) Deliver maximum horsepower at a specific altitude (b) Meet exacting requirement of efficiency and low weight per horsepower ratio (c) Run smoothly and give the desired performance at all speeds (d) Expand and contract with changes in temperature and pressure 86. What is an advantages of using metallic fillex exhaust valves in aircraft reciprocating engine? (a) Increased resistance to corrosive gases (b) Increased strength and resistance to fatigue 95
(c) Reduced valve operating temperature (d) Greater resistance to deterioration at high valve temperature 87. Excessive valve clearance in a piston engine (a) Increases valve overlap (b) Has no effect on valve overlap (c) Increases valve service life (d) Decreases valve overlap 88. The pumping capacity of the scavenger pump in a dry-sump aircraft engine’s lubrication system? (a) Is greater than the capacity of the oil supply pump (b) Is less than the capacity of the oil supply pump (c) Is usually equal to the capacity of the oil supply pump in order (d) Varies according to the oil supply tank capacity and not according to the oil supply pump capacitys 89. The economizer system of a float type carburetor performs which of the following functions? (a) It supplies and regulates the fuel required for all engine speeds below cruising (b) It supplies and regulates the fuel required for all engine speeds (c) It supplies sand regulates the additional fuel required for all speed above cruising (d) It regulates the fuel required for all engine speeds and all altitude.
JET ENGINE (JUNE 96) 1. Fig. Shown trend analysis the defect indicated is 96
(a) N2 indicator defective (b) Bleed valve struck in open (c) Bleed valve struck in close (d) All are wrong 2. In a turbo prop engine for a given EPR (a) EGT rings with altitude (b) EGP decreased with altitudes (c) Altitude has no effect on EGT (d) All are correct 3. Fig. Shown a simple torque meter which in the torque sensing component (a) A (b) A B & C (c) B & C (d) E 4. Axial compressor the blades becomes shorter at the rear stages (a) To increases the velocity of air (b) To prevent high speed stall and surge 5. CSD input RPM is 5800 while output RPM in 6000 (generator) the CSD is working as (a) Hyd. Motor (b) Pump (c) Direct straight drive to generator is working as 6. NTCS regarding the r-v graph (a) Stage between 1 & 2 is compression (b) Stage between 2 & 3 is compression (c) Stage between 3 & 4 is compression (d) All of the above are correct 7. The fig shown a thermocouple probo MTCS (a) A is eve (b) A is alumal and is color codeddgraph (c) A a thuds magnet (d) All above are correct 8. A helicopter on rescue mission is hovering. The EGT is 7000 C when the power is increased (a) EGT will increased (b) EGT will decreased (c) EGT will first decreased upto certain power and train increases 97
9. A turbo shaft produces max. power (a) At take off (b) At minimum contingency (c) At max. contingency (d) Max continuous 10. A turboshaft produces max power (a) Below PSI (b) Above 20 PSI (c) Between 10 – 18 PSI (d) None 11. Most commonly used cleaning agent for turbine blades (a) Kerosene (b) Telchoroethylene eloctrolyto (c) Any one can be used 12. Turbine engine components are never manufactured by (a) Argon or plasma are welding (b) Gas welding (c) Elec resistance welding 13. MTCS regarding the goar type pump (a) A partial vacuum is created at A (b) Oil trapped between gear tooth’s and pump antiwar housing is 14. As per Bernoulli principal if air passes through a convergent tube (a) Pressure will increase and velocity decrease (b) Vel increase & pr. decrease (c) Vel. Increase & pr. Decrease with decrease temp 15. MTCS regarding thrust reversor (a) Mixed exhaust type engine need only one reversor (b) In high by pass turbofans reversor of secondary air is more effective than that of primary air (c) Both primary and secondary flow are reversed by using two reversor (d) All of the above are correct 16. Fig. Annular combustion chamber MTCS (a) This type of chamber given more mechanical strength (b) Makes well utilization of available space (c) Side efficient combustion act reduce power & high altitude (d) All are correct 98
17. Resin used for engine cowlings (a) Epoxy (b) Thermoplastic resin (c) Thermoset resin (d) Hybrid matrix 18. Inlet for coolings air for the first stage turbine blades is from (a) Gill holes (b) Blades root 19. Max forward thrust is produced by (a) Diffuser (b) Compressor (c) Combustor (d) Exhaust unit 20. Maxi energy jet blast is provided by (a) Turboprop (b) Turbo shaft (c) Turbo fan (d) Turbo jet 21. Magnesium is uses to east compressor case because of (a) Good case properties of Mg (b) No complicated prosses are involved 22. Mandatory fuel additive is (a) Funglcide (b) Anticorrosive anti-oxidising (c) Anti- icing (d) All above 23. The figure shown in typical igniter plug for turboprop engine. Mark the correct statement regarding it (a) The holes are provided for cooling (b) The body provides positive current path (c) All the above are correct 24. Oil system generally used on most modern turbine engine is (a) Wet sump type (b) Dry sump type (c) Low pressure system (d) High pressure system 99
25. Front bearings supporting the compressor drive shaft in a small business jet is (a) Roller (b) Hall (c) Taper roller (d) Depends on the radial longs impened on engine 26. In the given figure of oil filter (a) A & B are inlet parts (b) D is filter drain for maintenance purpose the filter becomes slogged (c) All the above the correct 27. In the figure of nozzle diaphragm assembly the splinge are provided are provided for (a) Locking spring (b) Labry in the seal 28. In the figure the rain locking part is (a) A (b) B (c) Both A & B (d) None 29. Rotation pad on Accessory drive gearbox is provided for (a) For N2 rotation (b) Alternate techno-generator (c) Balancing of fan can be done (d) All the above are correct 30. Methyle browide fig extinguisher has been accidentally discharged to return the engine into service: (a) Wash the engine into service (b) Wait for atleast 3 hrs so that the extinguishing agent evaporation (c) Operate the engine at idle low power (d) Carry out electrolytic compressor wash 31. At ram recovery point (a) Pressure increase neutralizes the friction losses in inlet 32. In the given 1 – 7 graph (a) One event is at constant volume (b) Shown line is the compression stroke (c) All the above are correct 33. In the given figure of ignition system, the 100
(a) C4 is a tank capacitor (b) L-c circuit is radio noise filter (c) S is a buler capacitor (d) All the above are correct 34. The point of height pressure in the gas turbine engine is (a) Compressor (b) Diffuser (c) Turbine (d) Exhaust nozzle 35. Mark the correct statement (a) In the stator the pressure of the air increase and velocity a decreases (b) The velocity loss is restored by the angular deflection of the air through rotor (c) Inlet guide vane inlet & exhaust velocities are equal (d) All the above are a correct 36. In the APU (a) Turbine blades are made of titanium (b) APU has reverse flow combustion chamber (c) It is supported on the plain journal bearings at the front and roller bearing (d) None of the above 37. Pour point is expressed in (a) Decimal (b) Centi stroke (c) Poise (d) Degree F 38. Win the given figure point (a) Provide for geroscopic inspection (b) Remains locked during the engine operation (c) To fixed starter (d) To provide for manual crank of gas turbine engine 39. The hardware used in gas turbine engine, which bolt is cd. Plated. (a) Both A and B (b) A (c) B only (d) All A B and C 40. Mark the correct statement 101
(a) Government spill valve acts as a safety relief valve (b) Engine speed governor acts as a relief system (c) Both a and b are correct (d) None of the above are correct • In is only for AIAMESWA members. • Members can obtain the question papers from their respect are regional local secretaries by paying normal photocopy charge. • Question papers can be obtained from the central office directly, New Delhi on payment of Rs. 10/- for each paper through DD in favour of the AIAMESWA, New Delhi. • To increase participants in preparation of the question papers, the association has decided to furnish the copy of the question papers fuel of cost to the members who send at least so objective and 4 subjective type question to us. 41. In the fuel control unit of hydro mechanical system if the engine all elevators without throttle movement, it is due to (a) Less of speed sense (b) CIT sooner failure (c) CIS dense (d) All are correct 42. The gearbox gasing is made of (a) Aluminum (b) Magnesium (c) Steel (d) Nickel 43. Compressor air leakage in a turbine of an engine is noted by (a) Rise in RPM (b) Rise in vibration (c) Rise in EGT (d) All the above 44. Pintle valve are used in (a) Vane type pump (b) Radial piston pump (c) Axial piston pump (d) Gurotor pump 45. With the change in the altitude or forward speed of the a/c the our capsule assembly in the fuel control unit in (a) Capsule assembly expanded 102
(b) Capsule assembly compressed (c) No changed in capsule assembly (d) None of the above 46. Match the following component with their method of processing Engine inlet camshaft nozzle turbine (a) Spin casting (b) Send casting (c) Spin casting (d) Send casting
Sinning Forging Forging Forging
ECM ECM ECM EBM
ECM EBM EBM EBM
47. During operation of the engine equipped with water injection system the watering of the coolent to the system is (a) Due to atmosphere pressure (b) Due to altitude change (c) Selected by the pilot (d) None of the above 48. Mark the correct statement (a) Humidity has formally large effect on the reciprocating engine (b) Humidity has loss effect on the gas reciprocating engine (c) Both jet and reciprocating engine are equally affected by the humidity effect. (d) None of the above are correct 49. Mark the correct statement (a) Starter drives the N2 compressor (b) Starter drives the N1 compressor (c) Quill shaft breaks if the sessing switch fails to disengage the starter (d) A & C are correct 50. In a gas turbine engine, velocity type and accelerometer type vibration indicators are used, in which: (a) Velocity type reads in VOLTs and accelerometer type in COULUMBS (b) Velocity type is less reliable than accelerometer type 51. The lowest TSFC is of (a) Turbofan engine (b) Turbojet engine (c) Turboprop engine (d) Turboshaft engine 103
52. The purpose of the inlet guide vanes is (a) To increase the pressure (b) To increase the velocity (c) To direct the air without changing the pressure & velocity 53. When anti-icing system is switched ON (a) TGT increased (b) EPR decreased (c) N2 decreases (d) All the above are correct 54. When fire extinguisher bottle is discharged due to high temp (a) Red disc is blown out (b) Yellow disc is blown out (c) It is indicated in pressure gauge (d) None of the above 55. Identify the following symbols: (a) Motor Relief valve (b) Pump Relief valve (c) Pump Heat exchanger (d) Motor Relief valve
cooler Heater heater heater
pressure gauge pressure gauge temperature gauge temperature gauge
56. The pitch movement of the propeller blade is controlled by a hydraulic servo piston the increase of oil pressure in the servo makes the propeller blade to (a) Low pitch rotation (b) High pitch rotation (c) Run at low RPM (d) High pitch with high RPM 57. The firing end of the low voltage igniter should be (a) Cleared using dry cloth (b) Cleaned using fibre bristle brush (c) Any one the above could be used (d) Never cleaned 58. Mark the correct statement with respect to engine bearings (a) Atleast one ball bearing must be in the front of the engine (b) Deep groove thrust bearing support axial and radial loads (c) Load carrings capacity of roller bearings is better than the ball bearing (d) All the above
104
59.The free turbine turboprop engine has different control levers is the cockpit the power lever directly controls the (a) Gas generator speed (Ng) (b) Power turbine speed (Nf) (c) Propeller governor (d) All the above 60. The compleate control of a modern APU is performed by microprocessor based electronic control box. (ECB) the input of the box is from (a) APU analog input (b) As in (a) and APU discrete input (c) Aircraft discrate input (d) Analog and discrete from APU along with the signal from aircraft. 61. In commercial turbofan power management control (PMC) provides an electronic override of the MEC to correct fan speed which is a function of (a) Power lever angle (b) Fan inlet pressure (c) Fan inlet temperature (d) All the above 62. Modern jet engine uses a accelerometer to pick up engine vibration the indicator must have (a) Charge amplifier (b) Voltage to current converter (c) Current limiter (d) Voltage limiter 63. A free turbine turbo shaft is running at higher RPM there is loss of oil pressure the probable cause is (a) The relief valve struck in closed position (b) The relief valve struck in open position (c) Filter clogged (d) Oil spray jet clogged 64. When Pt2 is blocked due to ice formation then the EPR gauge will (a) Over read (b) Under read (c) Read zero 65. Which one of the following scale is high pressure system (a) Lip (b) Cup 105
(c) Carbon rubbing (d) All the above 66. When oil filter particle dissolves fully in Aquous solution of ammonium nitrate, the particle is (a) Tin (b) Cadmium (c) Aluminium (d) Silver 67. The figure given below is or APU fitted in modern boeling aircraft the air inlet in the figure in (a) C (b) A and B (c) D (d) None of the above 68. During preflight inspection the crewmember find that the amber deck of the fire warning light appears out this indicates (a) The extinguishing agent in bottle is over pressurized (b) The extinguishing agent in discharged due to over temp. (c) The extinguishing agent in the bottle is at low pressure (d) The extinguishing agent in discharged due to cook pit control 69. When the air starter over speeds due to failure of internal switch mechanism (a) The engine RPM continues to rise until it reaches idle RPM (b) The volume to starting air automatically decrease to overcome the situation (c) The drive shaft breaks (d) Any the stated above may happen 70. Engine operating instructions are OK except flam out during deceleration the most likely cause is (a) Acceleration deceleration valve (b) Maximum flow valve setting (c) Minimum flow valve setting (d) Governor setting. 71. At cruise condition the pilot observes fluctuation of EGT about 30 but the EPR and RPM are study. The part of engine defective is (a) Combustion chamber (b) Pyrometer system (c) Turbine (d) None of the above 106
72. The graph indicates the specified fuel consumption at standard level pressure is of (a) Turbo prop (b) Turbo jet (c) Turbo fan (d) All of the above will have same graph 73. The figure is of air intake having electrical anti icing (a) Outer surface is continually heated (b) Forward surface is cyclically heated (c) Welding will reduce the resistance of the elements (d) There is no overheat protection on ground 74. The centrifugal compressor is shown (a) A (b) B (c) C (d) None of the above 75. In the figure (a) Fl is the fuel manifold supplied fuel at starting (b) F2 is the fuel supplied for all the points (c) The airflow blow away and carbon deposits (d) All the above are correct 76. Mark the correct statements (a) Whittle burner min. pressure loss (b) Annular (c) Can – annular best efficiency (d) Cannular – best utilization of available space 77. Match the following (a) Solenoid (b) Relief valve (c) Back pr. Valve (d) Annular
-
LP speed governor Fuel pump Spray nozzle Dash feed throttle.
78. Identify the turbine blades: Fir tree root Fir tree root BMW hollow blade De-level bulb ------------------------------------------------------------------(with lock plate) (with shank seal) (with retaining pin) (with look sc) 107
(a) A (b) B (c) C (d) D
B A D C
C D A B
D C B A
79. In the figure (a) R is the bleed resistor (b) R grounds the earth charge of the trigger capacitor turning each cycle. (c) When the ignitor is not triggered, R grounds the current (d) All the above are correct 80. Mark the correct statement with respect of single speed engine shown being more comp. Stage than turbine because. (a) Compressor material is what before cannot take the load (b) It’s different to get compression due to diffusion in less stage (c) All the above are correct
JET ENGINE(JUNE 95) 108
1. Consider forget turbine helicopter engine running at max. gas generator speed any increase of load will (a) Reduce NTL only (b) Both Ng and NTL will increase (c) Bring down gas generator speed (d) Increase Ng and decrease ferr turbine speed (NTL) 2. Refer the fig. Of turbine disc/blade and mark correct statement (a) Teritiary creep is independent of gas temperature (b) The rate of primary creep is always less than of the secondary creep (c) The middle portion of the blade is exposed to high temp than root and tip of the blade (d) All the above are correct 3. When a turbojet engine operating at steady state max RPM any increase of airmass flow due to inlet variable (a) May increased the compression ratio (b) May decrease the compression ratio. (c) Not affect the compression ratio (d) None of the above 4. The following fig shows a electrical tube anti icing system of an enging inlet. (a) Outer surface is continuously heated (b) Repairing element by welding decreases the element resistance (c) Forward element is cyclically heated (d) There is no over heat protection when the A/C is on the ground 5. The principle involved in controlling the fuel flow according to the requirement of he engine? (a) Keeping the delta pressure across the metering valve constant and changing the cross section of the orific (b) Keeping the constant section of the orific constant and varying the dolta pressure across the metering valve (c) Sessing the feed back from RPM and EGT thermocouple and controlling the fuel through the electronic controller. 6. Hottest section of the engine is (a) Combuction chamber casing (b) H.P. turbine casing (c) L.P turbine causing 109
(d) Jet pipe casing 7. When CDP sensor fail during cruise condition or high power condition the engine will. (a) Flame out (b) Surge (c) Decelerate to idle condition (d) Accelerate to max power condition 8. On a twin spool turbofan engine with electronic TGT limitor (Amplifier) all engine paramotors are fluctuating at max. RPM this is due to malfunction of (a) Amplifier (b) TGT thermocouples storm (c) N1 senser system (d) Any one of the above 9. Mark the correct statement regarding cracks (a) A & B can be detected by longitudinal magnetization (b) B can be detected by either circular or longitudinal magnetization (c) C can be detected by circular magnesation. (d) None of the above 10. The advantages of the type of injector shown in the figure is (a) Fuel regulator not required (b) Two injectors are used in an engine. (c) Does not depend on rate of fuel flow (d) All the above are correct 11. In a typical turboshaft free power turbine engine, the FCU basically senses. (a) The power lever governor free turbine (b) The power turbine (c) The power lever governor free turbine through power turbine (d) Gas generator ESSAY - TYPE 1. A modern aircraft fitted with two turbofan engines is O.K during engine ground run performance. The aircraft was released for flight with instructions to the pilot. During take-off run, there was a jerk with rise in EGT, severe EPR fluctuation and vibration. The pilot aborted the take-off. (a) What is the cause and the events took place in a sequance? 110
(b) What are the critical areas to be checked for the cause and the remedial action. 2. (a) What will happen if the P & D valve is struck in open condition during starting? (b) What are the functions of straightening vanes of exhaust cone? (c) How the micro organism form in the fuel how they affect the fuel system and its components? How they are detected? (d) What are the areas to be checked for high oil consumption? (e) What is the trim balancing? 3. How will you check the serviceability of the following I. LOP switch II. Tacho generator III. Surge bleed valve IV Oil temp. bulb V Thermocouple harness VI RPM pulse pick – up b. Describe the serviceability check of H.E ignition system. 4. In the figure given below (a) Identify the parts (b) Explain the purpose of various parts. a. How will you perform emergency shut down of APU during ground run b. Where are the boroscopic inspection holes are provided in the engine and how and they helpful in monitoring the health of engine? c. What actions you will take during fire warning stall/surge and engine flame out? 5. Titanium should not be cleaned (a) Trichlor ethylene (b) Rx 222 6. RD 2490 is (a) Corrosion inhibitor (b) Synthetic oil (c) Cleaning agent (d) None of the above 7. After shut down of engine the boost pump should never be put off until the engine rotor stop this make that the (a) EDP do not loose prime (b) F & D operate correctly (c) Fuel pump life more (d) Fuel filter operation is satisfactory 111
8. In hydro mechanical fuel control if CIT sense fail on hot day then engine (a) Takes more time to accelerate (b) Run at low RPM (c) Surge and EGT may occur (d) All the above are correct 9. Crack pressure adjustment of P & D valve is at low side (a) Secondary fuel flow casier (b) High EGT starter acceleration (c) Reduce stall margin (d) All the above 10. The vibration indicator pick up is mounted in the turbine casing it indication (a) Turbine vibration only (b) Turbine and turbine casing vibration (c) Turbine and compressor vibration (d) All above 11. The blades of the compressor are twisted. This make blade (a) More pressure on the blade tip than the root (b) More pressure on the blade root than the tip (c) More pressure at the middle portion of the blade (d) None of the above 12. For the water particle inspection of the fuel the water indicator paste is applied at the bottom of the sample bottle if the water is present in the fuel (a) The past will come to from the bottom (b) The bottom of the bottle will be discoloured (c) The complete sample will be discoloured (d) None of the above 13. A turbofan engine produce. A thrust of 9100 lbs, the fuel consumption is 700 Gallon/hr. The SPC will be (a) 0.07 lb/lb/hr (b) 0.5 lb/lb/hr (c) 0.6 lb/lb/hr. (d) 0.7 lb/lb/hr. 14. The diagram is of a single hydraulic actuator for satic vanes the is will be (a) 200 PSI 112
(b) 20 PSI (c) 10 PSI (d) 200 PSI 15. Compressor blades are not fitted rigidly on the nut there is a slight movement this is done to (a) Provide case of replacement of blade (b) To provide relief for the expansion of the blade due to heat (c) To reduce vibrational stress on the blade (d) All the above 14. The baffles plates are incorporated in the oil tank the of this plate is (a) To avoid local turbulence and recirculation of used of (b) To settle down the foreign particles in the bottom (c) They give cooling capacity (d) All the above are correct 15. For soap analysis the sample must be collected (a) Within ½ an hour of the engine shutdown (b) After enough cooling of the engine (c) After half an hour of the engine showdown (d) Any time 16. For a given EPR if the OAT decreases the N2 RPM of turbofan engine will (a) Increase (b) Decreases (c) Remain same (d) Increases N2 with decrease of EGT 17. If engine fitted with hydro mechanical FCU when speed sense N2 fails during IDLE condition the engine. (a) Flame out (b) Can not accelerate above IDLE RPM (c) Accelerate to high power bottj (d) None of the above 18. Match the following (a) Threaded (b) Un threaded (c) Greased blank (d) Grease proof paper 19. Match the following (a) Injector wheel
(a) Air intake (b) Fuel lines (c) Compressor of take (d) Rubber part (a) Simplex 113
(b) Secondary burner (c) Double cone (d) A square low injector
(b) Centrifugal (c) Duplex (d) Pre vaporization form.
20. Match the following Differential pr. Aerodynamic Pressure acro On vane produces force produces Vane (a) Torque load pending moveincreases ment (b) Bending moveTorque load. increases ment (c) Bending moveMent Torque load constant (d) Torque load. Bending load. Reduced 21. Match the following starting control (a) Droop cam (b) 3D cam cam (c) 3D cam cam (d) droop cam 22. Match the following (a) Blade rotainor (b) Spacer (c) Spinner road cone (d) mid span shroud
Angle of incidence &Subsequent stage Reduces Increases
increases Increases
study state control acceleration 3D cam Droop cam 3D cam 3D cam
decreases 3D cam Droop
3D cam
Droop cam
Droop
Droop cam
3D cam
3D cam
(a) In assembly stiffness (b) Radial movement (c) Axial movement (d) Axial stability on rotation
23. Match the following structural most efficiency no stability (a) Can annular annular Double annul (b) 114
easy inspection
For lower emission
Can annular
24. If the spring prossure of the P & D valve is weak each (a) The engine will run at lower RPM (b) The engine will run at higher RPM (c) Higher EGT (d) All the above 25. The transformation of kinetic energy in to pressure energy is NIL in which type of engine (a) Turbo prop (b) Turbo jet (c) Turbo shaft (d) By passed fan 26. Bell mouth compressor is used in engine calibration on ground because (a) The duct loss is so small that it is considered zero and the engine performance date can be gathered without any correction for inlet duct loss being necessary 27. The purpose of slot in the fig. Of impeller (a) Used for balancing (b) Ease of fitting in the zig and fixture during manufacturing (c) Surge protection (d) All the above are correct 28. In fig. The area of the compressor casing the gradually decreasing if it is constant (a) Velocity decreased (b) Velocity in even 29. Match the following (a) EGT (b) Acceleration (c) Oil pr. Transducer (d) Fuel flow transducer
(a) D.C. pulse (b) EMF (c) Charge (d) Reluctance
30. In the Fig of ignition system R is (a) A co (b) Filter (c) Vibrator (d) To producer India interference 31. In case of post exit thrust reverser (a) Down lock pressure is less than the reflecting pressure (b) Down lock pressure is more than the deflecting pressure 115
32. In the APU of the A/C holes are provided near the exhaust the pu is to (a) Exhaust duct air intake cooling oil breather (b) For cooling (c) Exhaust of QPU 33. In the secematic of the fuel filter (a) A is the inlet (b) B is the inlet (c) C is the inlet (d) Either A or B is inlet 34. The figure indicates (a) Compressor (b) Turbine (c) Fan (d) Can not be indentified 35. In the efficiency graph shown A, B, C, D stand for A B C (a) Turbo prop Lowby pass high by pass (b) Low by pass turbo prop turbo jet pass
D turbo jet high by
36. In the filter system if both the filters are clogged the pressure at A will be (a) 10 PSI (b) 60 PSI (c) 30 PSI (d) 20 PSI
JET ENGINE 93 1. Alloy used for stringer is (a) 7075-T 76 116
(b) 7075-T 6 (c) 7075-T 36 (d) 7075-T 36&7075-T 73. 2. A+ Aerodynamics center the potching moment Co-efficient is (a) dependent upon co-efficient of lift (CL) (b) dependent upon co-efficient of lift & CP (c) constant and independent of CL (d) Dependent upon CL& center. 2. Mark the incorrect statement.
(a) For minimum drag the lift co-efficient is equal to its lift dependent drag Co-efficient. (b) At higher incendents lift arises from difference between reductions on upper & lower surface of wing. (c) For thin aerofoil of infinite aspect ratio in super sonic flow the aeroplynic center is at 50% of chord. (d) Activity factor is measured on power absorption of Air serves. 3. Location of c.p is a function of –Ref page automotive flight construction. (a) Camber (b) CL (c) Camber & CL varies with angle of attack (d) Camber varies with angle of attack 4. The angle of attack at which fail moment is equal to using movement (a) Neutral point (b) Trim point (c) Stick fixed point (d) Stick free point @ s/p. 5. Degree of longitudinal stability is effected by relative position of both (a) Center of pr & aerodynamic center (b) CP & CG (c) Aerodynamic center & C.G (d) Aerodynamic center & angle of attack 95/F. 6. Static Margin is the distance of (a) Aerodynamics center to neutral point (b) C.P is neutral point (c) CP&C.G (c) CG to neutral point 7. Tab used at high speed 117
95/F
(a) Servo tab (b) Balance tab (c) Spring tab (d) Trim tab 95/F STRUCTURE 9. The station number is distance in enhance from (a) A yew reference point forward of fuselage (b) Reference point on the nose tip (c) Reference point at wing of empty a/c. (d) Reference point at the most forwarded C.G point of empty a/c 10. The languorous are (a) Rolled HAT section (b) Extracted z sections (c) Rolled & extracted z sections (d) Rolled & forged z sections. 11.Extensive use of metal biding in a/c constructions (a) Fatigue resistance only (b) Corrosion resistance of only power (c) Fatigue & corrosion resistance (d) corrosion resistance wire 12. Inboard & king of taper rolled provide (a) Max thickness area of heavy loading (b) Min thickness area of reduced loading (c) Thickness skin at root and across fuselage. (d) Thickness at high tort ional loads 13. Plate between front and rear span (a) Has thickness tapered (b) Is butt spliced (c) Has tapered thickness and is but spliced (d) Has tapered thickness with flush fastness 14. Alloys use in a/c are hardened by (a) Cold working (b) Aging (c) Heat treatment (d) Chemical treatment. INSTRUMENTS 15.In sensitive ASI the scale can be made liner by (a) Introducing banana shaped slat in the toothed wheel, which meshes with pointer percon (b) using turning spring (c) Keeping capsule in mathematically curved shape 118
(e) All the above. 16.Max safe airspeed criclicator (a) Does not require true temperature compensation (b) Require true max safe and total Airspeed (c) Has a subsidiary scales which can be set to max speed of given a/c and structure (d) None above is correct 17. Mark the correct statement (a) There is no apparent wander of gyro at equator (b) If gyro is moved from north pole to south pole around earth surface than the apparent wonder would change from counter clock wise to clock wise (c) Error due to apparent wonder at any point is to 15Lat/hr (latitude in degree) (d) All the above are correct. 18. In ratio meter type instrument (a) Coil carring stranger current moves in stronger part of it (b) No effect of flucations of input voltage (c) Controlling force provided by spring is quit stronger and has to counter balance 19. Artificial Horizon (a) Has a complete freedom 360° in roll and 85° freedom input is hat it is difficult But not impossible topple the horizon (b) Has a wonder rate of gyro less than 15° per hour (c) Has a gyro axis titled forward about 15° to compensate to rate of turning (d) All the above are correct. 20. If a/c alternates on easterly heading the compass will indicate (a) Apparent turn towards north (b) Apparent turn towards south (c) Doping of compass (d) None of the above. 21. Hear spring is a instrument (a) Is provided to negative back lash and statement (b) Serves as controlling force against reflecting force (c) Is strip of Nl, Fe alloy to sensitive to allows greater amount of flux between the pole to pole temperature when temp increases + statement (d) None of the above 119
22. Air speed indicator measures (a) Dynamic pr (b) Dynamic-static pr(c) Dynamic+static pr (d) Staticpressure 23. Cabin altitude indicator is (a) An alternator calibrated to some pr latitude test as a normal altimeter (b) A bounden type pr gauge (c) Contains siphon open carbon (d) None of the above 24. Rate of climb indicator is (a) A different pr gauge to indicate rate of altitude change (b) Not a ∆ pr gauge sime operation depends upon static programme (c) Having, is most cases, a logarithmic scale as it is advantageous in start & statement (d) Effected by position error 25. Rate of climb indicator (a) Has two springs for selling range, which bears on stem connected to center piece. (b) With range setting spring to extent force of capsule to achieve relation between capsule pr deflection characteristic (c) Has spring screws the upper row of screws to upper row of spring control rate of decent calibration (d) All above the are correct 26. Dip magnetic compass (a) Is caused by the horizontal component of earths magnetic field (b) Is called by vertical component of earth magnetic field (c) Is max at equator & min at poles (d) Both a & b are correct 27.If pilot tube is blocked airspeed indicator reading while sending will (a) Decrease (b) Increase (c) under speed (d) over head 28.ASI indicator can be modified to read (a) Equivalent air speed (b) Mach numbers (c) True air speed (e) All the above AERO POLIT
120
29. In two phase induction motor type of serve motor of an auto pilot the reference phase is supplied by (a) 26v 50 Hz (b) 115v, 400Hz (c) 240v, 400Hz (d) 220v, 50 30.When automatic control is selected in electro HYDRAULIC auto pilot system (a) The engage com is out of detent (b) Engage signal is fed to the 5.0 volts (c) a & b (d) Pilot control valve is operated 31. The component different between position control servomechanism and speed control mechanism is (a) Serve motor (b) Techno generator (c) Potentiono meter (d) error detector 32.Mark the correct statement (a) Yaw damper will not oppose pedal movement of pilot (b) The speed monitor identifies speed a/c for application of control (c) In disengage condition of electro prumatic Autopilot the lines and pistons are retracted. (d) Under normal condition of load, the torque applied to input member by servo meter is transmitted to intermediate member. 33. When control wheel is released in control wheel sterling the automatic control (a) Holds a/c at originally selected altitude (b) Is provided by a pilot & Roll forces simultaneously pilot through force transactions (c) Holds the a/c a newly established altitude (d) Both b& c correct. 34.Wing leading edge using control achieved by (a) PrerumaticThermal & thermal system (b) Thermal & electrical system (c) Electrical & Alcohol system (d) All the above 35. Thix tropic Agent (a) Decreases stress (b) Decreases temp sensitivity (c) Increases stress (d) Increases temp sensitivity 121
36. Expansion slot in rotary brake discus assembly (a) Prevents excessive heat description (b) Prevents warping from heat (c) Enhance heat disruption (d) Increases efficiency of brakes system when brakes area 37. Mark the correct statement (a) Pr demand type of regulator is used for both crews (b) Pr demand type of regulator is used only for crew 38. Upper & lower bearing in main L/G shock strat programme (a) Only sliding surface between inner Souter cylinder (b) Only air seal between inner & outer cylinder (c) Only sliding surface with minimum friction (d) Sliding surface and air seal between inner souter cylinder 39. In HYD main L/G system the rate of gear extension is slowed by (a) In build snubber design (b) Check valve is upline (c) Orifice check valve in down line (d) Orifice check valve in upline 40. What prevents L/G from being retracted after has lowered (a) Lock strut (b) Down lock & Lock strut (c) Down lock (d) Down lock & weight of the a/c
41. Some relief valves provide an overflow features to (a) To provide pr lock (b) Prevents cavitations (c) Test reverse flow chalk valve (e) Compensate for temperature variation
42. Mark incorrect statement (a) HYD fuse is device to seal broken HYD line (b) Follow up selector valves are used in L/G system (c) Pr relief valves are priority valve 122
(d) Sequence valves are sprout type and by pass check valves 43. In angular type HYD pump the angle between cylinder block axis and drive shaft axis can be varied by (a) Pr control unit (b) Spring unit (c) Contrail cylinder (d) Swivel yoker 44.When sprout type hydraulic pr regulator is in KIKKED” in piston the directional sprout is in a position to direct pr to (a) The pilot valve to keep it open (b) The unloading valve to keep it closed. (c) The unloading valve to it open (d) The pilot valve to keep it closed. 45.Fittings used to attach the MLG to wings are secured with (a) Interference fit (b) Closed tolerame fit (c) Both a & b (d) Permanent type 46. Antiskid system (a) Can use mechanical fly wheel type of skid detector (b) Can use electrical & selectronic type skid detector (c) Provides optimum braking and avoids dragging of wheel (d) All the above are correct 47. Co lour Hyd system tabbing is (a) Yellow, blue, Yellow (b) White, blue, white. (c) Blue, green, blue 123
(d) Light blue, Yellow, Colorless.
PRESSURISATION 48. A line from isobaric control valve to the throat of ambient venture (a) A low pr reference to manual controller (b) A low pr reference to auto controller (c) A high pr reference to manual controller (d) A high pr reference to auto controller
49. The rate of selection of pressurization system regulates rate of air flow between (a) Control chamber & venture (b) Rate chamber & venture (c) Controller chamber & rate chamber (d) Rate chamber & manual controller 50. Mark the correct statement (a) Vacuum relief system provides automatic control signals only (b) Vacuum relief system provides both auto & manual continue signals only (c) Positive pr. Relief valve is built in to the flow valve (d) Cabin barometric selector control landing field altitude
51. The purpose of negative pr relief valve is to (a) Select pressurization at stations when aerodrome elevation below sea level (b) Allow out –side air to enter fuselage when out side pr is greater than inside pressure 124
(c) Allow out flow to open when inside pr greater than ambient (d) Half differential pr. Relief valve in case ambient pr become less than pr inside airplane 52.Turbine engine air is used for air conditioning & pressurization cooled (a) Compressed air (b) Ram air (c) Conditioned air (d) Bleed-Air. 53. How the cabin of an a/c usually controlled (a) By pressure automatic out flow that dumps all pressure excess of the amount for which it is (b) By pr- sensitive valve that consents output of pressurization pump.
54. Cooling device in planes consist of (a) Fam air, Ram air actuator, ACM (b) Primary H.E., secondary H.E., and Fam air (c) ACM, primary H.E., Fam air (d) ACM, primary H.E., 7 secondary H.E., 55. Air in pack is at lowest temperature at (a) Out let of primary H.E., (b) Out let of secondary H.E., (c) Inlet of compressor (d) Out let of turbine
56. Out flow valve is for (a) A./c system only (b) Pressurization systems only (c) A/c & pressurization systems only (d) A/c & recirculation only 57. In the event of pressurization failure protection by 125
(a) Positive pr. Relief valve (b) Negative pr. Relief valve (c) Servo valve (d) Check valve 58.In pressurization system mode selection switch on ground (a) For recirculation (b) For ground operation (c) For controlling cabin temp on ground (d) For ground operation of ventilation systems 59. A small orifice in manual control pressurization valve provides (a) High pr reference for manual controller (b) High pr reference for auto controller (c) A low pr reference for manual controller (d) A low pr reference for auto controller
1. Centre of pressure is the point From which total lift four outs. 2. The Static margin is The CG location which produce neutral statics 3. If an a/c has directional static custability, displosure in YAW will cause – Directional devergenic 4. The purpose of primary stups in flight controls system is to – Restrict the moment of the control to their current range 5. If a gyroscope positional at a latitude has an opp drift of 15° sin its input axis would be alighned – local component of earth rate. 6. The effect of an ocillation or wobbling of a gyrosonic spin axis is known as – nutation 7. In connection with command signal processing, the function of adapting control system response to an a/c handling qualities known as – gain programming. 8. In order to derive D.C. control signal having phase relationship as an A.C. signal, it is accurate for signals to be - demodulated 9. In terms of pressure ratio, mach no is equivalent – P-s/s 10. Heading hold signal from auto flight control system are supplied to the – roll channel 126
11. AZIMUTH information during an ILS approach is provided by signals from – localiser transmitter. 12. A parallel – connected servo motor is one which moves both appropriate flight control surfaces and pilots control. 13. The to – from indicator of an HIS is in operates which only the VOR mode is selected. 14. When failure data signals occurs, indication is given on EFIS display units by flags displayed in - yellow. 15. Logic gates – ref page 275 auto flight
127
