Module 5

Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions

Module 5 Digital Techniques/Electronic Instrument Systems 1. An FMS system, besides controlling navigation, thrust and auto-nav, also provides a) take-off and landing warnings b) dedicated status and warnings c) GPWS warnings 2.

EADI sky and ground display is provided by a) synthetic TV signals b) raster scan c) stroke pulse

3.

HSI heading is valid if the heading flag is a) in view b) green c) out of view

4.

A NOR gate with both inputs inverted becomes a a) NAND gate b) AND gate c) OR gate

5.

An ARINC 429 binary coded decimal data word occupies bits a) 11 to 28 b) 11 to 29 c) 1 to 8

6.

A fibre optic cable consists of a) a plastic core with a cladding having a higher refractive index b) a silica glass core with a cladding having a higher refractive index c) a silica glass core with a cladding having a lower refractive index

7.

The command bars on an ADI relate to a) path required b) path being followed c) roll indications

8.

The recording medium in an FDR is a) a high density floppy disc b) magnetic tape coated with ferrite c) copper foil coated with ferrite

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 9.

Convert 0111012 to octal a) 25 b) 33 c) 35

10.

What does the CADC feed a) Altimeter / FMS / secondary radar b) standby altimeter / machmeter c) cabin pressure controller sensor / machmeter / altimeter

11.

ARINC 629 databus is a) one cable, bi-directional b) two cables, bi directional c) two cables, uni-directional

12.

Requirements for software control can be found in a) AWN 45 b) JAR OPS c) JAR AWO

13.

Software can be modified by a) licensed avionics engineers b) the manufacturer c) The same rules apply as to modifications to hardware

14. Two connected fibre optic cable ends are parallel but not quite touching. This is called a) lens connector b) end to end coupling c) end fire coupling 15.

A disadvantage of a fibre optic cable is a) shallow bend radius allowed b) couplings susceptible to ingress of fluid c) end terminals are susceptible to environmental contamination

16.

The inside of a CRT consists of a) an oxide coating and rare mercury gas b) a phosphor coating and rare mercury gas c) iodine and rare mercury gas

17.

What kind of light is used in fibre optic systems? a) Infrared b) Visible c) Ultraviolet

18.

Typical displays on an EHSI are a) VOR, Map, Plan and weather radar b) VOR, Plan, Map and Attitude c) Engine indications

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 19. An EADI display showing a moving runway moves down during the final stages of an approach. The aircraft must a) fly up b) fly down c) hold descent path 20.

An ARINC 573 data bus is used a) to input into a Digital Flight Data Recorder b) to input into a FDR Digital Acquisition Unit c) to supply digital inputs from a Symbol Generator to the EADI and EHSI

21.

A flight data recorder can obtain information from aircraft instruments a) provided there is adequate isolation b) by direct connection to the instruments c) provided there is adequate damping

22.

Adding invertors to the two inputs of an AND gate makes a a) NAND gate b) OR gate c) NOR gate

23.

An ARINC 429 bus uses a) a twisted shielded pair of wires b) two bi-directional twin sheathed and earthed wires c) a single twin wire cable for each transmitter

24.

CRT horizontal beam control is achieved by a a) square wave b) sawtooth wave c) sinusoidal wave

25.

The ARINC 429 data bus word systems use a) decimal numbering b) hexadecimal numbering c) binary coded decimal

26. a) b) c) 27.

The binary number 11010111 expressed as a decimal is 207 223 215

The octal number 1001 expressed as a decimal is a) 65 b) 513 c) 9

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 28. C B 0 0 0 0 0 1 1 1 a) b) c) 29. # 30. #

This truth table is for a A 0 1 0 1 NAND gate AND gate OR gate

The inputs and outputs of a CADC are a) pitot and static in; altitude, attitude, IAS and VS out b) pitot and static in; altitude, IAS, mach and VS out c) pitot in; static, altitude, mach, IAS and VS out EICAS provides the following a) engine parameters only b) engine parameters and system warnings only c) engine parameters and engine warnings only

31. During an instrument approach, the glideslope pointer deflects below the glideslope centre mark. This means the aircraft is positioned # a) above the glideslope b) below the glideslope c) to the left of the localiser 32. Engine parameters are displayed on # a) ECAM b) EHSI c) FMSCDU 33. A central maintenance computer provides # a) ground and flight monitoring and testing on an on-board computer b) ground and BITE testing using a portable control panel c) display of system warnings and cautions 34. # 35. # 36. #

ARINC 573 is related to what system a) INS b) FDR c) Weather Radar The rising runway is positioned from information derived from a) barometric height b) vertical speed c) radio altimeter Where are the Digital Flight Data Recorder outputs supplied to? a) The recording unit b) Flight instruments c) There are no outputs Page 4

Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 37. FMS failure and warnings are # a) displayed on EICAS b) engine warnings only c) EFIS warnings only 38. Who is responsible for the operational program of the FMS? # a) The pilot b) The engineer c) The manufacturer 39. Flight director command bars are moved to the correct position by # a) position feedback b) amplifier gain c) calibration 40. If a signal has quantity in volts and physical position it is a) digital b) synchronous # c) analogue 41. In a CRT, if the magnetic field is parallel to the Y plates, what will be the direction of the electron beam movement? # a) Vertical b) No movement c) Horizontal 42. What is the fixed feature of an ADI? a) The glideslope pointer b) The lateral deviation bar # c) The aircraft symbol 43. Primary colours of a CRT are # a) red, green and blue b) red, green and yellow c) red, blue and yellow 44. What information is required before completion of the alignment of an Inertial Navigation System? # a) Aircraft present position b) Aircraft present position and heading c) Heading and attitude 45. IRS accelerometers are mounted a) 60o to each other b) 45o to each other # c) 90o to each other 46. An FMS navigation database is updated a) at the operators request b) once a month

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions #

c) every 28 days

47. A single failure of a fly-by-wire system # a) has no effect on aircraft operation b) will limit the flight profile c) will reduce operational heights and speeds 48. Fly-by-wire load alleviation function in turbulent conditions will result in a) ailerons moving symmetrically upwards # b) ailerons and spoilers moving symmetrically upwards c) spoilers moving symmetrically upwards 49. Fly-by-wire roll control is achieved by a) ailerons b) spoilers # c) spoilers and ailerons 50. The movement of fly-by-wire control surfaces are a) hydraulically controlled and electrically actuated b) both electrically controlled and electrically actuated # c) electrically controlled and hydraulically actuated 51. ARINC 629 current mode couplers are a) capacitive b) resistive # c) inductive 52. on an EADI, the Flight Director command bars show a) the actual path with respect to the required path # b) the required path with respect to the actual path c) the path with respect to the horizon 53. What instrument includes a display of a rising runway? # a) EADI b) EHSI c) ECAM 54. What are the effects of the X and Y plates on a CRT? a) X plates move the beam vertically, Y plates move the beam horizontal # b) Y plates move the beam vertically, X plates move the beam horizontal c) X and Y plates can move the beam in either direction 55. ARINC 629 data bus is a) two buses, unidirectional b) two buses, bi-directional data flow # c) one bus, bi-directional data flow 56. an FMS system, besides controlling navigation, thrust and auto-nav, also provides a) take-off and landing warnings

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b) dedicated status warnings c) GPWS warnings

57. In order to maintain HIRF protection, bonding checks between airframe and electrical components carrying voltages greater than 50 volts RMS or DC or main earth return should not exceed a) 1 megohm # b) 1 ohm c) 0.05 ohm 58. Ribbon cables effected by mutual impedance and current loop leakage should be protected by a) shielding each individual conductor b) connecting all conductors to a common earth # c) earthing each alternative conductor to separate point 59. EADI sky and ground display is provided by a) synthetic TV signals # b) raster scan c) stroke pulse 60. Normal transmission order of ARINC 629 LRUs in periodic mode is in order of # a) power up b) shortest to largest TG c) shortest to largest TI 61. What frequency creates the raster effect on a CRT? # a) 50/60 Hz b) 400 Hz c) 250Hz 62. If an EFIS has 3 symbol generators, what is the purpose of the 3rd symbol generator? a) Comparison with No.1 symbol generator # b) Standby c) Parity function 63. The sweep waveform used on a electromagnetic CRT is # a) trapezoidal b) sinusoidal c) sawtooth 64. FMS operational program is updated every a) 7 days # b) 28 days c) 90 days 65. Fibre optic data is sent by # a) modulating the frequency of a laser beam

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions b) modulating the frequency of a filament beam c) a strobe light 66. What is 345 in binary? a) 100111001 b) 110011001 # c) 101011001 67. Which logic gate can be represented as a parallel circuit? # a) OR gate b) Exclusive OR gate c) NAND gate 68. Software documentation procedures are laid down in # a) AWN 45 b) JAA Ops c) MOE 69. HIRF is prevented from entering a fibre optic cable by a) enclosing it in a metal braid b) grounding the fibre at both ends # c) using an opto-isolator coupling 70. In an ARINC 429 wordstring, bits 1 to 8 represent the a) source of message # b) monitored parameter c) destination LRU address 71. ARINC 629 terminal transmit interval is a) unique to each terminal # b) common to each terminal c) when all terminals are quiet 72. Continuity of a fibre optic cable is checked by a) a light source and an opto-power meter b) a calibrated light source # c) a calibrated light source and an optometer 73. To shield a fibre optic from EMI you must a) earth both transducer and couplings b) shield it with a braided shield # c) use an opto-isolator 74. A simbol generator displays ESDs warning. During replacement a) you must wear a wrist strap connected to an approved earth point # b) make sure the pins are not touched and covers fitted c) you must earth the unit to the airframe structure 75. Magnetic deflection on a CRT is achieved by a a) sawtooth waveform

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b) trapezoidal waveform c) sinusoidal waveform

76. An FDR fitted to a helicopter begins recording a) on take-off # b) on engine start-up c) when power is applied to the aircraft 77. MIL-ST-1533 is a data bus for a) Flight Data Recorders b) Inertial Reference System # c) Digital Information Transfer System 78. Making an invertor from a NAND or NOR gate is achieved by a) inverting the input b) connecting two in series # c) connecting the inputs 79. Parallel to series conversion is achieved by a) a parallel to series converter # b) a shift register c) a multiplexer / demultiplexer 80. The FMS databases consist of a) one navigation and one performance database b) two performance and one navigation database # c) one performance and two navigation databases 81. The FMS can update the IRS position outputs by using information from either a) VOR and DME only b) DME and GPS only # c) GPS, DME, LOC and VOR 82. The accepted error from INS/IRS is a) 1 mile/hour + 3 miles b) 2 miles/hour + 3 miles # c) 3 miles/hour + 3 miles 83. Before an IRS can complete the alignment sequence a) the shutdown present position must be entered # b) the current present position must be entered c) either the last or current position must be entered 84. within a computer controlled flight system, position feedback is converted from # a) analogue to digital b) digital to analogue c) position feedback to rate feedback

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 85. What shape does the waveform take to counter the impedence effect of the coils in an electromagnetic controlled CRT? # a) Trapezoid b) Sawtooth c) Rectangular 86. What warnings can an FMS provide? # a) Discrete warnings b) Spurious faults c) Ground faults only. 87. Centralised Aircraft Monitoring System a) performs in-flight and ground tests of aircraft systems by carrying out a BITE interrogation # b) give red warnings and amber cautions to display system status c) performs in-flight BITE interrogation only 88. The control of the speed or rate that the flight director command bars move can be controlled by a) position feedback # b) rate or velocity feedback c) amplifier gain 89. The Centralised Aircraft Monitoring System uses the maintenance mode of operation a) in the air only # b) on the ground only c) either in the air or on the ground 90. The third EFIS Symbol Generator is operated a) with EICAS b) in an emergency # c) as a standby to the No1 and No2 system 91. What functions are available on the EHSI? a) Full arc and Wx only # b) Full arc, Wx and Map Mode c) Full Arc only 92. EFIS displays of the right hand and left hand displays are compared by comparators in the a) FMS b) EICAS # c) Symbol Generators 93. What is the approximate earth rate? a) 5o/hour b) 10o/hour # c) 15o/hour

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 94. An IRS platform has a) two accelerometers # b) three accelerometers c) two or three accelerometers depending on the system 95. IRS Laser Ring Gyros provide # a) rate movement about an axis b) displacement about an axis c) both rate and displacement about an axis 96. What are the outputs of a Digital ADC? # a) TAS, MACH, Altitude, TAT and SAT b) TAS, MACH and Altitude c) TAS, MACH, Altitude and TAT 97. ARINC 629 periodic mode is used for # a) normal operation b) transferring data only on events important to aircraft operation c) database loads 98. A fibre optic data bus used on an aircraft a) connects non-essential systems only # b) can transmit on several channels at the same time c) can send only one message at a time 99. Light travels along a fibre optic by # a) reflection b) refraction c) dispersion 100. Manufacturers of aircraft can ensure HIRF protection by # a) designing specific avionic areas that are shielded against HIRF b) ensuring all single wires are shielded with metal conduit c) advising operators of all points susceptible to deterioration due to corrosion, moisture ingress, flexing etc. 101. How is data coupled to an ARINC data bus? a) By a capacitive pickup # b) By an inductive pickup c) By a resistive pickup 102. An AND gate output is 1 when inputs are a) both 0 b) 1 and 0 # c) both 1 103. What is hex 110 in decimal # a) 272 b) 282 c) 32

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 104. Convert the binary word 1100 to decimal a) 16 # b) 12 c) 11 105. How does MIL-STD-1533 put data onto the data bus? # a) Through the bus controller b) R1 (remote terminal) c) SSIFU (sub-system interface unit) 106. If a data message is made up of 1 and 0 it is a) analogue # b) digital c) logic 107. Convert the binary word 1110 to decimal a) 12 # b) 14 c) 15 108. What sort of gate requires two positive voltages to operate a) NOT b) OR # c) AND 109. What is the main disadvantage of a fibre optic data bus? a) Bend radius and moisture ingress at connections b) Less strong and durable when compared to twisted pair and coaxial cable # c) Expensive to install 110. When 4 binary serial counters are connected in cascade for frequency division, what division factor is required a) 4 b) 8 # c) 16 111. Magnetic deflection in a CRT is achieved by a) a sawtooth waveform # b) a trapezoidal waveform c) a sinusoidal voltage 112. Fly by Wire systems in the fully active mode, the actuators will a) both be active # b) one in active mode, one in damping mode c) both be in damping mode, awaiting control inputs 113. The parity bit in digital information is used a) for BITE programs

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b) to check the validity of data information c) to check the status of the system

114. on a Fly by Wire system, what controls the stab trim a) ELAC # b) ELAC and SEC c) SEC 115. A disadvantage of a fibre optic cable is a) shallow bend radius b) couplings susceptible to ingress of fluid # c) liable to environmental contamination of end terminals 116. ARINC 429 SDI word format is at bits a) 1 - 8 # b) 9 - 10 c) 32 117. Convert the binary number 110010 to decimal a) 80 # b) 50 c) 34 118. What is serial to parallel and vice-versa called a) Encoder/Decoder # b) Multiplex/Demultiplex c) Switching 119. What is the parity bit for on an ARINC 429 bus # a) To check for corruption during transmission of a word b) To act as a terminal gap in an emergency c) To delay the signal 120. 3 binary counters in cascade. What is the division? # a) 8 b) 16 c) 32 121. Control of software is by # a) the National Aviation Authority b) engineers c) the aircraft manufacturers 122. A typical fibre optic connector is a) F-type connector # b) coupling type, with lens fitted c) push-pull connector 123. An ARINC 429 word label format is a) binary

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b) octal c) hexadecimal

124. Which of the following is an optelectronic device? a) Triac b) Thyristor # c) Laser Diode 125. What is the advantage of a single mode fibre optic over ordinary wire? # a) Large bandwidth b) Small bend radius c) Not prone to damage 126. How many LRUs can be connected to an ARINC 429 data bus a) 120 # b) 20 c) 60 127. Convert the hexidecimal number D into decimal a) 13 b) 14 c) 15 128. Convert decimal 15 into binary a) 1101 # b) 1111 c) 1110 129. Convert 448 to hex a) 3616 # b) 2416 c) 2216 130. When will a NAND gate give logic 0 at the output? a) When both inputs are at 0 # b) When both inputs are at 1 c) When the inputs are different 131. How many LRUs can be connected to an ARINC 629 data bus # a) 120 b) 20 c) 60 132. Convert decimal 15 into hexadecimal a) E b) G # c) F

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 133. Which logic gate has this truth table A B C C B A 0 0 0 1 1 0 1 0 1 0 1 1 a) NOT # b) Exclusive OR c) NAND 134. Which logic gate can be represented as a parallel circuit? # a) OR b) Exclusive OR c) NAND 135. What is the definition of level one software? # a) Critical b) Essential c) Non-essential 136. ESDS bags are sealed by a) zip locks b) ESDS labels # c) twine (100% cotton) 137. What is 345 in binary? # a) 101011001 b) 110011001 c) 100111001 138. What are the values of an ESDS wrist strap? # a) 250 kilohms to 1.5 megohms b) 2 megohms to 5 megohms c) 2 gigohms to 4 gigohms 139. Convert 1D to binary a) 29 # b) 11101 c) 101001 140. ARINC 629 terminal transmit interval is a) unique to each terminal # b) common to each terminal c) is when all transmissions are quiet 141. Convert 2C hex to octal # a) 54 b) 44 c) 35

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 142. A fibre optic light source is normally a) a filament lamp # b) a laser or LED c) a strobe light 143. What precautions are required when removing ESDS equipment # a) Wear a wrist strap connected to an approved ground point b) Keep one hand on the airframe c) No special precautions are required 144. An ARINC 429 bus uses a) two bi-directional twin, sheathed and earthed wires # b) a twisted shielded pair of wires c) a single twin cable for each transmitter 145. The minimum requirement for a cockpit voice recorder to begin operating is a) on engine startup # b) on commencing the takeoff roll c) once established in the en-route climb 146. ARINC Communications Addressing and Reporting Systems is used to a) download aircraft status reports # b) connect the aircraft to base c) make telephone calls 147. ARINC 429 data bus systems uses a) decimal numbering b) hexadecimal numbering # c) binary coded decimal 148. with radio coupled autopilot, what are the inputs a) ADF and ILS b) ADF and VOR # c) ILS and VOR 149. B-RNAV system must be capable of a) holding six waypoints # b) displaying distance and bearing to waypoint c) reversing the waypoints for "fly-me-home" 150. The basic principle of radar is based upon a) the amount of power in the signal returned # b) the time delay between outward and returning pulse c) ultrasonic wave propagation 151. An ARINC 429 Binary Coded Decimal word occupies word bits a) 11 - 28 # b) 11 - 29 c) 1 - 8

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 152. Engine parameters are displayed on # a) ECAM b) EHSI c) CDU 153. A flight deck CRT LRU is being replaced. What does the ESDS label indicate? a) Wrist straps should be worn # b) Do not touch plug pins or leave them exposed c) Remove power before connecting 154. What systems does the ADC feed? a) Altimeter / FMS / secondary radar b) Standby altimeter/machmeter # c) Cabin pressure controller sensor / machmeter / Altimeter 155. A hexadecimal is a number to base a) 8 b) 2 # c) 16 156. An ARINC 429 system uses a a) 16 bit word over a twisted pair of wires # b) 32 bit word over a twisted pair of wires c) 20 bit word over a bi-directional bus 157. A thyristor is a device which has a) a positive temperature coefficient # b) a negative temperature coefficient c) a temperature coefficient of zero 158. When using a wrist strap, before touching the LRU the resistance should be measured from your skin to the end of the earth probe. This should be # a) more than 10 kilohms b) less than 10 kilohms c) less than 1 ohm 159. 1012 converted to decimal is a) 52 # b) 510 c) 210 160. Physical variables in quantitative forms, such as voltage or angular rotation of a shaft are # a) analogue b) digital c) binary 161. Within a 3 bit frequency cascade, division is to # a) 8

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions b) 4 c) 2 162. When is a radio altimeter active? a) Up to 10,000 ft # b) Up to 2,500 ft c) Up to 100 ft 163. Which of the following could be a primary cause of HIRF protection failure? # a) Unserviceable radio filters b) Broken or missing static wicks c) Corrosion on bonding leads 164. The binary coded decimal number 10011000 expressed as a decimal number is # a) 9810 b) 15210 c) 1522 165. The decimal number 7 expressed as a binary number is # a) 1112 b) 72 c) 1012 166. Convert 011101 binary to octal a) 25 b) 33 # c) 35 167. Manufacturers of aircraft can ensure HIRF protection # a) by designing specific avionic areas that are shielded against HIRF b) by ensuring all single wires are shielded with metal conduit c) by advising the operator of parts of the aircraft susceptible to degradation due to corrosion, moisture ingress, flexing etc. 168. An ARINC 629 characteristic is a) all LRUs can transmit at the same time b) all LRUs can transmit and receive at the same time # c) data can transmit in both directions down the data bus 169. in an ARINC 429 word string, bits 1 - 8 represent a) the source of the message # b) the monitored parameter c) the destination LRU 170. What limits the number of ARINC 429 receivers on a bus a) The speed and size # b) The parallel input impedance c) The weight

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 171. The 'fan-in' in a gate is the a) number of outputs from a gate # b) number of inputs to a gate c) number of inputs and outputs of a gate 172. Very Large Scale Integrated (VLSI) means the number of gates in a single IC is a) up to 1000 b) up to 10,000 # c) over 10,000 173. The advantage of DRAM over SRAM is a) they operate slower b) has a larger storage capacity per chip area # c) are cheaper to manufacture 174. A BYTE is usually a) a 12 bit word # b) an 8 bit word c) a six bit word 175. Data is transferred on the MIL-STD-1553B by a) bi-polar return to zero # b) manchester bi-phase c) non return to zero 176. The fibre optic cable can be identified on aircraft by its jacket colour which is # a) purple b) red c) yellow 177. For a fibre optic cable connector that is not regularly disconnected you would use the a) ceramic lens type b) ball lens type # c) butt type 178. The timebase in a CRT consists of # a) an amplifier and an oscillator b) an oscillator only c) an amplifier only 179. HIRF protection of LRUs is provided by # a) built in filters and overvoltage circuits b) internally shielded cables c) built in filters only 180. An EADI display of flight director commands are coloured a) cyan

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions b) red # c) magenta 181. Which systems does a modern ADC give information to? # a) Flight control computer, Air Data Instrument, Engine systems b) EFIS c) EICAS 182. Binary Number: 110010 a) 80 # b) 50 c) 34 183. How are engine indications sent to the FDR? # a) Via ARINC 573 b) Via ARINC 629 c) Source isolated 184. What is this truth table?

# a) AND gate b) NOR gate c) NOT gate 185. Where do the outputs from a DADC go? a) EADI b) EHSI # c) IRMP: Inertial Reference Mode Panel 186. During an EFIS screen fit a) use bonding strap # b) don’t touch terminals c) no tooling is required 187. To stop earth loops forming, you would a) leave both ends of the cable screen open circuit b) earth both ends of the cable screen # c) earth only one end of the cable screen 188. How many satellite signals are required to achieve precise 3D positioning? # a) 4 b) 5 c) 6

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 189. Binary addition of 1101 + 101101 is # a) 58 b) 61 c) 70 190. What system uses base 8? # a) ARINC 429, in dataword labels only b) ARINC 629 c) ARINC 573 191. What maintenance problems are associated fibre optics? a) Corrosion b) Earthing faults # c) Kinking and contamination of connectors 192. Who can sign for a software update? a) Design organization or the aircraft manufacturer # b) Engineer c) Chief pilot 193. What sort of gate is this?

#

a) Or gate b) NOR gate c) NOT gate

194. What creates the raster effect on a CRT? # a) Sawtooth frequency b) Sinusoidal frequency c) Trapezoidal 195. Common fibre optic use is # a) modulating intensity on direct read b) modulating frequency on direct read c) HIRF 196. An aircraft may have been HIRF affected. # a) A static wick check is required b) A bonding load check is required c) Test all radio frequencies for interference 197. The binary number 11010111 is expressed as a decimal is: # a) 215 b) 107 c) 53

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 198. The octal number 1001 expressed as a decimal is: # a) 513 b) 613 c) 713 199. with a relative humidity of 10% to 20%, if you walked over a carpet what electrostatic voltage value would you expect to see? a) 6,000 volts b) 12,000 volts # c) 35,000 volts 200. Before fitting a Printed Circuit Board you should check the a) resistance between skin and strap end plug is less than 10 megohms b) resistance between skin and strap end plug is more than 1 megohms # c) resistance between strap and strap end plug is less than 1 megohms 201. A fibre optic data bus a) can only transmit 1 message at a time # b) can transmit several messages simultaneously c) is only used for non essential messages 202. The minimum requirement for an aeroplane CVR is a) from power on # b) from engine start c) from beginning of take off roll 203. on an ARINC 629 data bus, the maximum amount of current-mode couplers per data bus is a) 46 # b) 120 c) 64 204. To connect a LRU to the data bus # a) a current mode coupler, serial interface module and terminal controller is required b) current mode coupler, terminal controller and a production break is required c) a terminal controller and interface module only is required 205. A current-mode coupler contains an E-Core assembly. The purpose of the E-Core is to # a) couple the signal to the data bus b) provide effective screening of the signal through the current-mode coupler c) enable easy access for monitoring of the signal 206. The ARINC 429 low rate of transmission is # a) 12-14 Kbits/second with high of 100 kBits/second b) 12-14 Mbits/second with high of 100 Mbits/secon c) 100 kbits/second with high of 12-14 Mbits/second

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 207. A D to A converter is required to produce an output range of 0 to –10V. This can be achieved by a) A non inverting op amp connected in parallel with output # b) An inverting op amp connected in parallel with output c) A differentiator with a 100 Kilohm feedback resistor 208. A D to A converter would use a precision amplifier to # a) Ensure that the output voltages remain accurate b) Ensure that the input voltage remains accurate c) Compensate for the variation of the feedback resistor with temperature 209. A given transducer provides a voltage which corresponds to true heading. This voltage can be converted to 'bits' by using a a) commutator b) digital to analogue converter # c) analogue to digital converter 210. The output of a NOT gate is logic 1. The input is a) logic 1 # b) logic 0 c) both logic 1 211. An ARINC 629 bus cable is a twisted pair of wires with a) a 130 ohm resistor at one end b) a 230 ohm resistor at one end # c) a 130 ohm resistor at both ends 212. An ARINC 629 stub cable # a) connects bi-directional data between the LRU and current mode coupler b) connects single directional data between the LRU and current mode coupler c) connects bi-directional data between two LRUs 213. Care must be taken when installing ARINC 629 cables into bus panels, damage to cables can cause a) arcing of high voltage signals b) standing waves. # c) corrosion of the conductor 214. An aircraft data bus system a) cannot use both ARINC 629 and ARINC 429 data buses. b) can use both ARINC 629 and ARINC 429 as they are compatible. # c) can use both systems, ARINC 629 and ARINC 429 via system card files and signal gateways 215. An Inertial Navigation System (INS/IRS) computes distance from acceleration by a) a simple integration

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b) a differentiation followed by an integration c) two successive integrations

216. Before the aircraft is moved from the loading pier the pilot must # a) insert the latitude and longitude of the pier into the IRS b) set the altitude to be fed into the INS c) insert the longitude and latitude of the first waypoint into the INS 217. A 12 bit 16 Channel encoder will use a multiplexer with a) 2 wire series address line b) 3 bit parallel address line # c) 4 bit parallel address line 218. An A to D converter uses successive approximation to a) increase resolution # b) increase speed c) increase accuracy 219. An R-2R D to A converter uses # a) two values of resistors whose precision is not important b) two values of precision resistors c) resistors whose values are logarithmic 220. A fiber optic cable to LRU connector should be connected a) using torque-loaded pliers b) hand tight only # c) very carefully to ensure alignment and reduce light loss 221. An IRS has a) accelerometers fixed to the airframe and gyros on a stable platform # b) accelerometers and gyros fixed to a the airframe c) accelerometers on a stable platform and gyros fixed to the airframe 222. An IRS system requires data for wind computation from # a) central Air Data Computer b) satellites c) Doppler System 223. The FMS carries out a Rho/Theta navigation function, the purpose of this is to # a) update the IRS system with an accurate position fix of latitude and longitude b) to update the EMS with the new lateral flight profile for the flight plan c) to update the VOR and DME systems with an accurate position fix 224. The FMS is updated a) by the aircrew by reference to the Tech Log b) automatically by update data from the ACARS # c) by an aircraft engineer updates the system either by a magnetic tape or floppy disc

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 225. Pitch Control of a fly by wire system is achieved by a) elevators only # b) stabilizer and elevator c) stabilizer only 226. In a fly by wire system, if the pilot control input is derived from a side stick controller: a) control surface feedback is fed to the side stick # b) there is no control surface feedback to the side stick c) there will be only control surface feedback to the side stick after a computer failure 227. in memory using multivibrators, when power is switched off the data will a) still be available on power up # b) be lost c) automatically be downloaded 228. The resistance of the wrist strap used as part of anti static precautions should be a) 0 - 200 ohm # b) 250 kilohm - 1.5 megohm c) 20 megohm - 200 megohm 229. What is the function of a status register in a microprocessor? # a) To indicate the status of the processor b) In the ALU, to store the position of the program during an interrupt c) To synchronize the clock pulse 230. What is the advantage of EPROM over fusible link? a) Cheaper to produce # b) Can be re-programmed c) Does not need refreshing 231. A basic IRS platform has a) 3 accelerometers and 2 laser gyros b) 2 Accelerometers and 3 laser gyros # c) 3 accelerometers and 3 laser gyros 232. What must be entered into the IRS before the aircraft can be moved? # a) Present position b) Flight plan c) Cruise height 233. The FMS Operational Data Base is a) updated once a month # b) is fed with information on aircraft weight, cruise altitude and cost index before take off c) needs no update information

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 234. Control surface feedback is fed back to # a) the Flight Control Computer only b) the Flight Control Computer and side stick controller c) the side stick controller only 235. The function of a commutator is to a) convert from analogue to binary form # b) provide a sampling in sequence of a number of parameters c) provide continuous availability of all parameters connected to the system 236. When the voltage that represents a logic 1 state is less than the voltage that represents a logic 0 state, the logic being used is a) either positive or negative b) positive # c) negative 237. The output of an AND gate having two inputs A and B is logic 1. The two inputs will have the logic states of a) A = 0, B = 0 # b) A = 1, B = 1 c) A = 1, B = 0 238. Registers are used in digital computers to a) store bits of information in a permanent memory # b) store a limited amount of information on a temporary basis c) keep a count of operations completed 239. What is 0111000012 in Octal? a) 28110 b) 2258 # c) 3418 240. ARINC 629 is used for # a) normal flight b) emergency only c) a backup to ARINC 429 241. Testing of HIRF on aircraft systems is done a) by periodically listening for interference on all systems # b) at and during production and testing (initial certification) c) only after a report of radio interference 242. How are earth loops prevented from forming? # a) Ground only one end of the cable screen b) Ground both ends of the cable screen c) Ground neither end of the cable screen 243. When carrying out a bonding check on a surface protected by anodic film # a) the anodic film should be removed locally to ensure a good contact

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions b) the film is conductive so no preparations are required c) add a bonding factor to the result of the test to account for the resistance of the anodic film 244. The accelerometer output in an INS/IRS is a) integrated twice to give velocity # b) integrated twice to give distance c) integrated once to give distance 245. An INS/IRS Battery Unit provides # a) standby power when airborne and on the ground b) standby power only whilst in flight c) standby power only on the ground 246. The FMS Navigation Data Base must be updated a) once a month # b) every 28 days c) before each flight to establish the flight plan 247. If a fly by wire actuator loses hydraulic power the control surface will a) automatically move back to the neutral position b) remain rigid in the failure position # c) remain in the failure position but may move due to aerodynamic pressure 248. The output of an OR gate having two inputs A and B is logic 0. The two inputs will have the logic states of # a) A = 0, B = 0 b) A = 1, B = 0 c) A = 0, B = 1 249. When clamping cable looms containing co-axial cables # a) avoid distortion to the co-axial cable to maintain the dielectric constant b) distortion of the outer sheath is allowed providing the inner cable is not affected c) the clamps must be no more than 1 metre apart 250. When incorporating an aerial cable it must be a) in the centre of the other wires b) outside the other wires for easy access # c) positioned separately from the loom 251. Some of the advantages of fiber optic cable over copper cable are a) non conductive, easy to manufacture and assemble, higher bandwidth b) smaller size and weight, non conductive, more rugged, higher security # c) non conductive, higher bandwidth, higher security, smaller size and weight 252. When carrying out airframe bonding checks as part of a program of HIRF prevention the airframe bonding resistance should be less than

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a) 50 milliohms b) 100 milliohms c) 1 ohm

253. LCD screens are driven by # a) ac voltage b) variable current dc voltage c) fixed current dc voltage 254. IRS alignment # a) takes up to 10 minutes and the present position can be entered at any time during alignment b) takes up to 10 minutes and present position must be entered before alignment. c) takes up to 10 minutes and the previous flight shut down present position is used for the alignment 255. A fault light appears on the IRS Mode Selector Unit during the alignment sequence. The correct action is a) immediately switch off and select the standby system. # b) select HDG/STS on the Inertial System Display Unit (ISDU), observe the action code in the right alpha/numeric display c) refer to the warning display on the EICAS/ECAM system. 256. EFlS systems have two control panels, their purpose is a) to provide display control by one control panel whilst the other provides a standby b) one for the EADI display and one for the EHSI display # c) one to control the type of EFlS display and the other to select the source of the information being displayed 257. A FMS has a total of how many Data Bases a) 1 # b) 2 c) 4 258. Fly by wire High Speed protection is a) to prevent high speed stall b) to increase the pitch angle as speed increases # c) to prevent tuck under 259. In a single mode fibre optic cable a) several waves travel down the cable # b) the diameter of the cable is dependent on the wavelength of the light used c) the distortion of the signal occurs is dependent on the length of cable 260. A semiconductor which emits photons and releases electrons when stimulated by photons is called a) an LED

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b) a photodiode c) a laser diode

261. An IRS Laser gyro provides # a) detection of the rate of movement about an aircraft axis b) detection of the earth’s rotation to establish true north c) detection of the earth’s gravitational force to establish true north 262. A Liquid Crystal Display (LCD) has the advantage over a CRT because a) it displays more colours b) it requires less servicing # c) it requires no cooling 263. The left and right cockpit displays a) are supplied from separate Symbol Generators at all times b) are supplied from the same Symbol Generator # c) will only be supplied from the same symbol generator when all other symbol generators have failed 264. A single failure of a fly by wire control surface computer will a) cause the system to revert to an alternate law of operation b) cause the system to revert to a direct law of operation # c) not have any operational effect on the system 265. An encoder changes a) analogue to digital b) digital to analogue # c) data from one format to another 266. An encoder using Grey code # a) changes analogue to digital b) changes analogue to binary c) changes digital to analogue 267. What is the Low Speed transmission rate for ARINC 429? # a) 12 – 14.5 kbits / second b) 100 kbits / second c) 120 kbits / second 268. What is this symbol:

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a) Exclusive AND gate b) Exclusive OR gate c) Exclusive NOR gate

269. What Logic Gate does this switch circuit indicate?

#

a) AND gate b) OR gate c) NOR gate

270. What is the effect of a level 1 software failure? a) Significant reduction in safety margins b) Large reduction in safety margins # c) Loss of aircraft and / or fatalities 271. Ribbon cables affected by mutual impedance and current loop leakage are protected by a) earthing each conductor # b) earthing each alternate conductor c) wrapping the complete ribbon in an earthed shield 272. What is the definition of baud rate? # a) 1 bit per second b) 1 byte per second c) 1 word per second 273. An RS flip-flop with Q at 1 is said to be a) reset # b) set c) zero 274. What is the Boolean Algebra for the XOR Circuit below?

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions a) #

b) c)

275. What does the logic circuit below represent?

#

a) Half adder circuit b) Full Adder Circuit c) Multi-bit adder

276. The release of a photon by another photon is an example of a) a zener diode # b) an LED c) a photo diode 277. When a JK flip flop is used as a memory device, what type of memory would it be a) non-volatile b) read-only # c) volatile 278. Once an ARINC 629 LRU has transmitted a message it will wait how long before transmitting again? a) Until the end of the synchronization gap. # b) Until the end of the transmit interval c) Until the start of the terminal gap 279. How is the word label 206 written in ARINC 429? a) Decimal 206 b) Binary 11000110 # c) Octal 01100001

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 280. What is ARINC 561 used for? a) Flight Data Recorder systems b) Fly by Wire systems # c) Inertial Navigation Systems 281. What are the outputs from digital clocks used for? a) VOR, ILS and DME # b) Flight data acquisition unit, Flight management computer and Voice recorder c) Weather radar, TCAS and ACARS 282. What does a fibre optic star connection do? # a) Provides direct point-to-point services to units on dedicated lines emanating from the central hub b) Provides a continuous loop of fibre interconnecting all nodes c) Shares a common bandwidth of a common cable 283. What is the purpose of the ALU? a) To convert serial into parallel data b) To store data being used by the CPU # c) The part of the CPU unit where arithmetic & logic operations are carried out 284. Which logic gate has both inputs ‘high’ to get an output? a) NAND gate b) XOR gate # c) AND gate 285. Which would have the least components? # a) ALU b) CPU c) LSI 286. How many address lines would be needed for an 8 line MUX? a) 4 # b) 3 c) 2 287. in a MUX, how is parallel converted to serial? # a) By way of a shift register b) By way of a demultiplexer c) By way of an encoder 288. If a magnetic field is parallel to the X plates in a CRT, which way will the beam move? a) Diagonally b) Vertically # c) Horizontally 289. What would you expect to see displayed on an EADI display?

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a) Flight director command bars, slip indicator, rate to altitude & autoland b) Compass heading, selected heading and VOR c) Course information, weather radar, way point alert and bearing pointers

290. a) b) c)

The binary number 10101000111001012 in hexadecimal is: 22BC16 A8E516 FFFF16

291. A fibreoptic lens type coupling with lens and integral LED compared to an end-fire coupling is # a) more efficient b) less efficient c) equally efficient 292. An analogue to digital converter is as accurate as # a) the sampling rate b) the frequency c) the amplitude 293. A digital to analogue converter that requires the output to range between 0v and -10v would have a) a non-inverting amplifier in parallel with the output line # b) an inverting amplifier in series with the output line c) a non-inverting amplifier in line with the output with a resistor to ground 294. An LED display is a) red and green # b) monochrome only c) high definition 295. An EFIS ADI display will show along with pitch and roll a) flight director bars, autoland, compass rose, altitude b) flight director bars, autoland, altitude, range to altitude, decision height # c) decision height, autoland, rad alt, altitude 296. A full operation system BITE check will a) but will not move the controls b) as well as checking full system and will move the controls to their stops # c) as well as checking full system but will not move the controls to their stops 297. If on a flight deck EFIS system all the displays were missing one bit of information this is most likely to be a) the symbol generator and display # b) the input sensor bus and display controller c) the display controller and symbol generator

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 298. A arinc data word is bits 11-29, if bits 11-18 are patched which of the following would be the LSB bit # a) 19 b) 29 c) 21 299. What is a band? a) A block of data # b) A bit of data c) A byte of data 300. Passive sensors in fibre optics a) require power for the processing signal before they send them down the fibre optic # b) require no power and they do not process signals c) process the signal but do not require power 301. An LCD display uses what type of power supply? # a) Continuous AC b) Variable level DC voltage c) DC voltage 302. Fibre optic data bus links are # a) bi-directional b) one way data buses c) simplex 303. 0011011000101001 when transferred to computer language this information can be a representation of a) binary, octal or decimal numbers b) hex, octal and binary numbers # c) hex, octal and decimal numbers 304. In a bi-stable memory circuit # a) the memory is lost as soon as power is removed b) the memory is retained indefinably c) the memory needs to be refreshed constantly, even when power is on 305. in an analogue to digital converter, the input voltage # a) stays on constantly b) is switched by the digital input c) is intermittent 306. In an RS flip flop output is one. This means it is # a) set b) reset c) intermediate 307. ARINC 629 utilizes a) full duplex

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b) half duplex c) simplex

308. Optical fibre losses are due to a) absorption only # b) absorption, scattering and reflection c) radiation, absorption and reflection 309. The cone of acceptance is measured between # a) longitudinal axis of the core and the outer angle b) the two outer angles c) the diameter of the core 310. An R-2R Converter has values or resistance a) whose precision are accurate # b) whose relative precision are accurate c) whose precision are not accurate 311. An ALU is an example of # a) LSI b) SSI c) MSI 312. What does 1 represent in an analogue system? # a) Switches closed, magnetised b) Switches open, unmagnetised c) High frequency 313. A centralised monitoring computer system is used a) to test system during flight and for BITE test of systems on the ground using a carry on control unit # b) to test systems in flight and on the ground using a centralised on board control unit c) testing systems on the ground only 314. A signal in an ARINC 629 system uses a) a pair of wires per transmitter unit # b) a twisted pair of wires or fibre optics c) a single wire 315. A beam deflection on EFIS displays are # a) electromagnetism b) electrostatic c) solid state 316. A nand and nor to become a not gate have # a) inputs connected together b) inputs inverted c) outputs inverted

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 317. An in-series ARINC 429 system transmits using a) wave dividing multiplexing # b) time dividing multiplexing c) encoder 318. Fibre optic cables use a) reflective outer shell # b) refractive outer shell c) reflective inner shell 319. A sinusoidal circular time constant produces what output? # a) 90 degrees out of phase b) 180 degrees out of phase c) In phase 320. A terminal controller a) transmits only when addressed b)is repetitive transmitting # c) will transmit only once during each transmit interval 321. What is the advantage of series over parallel message sending? a) Quicker b) More information sent # c) Only one pair of conductors 322. The number of LRUs which transmit/receive on ARINC-429 is dependent upon a) size of S.D.I b) speed of transmission & size of aircraft systems # c) parallel input impedance 323. In fibre optic cable, signals are separated by # a) active optic filter b) passive optic filter c) low pass filter 324. In an EFIS display, the lines, Scales, Indicator and Synoptic are generated by a) synoptic scan # b) stroke scan c) raster scan 325. Speed of computer process information depends upon a) the size of the programme # b) the time period to access the memory c) the external inputs to the system 326. A typical example of a mass storage memory device which "write once" and "read many" is # a) a CD Rom

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions b) an IC c) a magnetic tape 327. When handling PCB's labelled ESDS, what precaution are taken? # a) Isolate electrical power before installing on Aircraft b) First earth with aircraft then to it c) Do not touch its pins as copper contamination can occur 328. A computer consist of at least the C.P.U and # a) memory and input & output port b) register section, ALU, timing and control section c) memory, ALU, input & output port 329. Electromagnetic compatibility is achieved by # a) shielding, screening, earthing, bonding and interference filters b) enclosing the system with same frequency and strength of which screening is done c) coating in a conductive paint 330. The supply to an LCD is # a) AC b) current restricted DC c) voltage restricted DC 331. The method of producing (white) lines for aircraft symbols, V/S scale etc. on an EADI is by # a) stroke scan b) raster scan c) trapezoidal input 332. In modern aircraft, the output from the clock is used a) to synchronise the signals on the control bus # b) give GMT details to the flight recorder and other systems c) to provide a clock pulse for CRT 333. Audio sounds recorded digitally a) are not as accurate due to clipping and input errors # b) are superior quality and "data preservation" c) are narrow bandwidth 334. When carrying out HIRF maintenance on aircraft, the max resistance is a) 1 milliohm b) 1 ohm # c) 0.05 ohms 335. A computer message 3B4 is a) binary b) octal # c) hexadecimal

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 336. One of the ARINC 429 formats is a) hexadecimal # b) BCD c) octal 337. When does voice data recording commence? a) On engine start # b) From aircraft take off run c) After take off when airborne 338. What is 54 octal in hexadecimal # a) 2C b) 4F c) 2F 339. A heading reference of 320 degrees in a word label format would be written as a) 101010001 # b) 11010000 c) 01000111 340. within an EFIS display system, all displays have 1 bit of information missing. What would be the most probable cause? # a) Symbol generator and sensor input b) Display controller and sensor input bus c) Display controller and symbol generator 341. A computer using RAM would utilise a) a compact disc # b) an integrated circuit (chip) c) magnetic tape 342. With a j-k flip flop which is the output set # a) q = 1 b) q = 0 c) either 343. If the glideslope pointer is below the centre mark the aircraft is a) on the glideslope b) below the glideslope # c) above the glideslope 344. 2D in decimal is # a) 45 b) 43 c) 41 345. The operational data base of the FMS may have to be modified in flight a) by the pilot b) automatically by the DADC

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c) It cannot be modified in flight

346. An LED will emit light when # a) it is forward biased b) it is reverse biased c) either forward or reverse biased if a sufficient level of ac voltage is applied 347. On an EFIS system the weather radar is displayed on a) the EADI # b) the EHSI c) the FMC CDU 348. CADC outputs are a) altitude, vertical speed, IAS, mach no b) altitude ,vertical speed, angle of attack, TAT, SAT # c) altitude, vertical speed, TAS, CAS, mach no, SAT, TAT 349. Data is converted from serial to parallel and parallel to serial by a) a parallel register # b) a shift register c) a synchronous counter 350. A group of bits transmitted at the same time is a) a clock signal # b) parallel data c) serial data 351. A typical characteristic of a CMOS is # a) low power dissipation b) high voltage handling c) high power dissipation 352. If one EICAS CRT fails # a) the remaining CRT will display primary EICAS data b) the FMS CDU will display the failed CRT data c) the standby CRT will automatically take over 353. 84 decimal in hexadecimal is # a) 54 b) f4 c) 5f 354. EADI displays # a) pitch and roll attitudes b) heading and weather radar c) pitch, roll and waypoints 355. on an EHSI in weather radar mode, a severe storm would be shown as a) orange areas with black or yellow surrounds

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b) red areas with black surrounds c) blue areas with white background

356. Variations in light on EFIS displays are compensated for by # a) integrated light dependant resistors in the display compensating for each display individual b) An external light dependant resistor mounted on the flight deck compensating for all displays in a parallel-parallel format c) manual adjustment by flight crew on EFIS controller 357. The input bus into a central processor unit is a a) one way bus # b) bi directional bus c) two way bus 358. A method used in modern aircraft for reporting in flight faults to an engineering and monitoring ground station is a) TCAS II # b) ACARS c) TAWS 359. A CRT display has the advantage over an LCD display by a) brighter clearer output b) more energy efficient # c) large viewing angle 360. Most fibre optic connectors are designed so a) the receptacle has to torque to a designated torque to ensure correct alignment # b) the connectors can not be over tightened c) the connector can not be replaced on the aircraft 361. The self test function on an EFIS system can be tested a) in the air only # b) on the ground only c) in the air and on the ground 362. Each of the symbol generator outputs in an EFIS system can be # a) displayed of each individual display b) only no. 2 can be displayed on the no.1 c) can not be interchanged 363. An AND gate with inverted inputs and an inverted output is equivalent to a) an AND gate # b) an OR gate c) a NOR gate 364. Logic gates internal operating mechanisms are produced from a) thin film resistors # b) transistors

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions c) diodes 365. To display a circle on a CRT you use a) 2 sine waves 180 degrees out of phase # b) 2 sine waves 90 degrees out of phase c) 2 square wave 90 degrees out of phase 366. The light source used in fibre optics is a) higher bandwidth than visible light # b) lower bandwidth than visible light c) visible light 367. When the power is removed from a bi-stable memory device, it's memory will # a) be lost indefinitely b) be saved indefinitely c) downloaded to memory 368. BITE tests are inhibited for ground use during # a) take-off b) gear retraction c) forward motion 369. Software changes come under the responsibility of a) the national aviation authority # b) the aircraft constructor c) the engineer 370. A multiplexer # a) takes many signals in and converts it to a serial transmission output b) takes one signal in and converts it to a parallel transmission output c) takes many signals in and puts these in a parallel transmission on the output 371. The CPU consists of a) register and arithmetic logic unit only # b) ALU, timing and control section, register c) register, timing and control section only 372. The ARINC 429 system uses the following system to transfer data a) non return to zero b) harvard bi phase # c) bi-directional return to zero 373. Which of the following ARINCs are bidirectional? a) 429 # b) 629 c) 573 374. Data is transferred on the MIL-STD-1553B by using

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a) bipolar return to zero b) manchester bi-phase c) non return to zero

375. The general arrangement of ARINC 629 includes a) current mode coupler, data bus cable only b) data bus cable, stub cable, voltage mode coupler # c) data bus cable, current mode coupler, stub cable 376. To deflect the beam of a CRT horizontally, coils are placed on the neck of the tube a) one on the side, one at the bottom b) each side # c) top and bottom 377. During flight (non fault conditions) the EICAS system displays on the lower CRT # a) secondary engine parameters b) synoptic display c) flight phase page 378. Who can design new software? # a) BCAR section A8 approved company b) BCAR section A1 approved company c) The CAA 379. Data bus cables are terminated using # a) 130 ohms resistor b) 100 ohms resistor c) 25 ohms resistor 380. Modern aircraft with electronic displays would display information on airframe and engine on which system? a) Flight management system # b) Electronic centralised aircraft monitoring system (ECAM) c) EADI 381. The Flight data recorder starts recording a) after take off b) on aircraft roll out from stand # c) after the first engine has started 382. Data to flight data recorder can be taken form a communal data bus if a) it goes directly to it b) the power is within flight data recorder limits # c) if source isolation has been considered 383. In ARINC 429 data field is bits 11 to 28. If the bits 11 to 18 had pad bits, the L.S.B. Of the data would be # a) bit 19

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions b) bit 11 c) bit 28 384. The BCD data field of ARINC 429 is contained within bits a) 1- 8 # b) 11- 29 c) 11- 28 385. After attaching a wrist strap to you wrist (which is connected to aircraft ground), prior to removal of ESDS equipment, the resistance measured a) between the strap and the pin ground must be >10 Megohms # b) between your skin and the pin ground must be <10 megohms c) between the strap and the pin ground must be <10 meghms 386. The major source of degradation of HIRF protection is a) corrosion b) damage to static wicks # c) radio filter break down 387. The resistance of the magnetic coils of a C.R.T. Is offset by using # a) trapezoidal voltage b) constant voltage c) saw tooth voltage 388. If the magnetic deflection plates produce a magnetic field which is parallel to the horizontal then the trace is deflected in a) horizontal axis b) circular motion # c) vertical axis 389. Light transmission in a fibre optic cable is due to # a) repeated internal reflection b) refraction of the light c) defraction of the light 390. The name given to the joining of two fibre optic cables by aligning them carefully and bringing them into close proximity of each other is a) Fusion # b) End to end c) Lens Coupling 391. In a fibre optic cable a) only one data signal can be sent down it at any one time # b) multiple data signals can be sent down it at one time c) data can only be sent in one direction 392. A logic 1 may be represented in an analogue system by (where Q is an output of a latch / flip-flop) a) switch open / light on / Q b) switch closed / light off / Not Q

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c) positive / magnetised / Q

393. A central fault display system should be available through a) a bite test # b) a easily accessible multifunction control display unit c) a central bite test box with clear LED indications 394. An analogue to digital converter where it counts up to binary state equal to the analogue in put and then back down when this is reached is a a) successive approximation counter # b) a tracking ramp type converter c) flash type converter 395. Transistors are used in a current triggered D to A device to a) switch on the input b) switch of the inputs # c) change the state of the inputs 396. Radio altitude is displayed on a EFIS system a) on the Electronic horizontal situation indicator # b) on the electronic artificial direction indicator c) on the RMI 397. A flight data recorder should be capable of recording a) the last 25 hours b) the last 25 hours of aircraft flight # c) the last 25 hours with engines running 398. Op amps generally used in ADCs and DACs are normally # a) high input impedance, low output impedance b) high input impedance , high output impedance c) low input impedance , how output impedance 399. Magnetic materials are used in a) ROMs only # b) some RAMs c) EPROM 400. The pins on an op amp are numbered a) clockwise # b) anticlockwise c) cross ways 401. A parallel register # a) reads each bit to be stored simultaneously b) requires a clock pulse for each bit c) reads the stored data when logic 0 is applied to the read line 402. HIRF protection is in the order of # a) hardened skin and protecting wires / LRUs

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions b) bonding as many parts of the aircraft as possible and a maximum resistance of 0.05ohms c) periodically turn off components whilst radio transmitting 403. 16 hexadecimal converted to decimal is equivalent to a) 38 b) 48 # c) 22 404. To get logic 1 using this gate

#

a) A or B = 1 b) A and B = 1 c) A and B = 0

405. What logic gate would this circuit represent?

#

a) NAND Gate b) NOR gate c) AND gate

406. Decimal 10 converted to binary is a) 1111 b) 1001 # c) 1010 407. What systems uses base 10? # a) Decimal b) Digital c) Octal 408. What systems use base 16? a) Octal b) BCD # c) Hexadecimal 409. EADI pointers, dials and engine data is produced using # a) stroke pulse b) raster scanning c) electromagnetic waves 410. Fibre optic cables consists of a silica glass core and # a) refractive outer cladding

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions b) reflective outer cladding c) reflective inner cladding 411. The waveform to the coil of a CRT is # a) trapezoidal b) ramp c) analogue 412. Analogue logic 1 is a) closed switch, Logic Q=0 # b) closed circuit, Logic Q=1 c) open circuit 413. ARINC 629 is transmitted using # a) fibre optics or twisted pair of wires b) single wire for each transmitter c) SWG 28 wire 414. BITE for ground use only is switched off a) when breaks are released b) when undercarriage up # c) on take-off 415. Fibre optics relies on a) fibre absorbing light # b) light reflecting off cladding c) light escaping cladding 416. The "light" emitted from a LED used within a fibre-optic system will have a wavelength # a) slightly longer then that of visible light b) slightly shorter then that of visible light c) equal to that of visible light 417. Binary coded decimal (BCD) format has a minimum of # a) four "0s" or "1s" b) 2 lots of four "0s" or "1s" c) 3 lots of four "0s" or "1s" 418. A simplex system has # a) 1 transmitter and multiple receivers b) 1 bus controller and 1 remote terminal c) 1 bus controller and multiple receivers 419. Fibre optic cable over copper cable has the following advantages a) non-conductive, easier to manufacture and assemble, greater bandwidth # b) non-conductive, greater bandwidth, greater signal security c) greater bandwidth, greater signal security, more robust

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 420. a EFIS system ADI displays pitch, roll a) autoland, altitude, compass rose and flight director bars b) autoland, decision height, range to altitude and flight director bars and slip indicator # c) autoland, rad alt, decision height and slip indicator 421. What is the Hexadecimal number F86 in Binary? # a) 111110000110 b) 111110000001 c) 3974 422. What is 11000012 - 1011002? a) 1101112 b) 100011012 # c) 1101012 423. During normal functioning of an ECAM system the engine data shown on the Engine/Warning display comes from the a) EFIS channel of DMC3 # b) ECAM channel of DMC1 c) ECAM channel of DMC3 424. To create a bi-directional communications link within an ARINC 429 system a) only one databus is required # b) two databuses are required c) four databuses are required 425. Using I.N.S. an aircraft flies a) course directed by ground station # b) great circle route c) rhumb line 426. What warnings can an FMS provide? # a) Discrete warnings b) Spurious faults c) Ground faults only 427. Aircraft heading (HDG) is a) the angle between True North and the desired track b) the angle between True North and the actual track # c) the angle between True North and the longitudinal axis of the aircraft 428. For an IRS System to pass the ‘Alignment System Performance Test’ the a) entered present latitude and longitude must agree with the latitude and longitude at last power down b) the No 1 and No 2 must both have the same latitude and longitude present position entered # c) the latitude entered must be within given limits of the latitude computed by IRU

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 429. The accepted error from INS / IRS is a) 2 miles / hour + 3 miles b) l mile / hour + 3 miles # c) 3 miles / hour + 3 miles 430. Control Display Unit (CDU) selection of TKE (Track Angle Error), displays a) distance perpendicular from the selected track # b) difference in degrees that the aircraft is to the right or left of the desired track c) difference in degrees from True North in a clockwise direction from the desired track 431. in the EICAS system, when is the maintenance mode available? a) On the upper and lower screens - only available on the ground # b) Lower screen only - only available on the ground c) In flight 432. On a modern aircraft when are BITE checks carried out? a) When BITE selected b) After engine shut down # c) Continuously when system is in use 433. What causes the X and Y beam deflections in an EFIS CRT display? # a) Electromagnetic b) Electrostatic c) Either 434. in an IN system, the purpose of the stable platform is to # a) prevent unwanted acceleration affecting the accelerometers b) provide attitude reference c) stop the gyros from toppling 435. The three accelerometers on a stable platform are mounted a) parallel to each other # b) orthogonally c) 12Oo apart 436. An IN system requires data from the a) doppler system b) satellites # c) air data computer 437. XTK (cross track) is the a) angle in degrees that the aircraft track is left or right of desired track b) actual track across the earth’s surface # c) perpendicular distance from the desired track 438. The output of an INS can be fed to

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a) vertical speed indicators b) attitude indicators c) altimeters

439. The three accelerometers on a strapdown platform are mounted a) parallel to each other # b) 90o to each other c) 120o apart 440. Gyro-compassing is the term used for a) self-alignment in azimuth b) self alignment in the vertical # c) use of the gyro-magnetic compass system to align the platform 441. Centralized Aircraft Monitoring System operates to a) perform in-flight and ground tests of aircraft systems by carrying out a BITE # b) give red warnings and amber cautions to display system status c) perform in-flight BITE only 442. The control of the speed or rate that the F/D Command bars move can be controlled by a) position feedback # b) rate or velocity feedback c) amplifier gain 443. The Centralized Aircraft Monitoring System uses the maintenance mode of operation a) in the air only # b) on the ground only c) either ground or air 444. Why does an ARINC databus system send data to LRUs in series? a) More information can be sent b) Takes less time # c) Saves weight 445. Can an LRU transmit and receive on more than one 629 bus? # a) Yes b) No c) Only if paralleled 446. ARINC 629 LRUs transmit a) when addressed # b) when terminal gap is sensed c) when signal gap is sensed 447. How is multiplication achieved in an ALU? # a) by addition b) by subtraction

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions c) by coupling 448. What is the function of a status register? # a) To indicate the status of the microprocessor b) To store a program during an interrupt c) To synchronise the clock pulse 449. An ADC uses advance approximation to a) increase resolution # b) increase speed c) increase accuracy 450. A DAC uses a precision amplifier to # a) ensure the output voltages remain accurate b) ensure the input remains accurate c) compensates for the variation of the feedback resistor due to temperature 451. A BCD word occupies bits 11-29, if 11-15 are filled with padders then the LSB of the word will be # a) 16 b) 29 c) 11 452. If part of a display is lost on a CRT, this could be due to # a) an inoperative symbol generator or input sensor b) an inoperative symbol generator or control panel c) loss of power to the CRT 453. To reduce HIRF on radio equipment a) periodically check bonding leads for condition # b) ensure all static wicks are in place c) transmit on all radio frequencies to determine which frequencies are causing the interference 454. When a BITE test is carried out on a system with moving parts it should be a) carried out without operating moving parts b) carried out ensuring all moving parts are operated and taken to there stops # c) carried out ensuring all moving parts are operated but not to there mechanical stops 455. A simplex system has # a) one transmitter, many receivers b) a bus controller and separate controller c) one transmitter, one receiver 456. The smallest operation of a CPU is # a) the timescale

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions b) the processor sub-cycle c) the processor cycle 457. in a fibre optic system, different light frequencies are separated by # a) an active filter b) a passive filter c) a star network 458. The most common CRT for an EFIS system screen is a a) electrostatic b) electromagnetic # c) combined 459. Sensors in a fibre optic flight control system a) require power for processors # b) do not require power c) require processing to give output 460. An accuracy amp is used to # a) give output at required level b) compensate for temperature variation c) make output between 0 - 5V 461. L.E.D.s can give a) high definition displays b) red and green displays only # c) monochrome displays only 462. Fibre optic systems can transmit data in a) one direction only b) in two directions # c) both directions at the same time 463. When handling a PCB you should ensure that # a) electrical power is isolated b) ground yourself first to aircraft then PCB c) ensure you do not touch the ends so that copper contacts do not become contaminated 464. For large bandwidth high-speed fibre optic transmission what sort of cable would you use? # a) Single mode b) Graded index c) Step index 465. In an R-2-R ladder converter the values of resistors a) are precise # b) do not need to be of precise values c) only the first resistor need to be precise

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 466. In fibre optics the wavelength of the light is a) less than visible light # b) more than visible light c) equal to that of visible light 467. What is the advantage of an ILD over an LED when used as a light source in fibre optics a) higher bandwidth # b) lower frequency range c) lower intensity 468. A typical example of a mass storage device is # a) CD ROM b) IC c) magnetic tape 469. A typical example of an IC is a) ALU # b) CPU c) dip switch 470. A circular time constant produces what sort of output? a) in phase b)180o out of phase # c) 90o out of phase 471. Speed of light in a fibre optic fibre a) is always the same no matter what material it is # b) is never greater then the speed of light in free space c) increases if it passes through material of higher refractive index 472. A device, which converts serial to parallel and parallel to serial for arithmetical functions, is a a) Multiplexer and De-Multiplexer # b) Shift Register c) Parallel to serial and serial to parallel converter 473. In an Arinc 429 Word label-representing heading is 320, this is represented in bits 1-8 as a) 01101000 b) 01011001 # c) 00001011 474. What would be the outputs if A=0 B=0 C=1

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#

a) 0, 1 b) 1, 1 c) 0, 0

475. What would be the outputs if A=1 B=1 C=0

#

a) 0, 1 b) 1, 1 c) 1, 0

476. The angle of incidence of a beam of light in a fibre optic cable will be a) twice that of the cone of acceptance # b) approximately half that of the cone of acceptance c) parallel with the end of the cable 477. A fibre optic cable is connected to a unit that will not be frequently disconnected. The preferred type of connector to be used is a a) Ball lens type # b) Butt type c) Quick disconnect type

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 478. A cyclic test (watch dog) should be performed for ECAM a) during power up # b) during in-flight c) MCDU 479. How is the symbol generator detecting the program error # a) looking at the odd parity without error b) looking at the even parity without error c) check sum bites for error detect 480. What is EPROM? # a) erasable programmable read only memory b) enhanced programmable read only memory c) erasable programming read only module 481. A CRT is # a) electromagnetic b) electrostatic c) solid state i 482. What is used for the power of 10? a) octal b) digital # c) decimald 483. What is 44 in hexadecimal? # a) 2c b) 2d c) 2F 484. What is octal 33in hexadecimal? a) 22 b) 11 # c) 1b 485. at low ambient temperatures, an LCD screen a) loses contrast # b) is slower to update as data changes c) viewing angle becomes larger 486. Colour CRT shadowmask screen resolution is # a) 84 triads b) 400 lines per square inch c) 600 lines per scan 487. A multiplexer in test equipment could be used for # a) analogue to digital converter b) frequency divider c) digital to analogue converter

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 488. Where does the clock signal in a microiprocessor come from? a) ALU # b) Control unit c) Memory 489. Where is the operating program for the CPU stored? a) ALU b)Control unit # c) Memory unit 490. An LCD display # a) has three colours only b) has infinite colours c) is monochrome 491. in ARINC 629 aperiodic mode, LRUs transmit in order of a) power up # b) shortest terminal gap to longest terminal gap c) longest terminal gap to shortest terminal gap 492. ARINC 629, aperiodic mode is used a) for normal operation b) for landing and approach operation # c) for database loads 493. What is the device used to convert Binary Coded Decimal into separate supplies for a seven segment digital display? a) Multiplexer b) Demultiplexer # c) Decoder 494. How is ARINC 429 bi-directional data transfer achieved? a) Via a twisted pair of shielded cables # b) Using two data buses c) Via a current mode coupler 495. A basic computer would consist of a) register section, ALU and timing and control section # b) memory, input/output ports and CPU c) RAM/ROM and input/output ports 496. A B S 000 011 101 110 #

This is the truth table for a

a) E-OR b) NOT

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions c) NAND 497. Where is the rising runway? # a) EADI b) EFIS c) CRTs in the passenger cabin 498. What is ILS marker frequency? # a) 75 Mhz b) 100 Mhz c) 125 Mhz 499. On an external power socket the two short pins are a) for the AC interlock circuit # b) to prevent arcing when inserting and extracting the socket c) used to act as a guide 500. Flat plate antenna is # a) series of waveguides with slots b) a parabolic antenna c) used to transmit RF signals only 501. Relationship of CMCs to BITE systems is best described as a) CMCS replaced but is not related to the older BITE system. # b) CMCS monitors the individual BITE systems and presents data. c) CMCS modifies and upgrades BITE systems 502. Operation of a frequency counter is such that # a) it changes the incoming waveform to a standard square wave. b) It detects incidences of peak value c) it compares the incoming waveform with standard sine waves 503. As far as a software product is concerned # a) the 'Verification' phase includes performance testing a programmed EPROM b) the 'Validation' phase is done to the software rather than to the component. c) the 'Software Release' phase is the same as the 'Finished Product' phase 504. A segmented configuration for the display of alphanumeric date requires a) at least 13 segments for all upper and lower case letters b) the starburst display for numbers and lower case letters only. # c) 16 segments to display the full range of capital letters and numerals 505. for braided cables, the amount of braiding a) is a trade-off design feature b) must conform to the requirement for the shielding to cover at least 50% of the surface of the cable

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions # c) keeps radiated power inside the emitting assembly or away from the susceptible circuit 506. Electronic CRT beam display is used typically in a) IRU control display units. b) distance measuring indicators; digital counters # c) weather radar indicators 507. What is the quickest method of analogue to digital conversion? a) Voltage to frequency # b) Flash converter c) Single ramp method 508. in a colour cathode ray tube, how is the phosphor arranged in the tube? a) A red layer on the front with two green layers behind it b) Layers of red, blue and green # c) A single phosphor layer containing red, green and blue 509. An LCD which is back lit is a) monochrome b) three colours # c) multicoloured 510. An 8 data input multiplexer has how many Data select lines # a) 3 b) 2 c) 8 511. An electronic flight instrument display consists of; a) ADC, Altimeter, VSI and ASI # b) Mode control panel, Raster and Stroke generator display, microprocessor and Data inputs c) ADI, HSI and Symbol generator 512. An octal format hexadecimal number 3F written as binary would be a) 101 011 b) 110 111 # c) 111 111 513. What is a passive device? a) Matrix LCD # b) Capacitor c) LED 514. A priority encoder a) Outputs the selected input # b) Outputs the highest input c) Outputs the lowest input 515. The data format use to transmit signal to flight data recorder

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a) Manchester 2 bi-phase 12 bit b) Harvard bi-phase 12 bit c) Bi-Polar RZ 12 bit

516. The output voltage of arinc 429 signal is a) +5v b) -5v # c) +10v to -10v 517. How many bytes can be carried in a 32bit word # a) 4 bytes b) 2 bytes c) 8 bytes 518. An Arinc 629 label word is # a) 12 bits b) 8 bits c) 10 bits 519. Which of the following ESDS devices can withstand higher static electricity voltage? a) ECL b) MOSFET # c) SCR 520. An IRU interface test is carried out # a) only on the ground b) in the air c) on the ground or in the air 521. For a computer to start up the basic instruction is from the a) ALU b) RAM # c) ROM 522. What is a passive device? a) Matrix LCD b) LED # c) Capacitor 523. A backlighted LCD a) has infinite colours b) is monochrome # c) has only 3 colours 524. An example of a small size integrated circuit would be a) DIP switch b) ALU # c) Control Processor Unit

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 525. The smallest operation possible in a computer is the # a) timing cycle b) processor sub-cycle c) processor cycle 526. A common used material in computer manufacturing is a) ferrite material b) permeamag material # c) ferromagnetic material 527. FMS system gives warning indications for # a) cruise b) take off and landings only c) any flight phase 528. An aircraft on an ILS approach is below the glideslope centre line, the glideslope pointer is # a) above the centre line b) below the centre line c) level with the datum 529. A dot matrix/LED construction is # a) 4x7 or a 9x5 rolling end display b) 4x7 or a 5x7 rolling end display c) 5x9 or a 4x7 rolling end display 530. FMS CDU warnings are a) OFST and Fail b) fail and MSG # c) MSG, fail and OFST 531. A current mode coupler contains E core assembly. The purpose of the E core is # a) couple the signal to the data bus b)provide effective screening of the signal through the current mode coupler c) enable easy access for monitoring purposes 532. Testing of CADC can be carried out a) in the air # b) ground only c) air and ground 533. EHSI information displayed, is invalid in the pre-set heading mode when a) flags out of view b) flag green # c) flag in view 534. CMC (central maintenance computer) works to # a) perform in-flight bite and ground tests of aircraft systems, i.e.

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions BITE b) give red warnings and amber cautions to display in accordance with system status c) perform in-flight bite only 535. The TX/RX of Arinc 629 is a) encoder/decoder # b) multiplex/de-multiplex c) switching 536. Terminal gap in ARINC 629 is a) always the same period b) flexible # c) can be changed by adjusting the rx/tx software 537. DRAM # a) requires a refreshing charge b) memory is stored when power supply is removed c) it does not require a refreshing charge 538. What is f86 hex when converted to binary? a) 1000010000110 b) 100000000000 # c) 111110000110 539. BITE test carried out on input sensors and actuators performs a) a test of the LRU # b) a performance test of the system c) validation of the information of the LRU 540. A continuous balance ADC uses # a) a closed loop system to compare the analogue input to give the required digital output b) a closed loop system to check the analogue input with the input sample c) successive approximation logic circuit to control the output 541. A BITE check for automatic performance and fault monitoring is carried out when? # a) Power-up self test b) For in-flight monitoring c) To check the performance of the LRU 542. A clock pulse in processor equipment a) is used for the maintenance tests b) is to give the correct timing when calculations are made # c) is to synchronise everything 543. The EFIS system consists of # a) EADI, EHSI, Symbol generators

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions b) Mode control Panel, RDMI, EHSI c) EHSI, Mode control panel, EADI 544. in a computer, the address 3B8 is a) decimal b) octal # c) hexadecimal 545. in a optical fibre, the angle of acceptance is a) equal to the cone of acceptance # b) 1/2 the cone of acceptance c) 1/2 the signal wavelength 546. The signal sent between a MUX/DEMUX is controlled by: a) the ALU # b) control unit c) clock 547. in a computer, the code that fetches correct data and feeds it to the ALU is called a) the computer program # b) the instruction set c) ARINC 548. What is this?

#

a) Multiplexor b) Shift register c) Counter

549. Bubble memory stores data on # a) ferrite disk b) ferrite core c) magnetic tape Page 61

Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 550. Ferrite medium is used because # a) data is stored after the power is removed b) it has low eddy current losses c) it is light 551. A dynamic EPROM a) requires constant refreshing # b) is non-volatile memory c) is erased after reading 552. A computer requires to operate # a) data bus, control bus, address bus b) data bus, control bus c) address bus, data bus 553. A computer processor has within it # a) ALU, control section, register b) register, buffer, data bus c) ALU, register, memory 554. when using a TDR (time delay reflectometer) the loss value of the cable is: a) set on the TDR # b) shown by the curve c) allowed for in the calculation 555. Common aircraft fibre optics uses a) modulating intensity on direct read # b) modulating frequency on direct read c) modulating intensity on indirect read 556. What manoeuvre does TCAS II advise the pilot to make a) TA # b) RA c) either RA or TA 557. What are the shapes of traffic shown on a TCAS display? # a) White diamonds, red squares and amber circles b) White squares, red diamonds and amber circles c) White circles, red diamonds and amber squares 558. What is a Grays converter? a) Digital to Analogue # b) Analogue to Digital c) Analogue to Analogue 559. Data memory is usually stored in a) RAM # b) ROM

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions c) EEPROM 560. Tristate devices are found # a) on input circuits b) on output circuits c) on both input and output circuits 561. AWN 45 requires that a) The aircraft operator be responsible for software assessment # b) The aircraft constructors be responsible for software assessment c) The CAA be responsible for software assessment 562. What is the main cause of attenuation in fibre optics? a) Refractive index # b) Poor termination c) Bends in the cable 563. What are the advantages of an LCD display over an LED? a) It is brighter # b) It uses less current c) There are no advantages 564. If a dislay shows a red cross only, it is due to a) CRT failure # b) Symbol Generator failure c) Altimeter failure 565. What is the advantage of a laser diode over an LED? a) Greater bandwidth # b) Narrower bandwidth c) There are no advantages 566. How does ARINC 629 bus transmit and receive information? a) Optical coupling b) Sockets and pins # c) Inductive coupling 567. What is ARINC 561 used for? a) To specify Flight Data Recorder data bus # b) To specify Radio Comms data bus c) To specify LRU pin-outs 568. Sample and hold is a technique used in a) D to A convertion # b) A to D convertion c) Moving coil instruments 569. ACARS is an acronym for a) Analogue Communications Airborne Radio System b) Airborne Communications Addressing and Reporting System

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c) ARINC Communications Addressing and Reporting System

570. What are the colours of traffic shown on a TCAS display? # a) White diamonds, red squares and amber circles b) White squares, red diamonds and amber circles c) White circles, red diamonds and amber squares 571. Level 1 software failure # a) is defined as critical and can lead to loss of aircraft b) is defined as essential and will reduce safety margins c) is defined as essential and may have a minor effect 572. A wrist band must be worn when working with ESDS devices a) to prevent the operator from getting an electric shock b) to dissipate static charge on the device # c) to dissipate and prevent static build-up on the operator 573. A humid atmosphere a) eliminates static charge # b) reduces static charge c) has no effect on the level of charge 574. Control of aircraft software updates # a) is the responsibility of the certifying engineer b) is the manufacturer responsibility c) is identified by LRU pin-out changes 575. The arithmetic logic unit (ALU) in a central processor unit (CPU) carries out # a) addition, subtraction, multiplication and division b) timing and synchronisation c) computations as instructed 576. A seven segment display is used to a) display octal and binary numbers only b) display octal and decimal numbers only # c) display alpha-numeric characters 577. What sort of gate requires two negative input voltages to operate? a) NOT b) XOR # c) NAND 578. A high level language statement is usually equivalent to several statements in a) assembly # b) basic c) pascal 579. The CPU requires a clock to determine

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a) the speed of operation b) the date and time c) the number of bits on the highway

580. An ALU performs the following a) Arithmetic, Logic, Branch and Move Operations b) Arithmetic, Logic, Branch and Find Operations # c) Input/Output operations, Arithmetic, Logic Functions 581. HIRF is acronym for # a) High Intensity Radiated Field b) Heavily Ionised Radio Frequencies c) High Intensity Radio Frequencies 582. An asynchronous system a) uses a clock pulse after a settling time to input data # b) provides data real-time without the need for a clock pulse c) both a and b depending on the system 583. What is the purpose of the parity bit on an ARINC 429 bus? a) To indicate if the data is analogue b) To indicate that the data is digital # c) To indicate to the receiver that the data is valid 584. An analogue to digital converter (ADC) requires the following: a) a reference voltage, an input gate, an internal counter b) a reference voltage, an input gate, an internal counter, a comparitor # c) a reference voltage, an input gate, a comparitor 585. When does the flight data recorder start recording? # a) When the first engine starts b) Parking brake released c) Undercarriage up 586. ILS indications on PFD/ND are shown in a) cyan # b) magenta c) green 587. The four distinct sections of a digital system are: sense, decide a) divide and store b) divide and ship # c) act and store 588. Brake temperature displayed on a flight deck CRT has a) same colour throughout # b) different colour for different temperatures c) a master warning light 589. When does the lateral deviation scale flash?

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#

a) When the localiser rx is faulty b) When the aircraft is out of range c) When the deviation is excessive

590. What is Throughput rate for the A/D converter? # a) Number of complete digital words encoded in a specified unit of time. b) Speed of variable resistor which senses the analogue signal c) None of the above 591. What is the Resolution of A/D and D/A converters? a) Resolution of the Instrument which displays the values b) Rate at which data is converted # c) Number of discrete values that can be represented by the digital word 592. ARINC 429 is a) Single Source Single Sink system # b) Single Source Multiple Sink System c) Multiple Source Multiple Sink system 593. What is the purpose of intermediate production breaks in ARINC 429 or 629 Data cables? # a) To allow maintenance personnel to divide the right and left system buses into two parts for easy removal and installation b) To allow connection of new cables to the existing ones in case of a modification c) Cables are only manufactured 40 feet long Page 70 – Mod 5 594. How are Alphanumeric Displays produced on a CRT a) Raster scanning b) by the use of X & Y EM Coils # c) By Stroke pulse 595. In Positive Logic representation # a) State 1 is more positive than state 0 b) state 0 is more positive than state 1 c) both states have same positive voltages but stage 1 has more current 596. When performing test on Electronic Displays using the Built In Test system a) CRT continues to display current data while the SGs and Display are internally tested # b) SG injects a test signal into the display system and the word TEST appears on the screen c) Displays cannot be tested it is only SG which are tested by BITE 597. Strapdown Inertial Navigation system requires # a) Three accelerometers and three gyros b) Two Accelerometers and Three Gyros

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions c) only Ring Laser Gyros. By having the RLG there is no need of accelerometers 598. Heading reference required to establish initial heading during alignment sequence comes from a) Magnetic compass installed on the airplane b) FMS which gathers data from other Radio devices # c) Earths Rotation 599. What is primary mode of navigation on a Modern Aeroplane? a) Inch precise GPS b) Both GPS and IRS # c) Only IRS 600. HF aerials are protected against lightning strike by # a) spark gap b) bus terminal c) current mode coupler 601. Where is the parity bit installed in a data word? a) Front b) Middle # c) End MSB 602. In a flight director, how are small deviations corrected? # a) Instrument feedback b) Pilot input c) Instrument is calibrated at fitment to remove any possible error 603. Switching within logic gates is normally achieved with the use of a) relays # b) diodes c) BTB's 604. RZ bi-polar modulation consists of bits which are one of ------------ states? a) Two # b) Three c) Eight 605. Which one uses bistable switches or flip-flops? a) RAM # b) SRAM c) DRAM 606. A weather radar image can be displayed on the ND on all modes except a) nav rose b) arc # c) plan 607. In a typical commercial aircraft Head Up Guidance System

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions a) all instrument information is displayed on the windshield # b) the type of information shown on the attitude director indicator is displayed on a transparent plate c) only emergency indications or warnings are displayed to the pilot 608. In the ARINC 429 digital information transfer system, data may travel in: # a) one direction only b) both directions on the same bus simultaneously c) both directions on the same bus sequentially by time multiplexing 609. Digital signals can be represented a) only as a binary value # b) by a series of integers c) by real numbers 610. A modern Electronic Horizontal Situation Indicator will display the following: a) Ground speed, Magnetic Heading, Way points and Localiser # b) Waypoints, ILS Steering Information, Distance to go and Magnetic Heading c) ILS Steering Information, Flight director information and Glide Slope Deviation 611. An ARINC 629 data word a) includes an 8 bit label and a 16 bit data field b) comprises up to 256 data bits # c) has only 20 bits 612. Electrostatic discharge occurs when # a) materials of different potential are brought in close proximity to each other b) materials are rubbed together or pulled apart c) the ground lead on a wrist strap touches the skin 613. A type A fibre optic connector a) is used when regular disconnection and re-connection of a cable is required # b) would be used for connections not regularly disconnected c) produces a larger light loss that a type B connector 614. A full adder has a) two inputs and one output # b) three inputs and two outputs c) three inputs and one output 615. The truth table of A =0011 B=0101 and X =0110 indicates that the logic device is a) an AND gate b) a NOR gate

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c) an EXCLUSIVE OR gate

616. In an ARINC 429 digital word bit number 32 is used for # a) checking parity b) identifying word type c) terminating the data field 617. Transistors are used in Digital to Analogue converter to a) switch the input to "ON" # b) switch the output to "OFF" c) connecting the output to earth 618. For a 3 dimensional fix in a Global Positioning System # a) Minimum of 4 satellites must be in view b) Minimum of 3 satellites must be in view c) Minimum of 2 satellites must be in view and altitude used to simulate a 3rd satellite 619. Cockpit panels have a matt colour finish. The purpose is a) so that dust and dirt are less evident on panels # b) so that the amount of glare is reduced to minimum c) so that pilots feel more comfortable during daytime 620. When testing EGT probe # a) it must be soaked and ambient temperature allowance taken into consideration b) if its not soaked, a minimum temperature of 20 degrees C taken as OAT c) not necessarily soaked but ambient temperature must be taken into consideration 621. What is the hexadecimal number AE5 in octal form # a) 5345 b) 5340 c) 5445 622. The firmware used to convert High level instructions into Binary machine codes in a computer is called a) Assembler b) Converter # c) Compiler 623. In an aircraft equipped with TCAS II and EFIS a) RA pitch command is shown on the EHSI and TA/RA traffic on the EADI # b) RA pitch command is shown on the EADI and TA/RA traffic on the EHSI c) RA pitch command is shown on the VSI and TA/RA traffic on the EHSI

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 624. The BITE indicator on a DFDR shows Yellow color. This indicates a) power is ON and DFDR is recording data # b) power is OFF or DFDR is at Fault c) power is ON but DFDR is not recording data 625. A Digital to Analogue Converter has a resolution of 0.3 Volts. What will be the analogue output when the digital input is 10110 # a) 6.6 Volts dc b) -6.6 Volts dc c) 6.6 Volts rms 626. In a Master Slave, negative edge triggered JK flip flop, both inputs are connected to logic 1. The output a) will change state when the leading edge of the clock pulse is applied b) does not change state when a clock pulse is applied # c) will change state when the trailing edge of the clock pulse is applied 627. The Shorter lead near the Flat portion of an LED is the a) Anode b) Gate # c) Cathode 628. What connects an LRU to the Bus Coupler in an ARINC 629 Data Bus? a) Patch Cord # b) Stub Cable c) Interconnect Cable 629. What do bits 1 to 8 represent in ARINC 429? # a) Source of the word b) measured parameter c) Destination 630. Before removing an assembly from an aircraft, with regards to HIRF, you must first ensure that there is minimum current flow between a) you and the aircraft # b) you and the assembly c) the assembly and the aircraft 631. A complete EFIS installation in an aircraft is made up of # a) left (captain) and right (co-pilot) b) right (captain) and left (co-pilot) c) either of the above 632. Requirements for configuration management of software can be found in a) ATA Chap 46, Information Systems b) JAR Ops (M) # c) AWN 43 633. Where would you find the rules regarding upgrade of software?

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a) The aircraft manufacturer b) AWN 43 c) JAR OPS

634. In a typical 'Glass Cockpit' EICAS provides the following: a) engine warnings only # b) engine parameters and system warnings only c) engine parameters and engine warnings only 635. On a modern "glass cockpit" aircraft engine information will be displayed on a) ECAM b) FMS c) EFIS 636. When removing a PC card from an ESDS assembly ensure a low current path between a) you and the assembly # b) you and the aircraft c) aircraft and ground 637. What does EFIS mean? a) Electronic Fire Indication Signal # b) Electronic Flight Instrument System c) Electronic Flight Information System 638. What does EICAS mean? # a) Engine indicating and Crew ale b) Electronic indic tor c) Electronic indic tor and crew 639. What does ECAM mean? a) Engine Centralised Aircraft Mo # b) Electronic Centralised Aircraf c) Engine Centralised Aircraft Ma 640. What is the minimum requirement for CVR to operate? a) BEFORE engine start # b) BEFORE take- off c) at any time the manufacturer decides 641. ECAM system was adopted for a) Boeing 757 and 767 aircraft # b) Airbus A310 c) both Boeing and Airbus aircraft 642. HIRF stands for # a) High Intensity Radia b) High Intensity Radio c) High Intensity Radiated Force

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Module 5 – Digital Techniques/Electronic Instrument Systems Sample Questions 643. What input is required to activate the relay?

#

a) A=0 B=1 b) A=1 B=0 c) A=1 B=1

644. A computer is acting in real time when a) the time to access memory is equal to the data speed in # b) the output is equal to the input of data c) the CPU requires a clock pulse 645. A modern electromagnetic Flight Data Recorder, for recording data, could use: a) a floppy disk # b) a plastic tape coated in ferrite c) a copper oxide string 646. An optical fibre is constructed from a) a plastic core with a high refractive index cladding b) a silica glass core with a high refractive index cladding # c) a silica glass core with a low refractive index cladding 647. Command bars on a modern EFIS represent a) actual flight path in relation to required flight path b) actual flight path in relation to the horizon # c) required flight path in relation to actual flight path 648. A number represented as a physical quantity, e.g. voltage or speed of rotation is # a) analogue b) digital c) maximum value 649. A NAND gate has inputs A and B and output C. If the output (c) was zero, what are the inputs? a) A=0 B=0 b) A=1 B=0 # c) A=1 B=1 650. Hexadecimal 5C is what in binary?

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#

a) 1110100 b) 1011111 c) 1011100

651. What is the minimum requirement for a CVR to start recording? a) On commencement of flight # b) When aircraft is capable of moving under its own power c) When parking brake is released 652. Binary 11001101 converted to octal is a) 205 # b) 315 c) 12E 653. What is the binary notation for 29? # a) 0001 1101 b) 0001 0110 c) 0010 1001 654. As a minimum requirement when must a cockpit voice recorder start recording? a) Once airborne after take off # b) Once aircraft is ready to move under its own power c) Before engine start

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Module 5

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