Propulsion Engine Indication Systems.pdf

Fundamentals eJAMF

Module 14.02 Propulsion / Engine Indication Systems AT ATA 77, 79

EASA Part-66

B2 EJAMF M14.02 B2 E

Issue: 26.07.2012 Author: SwD For Training Purposes Only  LTT 2006

Training Manual

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ENGINE INDICATION SYSTEMS



ENGINE INDICATION SYSTEMS INTRODUCTION & TREND MONITORING

INTRODUCTION & TREND MONITORING ENGINE INDICATION SYSTEMS Engine indications are used to monitor the parameters of the engine and its systems. The engine indications can be divided into 3 groups. − First, there are the performance indications, that are also named primary indications. − Then there are the system indications, that are also called secondary indications. − The third group of indications is used for engine trend monitoring and usually not shown in the cockpit. The performance indications are used to monitor the performance and the limits of the engine, and to set the thrust for the different flight phases. The system indications are used to monitor the operation of engine systems such as the oil or fuel system. They are also used to detect malfunctions quickly. Engine trend monitoring is done on the ground to detect engine problems at an early stage. It uses engine parameters that are automatically recorded by the aircraft condition monitoring system (ACMS).

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Figu Figure re 1

Engi Engine ne Ind Indic icat atio ion n Syst System em



ENGINE INDICATION SYSTEMS INTRODUCTION & TREND MONITORING Engine indication systems cont. You can can find engine indications, such as the ones shown shown on this ECAM display system, which have a combination of gauge type analog displays and digital readouts. There are also analog indications with moving vertical bars, such as the ones shown on this EICAS display.

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Figu Figure re 2

Engi Engine ne Per Perfo form rman ance ce Indi Indica cati tion on


ENGINE INDICATION SYSTEMS INTRODUCTION & TREND MONITORING ENGINE PERFORMANCE INDICATIONS The indication which is always located at the top is used to monitor and set the engine thrust. Because it is not possible to measure the thrust directly, there are 2 different indications which give an equivalent value. This is either  the rotational speed of the fan, called N1, or  the engine pressure ratio. The other performance indications are the engine rotor speed indications for each rotor system. This means that in addition to N1 there is N2 and, if available, also N3. There is also the exhaust gas temperature indication (EGT) and the fuel flow indication. Data for the indications is measured by specific sensors or probes. The data is usually electrically transmitted to the indicators. Sensors fitted to engines with a FADEC system will first transmit the data to the FADEC system computer. The computer then sends the data to the indicators or display system and also uses it to control the engine.

ENGINE SYSTEM INDICATIONS


We use the secondary engine indications to monitor the correct operation of engine systems. These are also called engine system indications. The indications for the oil system monitor the oil quantity, the oil pressure, and the oil temperature. The engine vibration indication shows you any imbalance that occurs in the rotating parts of the engine. For example an imbalance can be generated by damage to blades or bearings. The nacelle temperature increases for example when there is a leakage of hot air in the engine nacelle. The indications on the EICAS generally give the same information as the indications on the ECAM, although they are shown in a different way.

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Figu Figure re 3

Engi Engine ne Per Perfo form rman ance ce Indi Indica cati tion on 2



ENGINE INDICATION SYSTEMS INTRODUCTION & TREND MONITORING Engine system indications cont. There are also warnings and cautions displayed on the ECAM / EICAS page  when an indication exceeds a limit, or  when, as shown here, the system detects a low oil pressure, or  when a filter gets clogged as indicated here, or  when an unlocked thrust reverser is detected.

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Figu Figure re 4

Engi Engine ne Syst System em Indi Indica cati tion ons s



ENGINE INDICATION SYSTEMS INTRODUCTION & TREND MONITORING ENGINE TREND MONITORING Modern engines are very reliable and economic, but the performance of the engine modules decrease during their lifetime. To prevent larger performance reductions or even engine problems during flight, you need a monitoring tool that alerts us to a problem at an early stage. This tool is called engine trend monitoring. The engine trend monitoring is done in the workshop by analyzing engine data that is periodically recorded during flight by the aircraft condition monitoring system. The ACMS provides this data on a print-out from the cockpit printer, and it can also usually transmit the data via the ACARS datalink to the ground. The transmitted engine data is analyzed by a computer system in order to find any parameters that indicate a trend towards a limit. 3 different analyses are usually done:  the thermodynamic analysis,  the mechanic−dynamic analysis, and  the oil consumption analysis. The thermodynamic analysis checks the pressures and temperatures along the gas flow path. It also monitors the feedback signals from the VSV and VBV, the active clearance control, and the fuel flow. The data gives exact information about the condition of the engine components involved in the thermodynamic process. The mechanic-dynamic analysis mainly checks for failures in the rotor system, for example imbalances and bearing failures. To do this it checks engine vibration and rotor speed signals. The oil consumption analysis generates an alert when the oil consumption exceeds a certain level.

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Figu Figure re 5

Engi Engine ne Trend rend Mon Monit itor orin ing g



ENGINE INDICATION SYSTEMS ROTOR SPEED INDICATION

ROTOR SPEED INDICATION INTRODUCTION In all engines there is a rotor speed indication for each individual rotor system. There is a N1 indication for the low pressure rotor and a N2 for the high pressure rotor. There is also a N3 indication if the engine has 3 rotors. The engine rotor speed indications are always always expressed as a percentage of a 100% design speed. Now read the N1 value for engine number 2 in the example. Each rotor speed indication has 3 main parts:  the sensor  the data transmission  and the indication.

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Figure 6

Introduction



ENGINE INDICATION SYSTEMS ROTOR SPEED INDICATION TACHOMETER GENERATOR There are 2 different types of sensor, which can measure rotor speed on engines. One is the variable reluctance type sensor. The other is the tachometer generator type, which is usually located on the gearbox. The tachometer generator has a permanent magnet that is driven by the gearbox with a speed that is proportional to the N2 rotor speed. The rotating magnetic field generates a 3 −phase AC voltage with a frequency that is proportional to the input speed. The frequency is converted back to the speed signal in either a computer or indicator.

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Figu Figure re 7

Tachom chomet eter er Gene Genera rato torr



ENGINE INDICATION SYSTEMS ROTOR SPEED INDICATION Tachometer generator cont. In older generation aircraft there are rotor speed indicators, which are driven directly by the voltage from the tachometer generator. The indicator has a synchronous AC motor that generates a speed proportional to the input frequency, which is the same as the speed of the drive shaft on the tachometer generator. An eddy current clutch transfers the speed into a proportional proportional torque, which moves the gauge pointer to the correct indication.

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Figure ure 8

Direct In Indic dication tion



ENGINE INDICATION SYSTEMS ROTOR SPEED INDICATION Tachometer generator cont. In modern aircraft systems the tachometer generator sends the 3 −phase AC voltage to the FADEC computer, where it is used to calculate the speed signal. The tachometer generator also supplies electrical power to the computer and is therefore also called dedicated generator or control alternator.

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Figure ure 9

FADEC Gener nerator tor



ENGINE INDICATION SYSTEMS ROTOR SPEED INDICATION VARIABLE VA RIABLE RELUCTANCE RELUCTANCE SPEED SENSOR SENSOR Now let us have a look at the variable reluctance speed sensor, which is normally used to measure the N1 rotor speed. The variable reluctance sensor is positioned directly in line with the phonic wheel on the compressor shaft. As you can see phonic wheels have different different shapes, but this is not important. The important thing is that the rotating phonic wheel alternates metal and air at the tip of the sensor to change the sensor’s magnetic field. Because the sensor must be located near the compressor shaft, it often needs a long support tube to make replacement of the sensor possible. You must must be very careful during replacement not to bend or damage damage the probe.

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Figu Figure re 10

Sens Sensor or and and Pho Phoni nic c Whe Wheel el



ENGINE INDICATION SYSTEMS ROTOR SPEED INDICATION Variable reluctance speed sensor cont. There are similar sensor types located near the fan blades on some engines. The fan blades are used instead of a phonic wheel to change the magnetic field of the sensor. You can can find also a variable reluctance type sensor sensor on the gearbox which measures the N2 rotor speed. In this installation a gear in the gear box has the function of the phonic wheel. In all applications a computer is used to calculate the rotational speed from the sensor pulses.

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Figur Figure e 11

Varia ariabl ble e Rel Reluc ucta tanc nce e Speed Speed Sens Sensor or



ENGINE INDICATION SYSTEMS ROTOR SPEED INDICATION SPEED INDICATIONS There are 3 different types of rotor speed indication:  a display with a clock type scale,  a display with a moving vertical bar, and  the classical electromechanical indicator. All 3 indications show the actual N1 value with an analog and a digital digital indication. There is always a speed limit indication, which is usually a red line. This is the maximum permitted rotor speed.

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Fig Figure 12

Spee peed Ind Indications



ENGINE INDICATION SYSTEMS ROTOR SPEED INDICATION Speed indications cont. When actual N1 exceeds the red limit it can damage the engine. To make this dangerous situation clear to the pilot, the indications on the displays change to red accompanied by warnings from the central warning system. The maximum exceedance value is recorded and in modern aircraft it also initiates an exceedance report from the engine trend monitoring. This is used for planning the necessary maintenance actions.

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Figu Figure re 13

Exce Exceed edan ance ce Recor ecordi ding ng



ENGINE INDICATION SYSTEMS ROTOR SPEED INDICATION LIMIT INDICATIONS When N1 decreases below the red limit, a red exceedance pointer shows the recorded maximum exceedance value or you just get a red box around the digital readout to show that an exceedance occurred. You can read read the value with the onboard maintenance system. system. You can can reset the exceedance value when you finish the the necessary maintenance actions. You can can reset the exceedance indication by pressing the corresponding push button in the cockpit. In modern aircraft this is done automatically with the next engine start.

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Figu Figure re 14

Exc Exceeda eedanc nce e Poin Pointe terr



ENGINE INDICATION SYSTEMS ROTOR SPEED INDICATION Limit indications cont. When the N1 indication is used to set engine power, then an additional indication is needed to show the pilot the N1 value for the required thrust. This value is called  N1 limit, or  N1 command, or  reference N1. The N1 limit or N1 command shows the N1 that is required for a specific flight phase, such as take-off or climb. The value is calculated by the flight management or autothrottle system. There is always an analog indication on the scale and an additional digital readout. You can can also set this value manually with the knob on on the lower indicator. For the displays you set the value via the flight management system. On some displays you also can find an amber line that shows the N1 for the maximum available thrust, and a blue circle or white line that shows the N1 for the actual throttle position.

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Figure 15

N1 Command



ENGINE INDICATION SYSTEM EPR INDICATION

EPR INDICATION INTRODUCTION You only only find an EPR indication for some engine types. It is always located located at the top of the engine indications, because it is used to set the engine power. The EPR corresponds to the engine thrust, because it is the ratio of the total pressure at the turbine outlet to the total pressure at the fan inlet. Other engine types do not need an EPR indication, because the power is set with the N1 indication. Each EPR indication system has 3 main parts:  2 pressure pickups that are connected by tubes with a computer,  a computer, which is either a separate EPR transmitter or part of the FADEC computer, and  the indicator, which is located in the cockpit.

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Figu Figure re 16

EPR EPR Indi Indica cati tion on Sys Syste tem m Comp Compon onen ents ts



ENGINE INDICATION SYSTEM EPR INDICATION PRESSURE SENSORS To calculate and indicate the EPR you must measure 2 pressures. The pressure is given the name of the station that detects it, for example the P2 and the P5 pressure. P2 is the total air pressure at the fan inlet. It is measured by a pressure probe, which is located in the fan airstream. Like other air data probes it is electrically heated to prevent icing. P5 is the total gas pressure at the turbine exit. This pressure is also sensed by probes or, like in this example, with small holes in 3 of the turbine nozzle guide vanes. The individual pressures are collected by pickups in the turbine case and guided by tubes to a common pressure manifold. This gives an average P5 pressure value. The 2 pressure values are passed to the computer for it to calculate the pressure ratio. Shown here is an EPR transmitter, which is an earlier type of computer. Before the calculation can occur, the computer must change the pressure into a proportional electrical signal. The EPR transmitter uses electromechanical pressure transducers with, for example, bourdon tubes. The photo shows an example of bourdon tubes.

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Figu Figure re 17

Sens Sensor ors s and and Tra Trans nsmi mitt tter er



ENGINE INDICATION SYSTEM EPR INDICATION Pressure sensors cont. On modern engines the EPR calculation is done in the FADEC computer. It uses electronic pressure transducers like in the air data system. These transducers are much smaller, more reliable and more exact than the electromechanical transducers.

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Figure ure 18

Sensors an and FA FADEC



ENGINE INDICATION SYSTEM EPR INDICATION EPR INDICATION In this segment we will show you 2 different types of EPR indication. Firstly, the indication on a display unit which you find on modern aircraft, and secondly, secondly, the classical electromechanical indicator on older generation aircraft.

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Figure 19

EPR Indications



ENGINE INDICATION SYSTEM EPR INDICATION ADDITIONAL INDICA INDICATIONS TIONS You may have noticed that the actual EPR indication indication is shown by an analog and a digital value. The EPR command has the same function as the N1 command. This example shows the EPR required for a flexible take-off. On the classical indicator this value is called the EPR limit, which is also shown in both analog and digital format. You can can also set the value manually by pulling the the knob. On the display you can find 2 more indications. This is:  the amber line that shows the EPR for the maximum available thrust and  a blue circle that shows the EPR that corresponds to the actual throttle position.

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Figu Figure re 20

Addit dditio iona nall Indic ndica ation tions s



ENGINE INDICATION SYSTEMS EGT INDICATION

EGT INDICATION INTRODUCTION There must be an exhaust gas temperature indication for each engine. The indication is necessary to monitor the high temperatures in the engine exhaust in order to see when a limit is exceeded. The highest temperature is directly behind the combustion chamber where the hot gas hits the high pressure turbine. This temperature is called the turbine inlet temperature or TIT. TIT. Because this temperature can be higher than 1,400  C, it is not easy to measure the TIT. The exhaust gas temperature (EGT) is therefore measured at a colder location in the engine either between the high and low pressure turbine or directly behind the low pressure turbine. This is possible because the EGT has a direct relationship to the TIT. TIT. Because of the different measuring points you can find maximum EGT indications between 600 C and 900C.

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Figu Figure re 21

EGT EGT Ind Indic icat atiion Sys System tem



ENGINE INDICATION SYSTEMS EGT INDICATION EGT PROBES To measure and indicate the EGT you need:  temperature sensors,  a means of transmitting data, and  a method of indication. To measure high temperatures you need sensors of the thermocouple type. There are several thermocouples on the engine. In the example shown here there are 9. They are installed in the turbine case of the engine. All thermocouples are connected to each other other in order to generate a common temperature value. The thermocouples for the EGT are always connected in parallel in order to measure the average exhaust gas temperature. The parallelling is done in junction boxes. To To make probe replacement easier, on some engines the thermocouples are parallelled in groups in parallel junction boxes. All signals are then combined combined in the main junction box and transferred to the FADEC system. You may may recall that special wiring is needed from the probes probes to the cold junction. In our example the cold junction is located located in the FADEC system computer.

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Figu Figure re 22

EGT EGT Indi Indica cati tion on Comp Compon onen ents ts



ENGINE INDICATION SYSTEMS EGT INDICATION EGT INDICA INDICATION TION You are now going to look at 3 different types of EGT indication:  the display with a clock type scale,  a display with a moving vertical bar, and  the classical electromechanical indicator. All 3 indications show the actual exhaust exhaust gas temperature in degrees Celsius in both analog and digital. They also always show the temperature limit, usually as a red line. This is the maximum permissible EGT that should never be exceeded. When an EGT red limit exceedance occurs in modern systems, then you get information which is basically the same as you get when a rotor speed exceedance occurs. On each display there is also an amber line that shows the maximum EGT for the maximum continuous thrust setting. The EGT is only allowed to exceed the amber line value for a short time when the engines run at take-off or go around thrust.

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Fig Figure 23

EGT Indications



ENGINE INDICATION SYSTEMS FUEL FLOW INDICATION INDICATION

FUEL FLOW INDICATION SYSTEM ARCHITECTURE The fuel flow indicating system provides 2 different indications for the pilot:  The actual fuel flow to the engines, which is in kg or tons per hour, and  the fuel used since the engine was started. This is in kg or tons. The fuel flow indication allows you to monitor the performance and economic operation of the engines. The engines usually have the same power setting and therefore each flow indicator should also show identical fuel flow. The fuel used indication shows the mass of fuel which was burned since the last engine start on ground. This allows to compare the performance of the different engines. It also gives a redundant information for the actual fuel quantity. You can calculate calculate the actual fuel quantity by subtracting the amount amount of used fuel from the amount of fuel in the tanks at take-off. The fuel used indication is usually automatically reset to 0 when the engine master switch is switched to ON and the aircraft is on the ground. To generate the fuel flow and fuel used indications there needs to be a fuel flow transmitter on each engine and then a calculation has to be done. The calculation in modern systems is usually done by the FADEC system computer.

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Figu Figure re 24

Fuel Fuel Flow Flow Indi Indica cati tion on Syst System em



ENGINE INDICATION SYSTEMS FUEL FLOW INDICATION INDICATION FUEL FLOW TRANSMITTER INTRODUCTION The fuel flow transmitter measures the mass flow of fuel between the fuel control unit and the fuel nozzles. There are different types of fuel flow transmitter, but their operation is always based on a basic law of Physics: force is equal to mass times acceleration. All transmitter types measure the force, which is applied by the mass of fuel.

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Figu Figure re 25

Powe Powere red d Fuel Fuel Flow Flow Trans ransmi mitt tter er



ENGINE INDICATION SYSTEMS FUEL FLOW INDICATION INDICATION FUEL FLOW TRANSMITTER TYPES In the transmitter type shown here the fuel mass turns a turbine against a spring and the deflection angle is measured. To get the force you must accelerate the fuel. This is done here by an impeller that rotates continuously, driven by an electric motor. The mass of fuel is proportional to the turbine angle, because the acceleration of the fuel is constant. A position transducer, such as synchro synchro or RVDT, RVDT, measures the turbine angle and sends it to the indicator. The indicator shows the fuel flow directly and also calculates the fuel used value by an integration of the fuel flow rate.

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Figu Figure re 26

Powe Powere red d Fuel Fuel Flo Flow w Tra Trans nsmi mitt tter er 2



ENGINE INDICATION SYSTEMS FUEL FLOW INDICATION INDICATION Fuel flow transmitter types cont. Modern fuel flow transmitters do not need an electric motor with a power supply. They use the fuel itself to generate the acceleration. In this transmitter type the fuel flow turns a small turbine. The rotating turbine also drives a drum and an impeller, which is located inside the drum. Both are coupled by a spring. The fuel drives the turbine, drum, and impeller with a speed that is proportional to the volume of fuel. Behind the turbine the fuel passes through a fixed straightener that stops all possible fuel spin. The straightened fuel then passes through the rotating drum without affecting the rotation of the drum. Then the fuel hits the impeller blades. The force of the fuel delays the rotation of the impeller, until this braking force is compensated by the force of the spring. The angle between the rotating drum and the rotating impeller is proportional to the mass fuel flow. The transmitter measures this angle with 2 coils in combination with 4 permanent magnets. 2 magnets are located on the drum and 2 are located on the impeller. When a magnet passes the coil, it induces a voltage pulse in the coil. In our example this happens twice for each rotation. With no fuel flow the angle is zero and therefore the magnets on the drum and the impeller pass the coils at the same time. When there is fuel flow, the impeller magnet is delayed by an angle in proportion to the fuel mass. When this happens, the pulse from the impeller coil is also delayed. The FADEC system computer now calculates the time between the 2 pulses, which is proportional to the mass fuel flow. An integration of the fuel flow value gives the required required fuel used information.

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Figu Figure re 27

Fuel Fuel Flow Flow Indi Indic cati ation



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM

ENGINE OIL MONITORING SYSTEM OIL QUANTITY INDICATION The oil quantity transmitter in the tank sends the information via a computer, which performs the measurement, in this example called the engine interface unit (EIU), to the display units in the cockpit.

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Figu Figure re 28

Oil Oil Quant Quantit ity y Indic Indicat atin ing g Sche Schema mati tic c



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM Oil Quantity Indication cont. The oil quantity transmitter is normally installed at the top of the oil tank. This allows the transmitter to be changed without draining the tank. 2 types of transmitter are used  the capacitance type transmitter and  the reed switch type transmitter.

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Figur Figure e 29

Diff Differ eren entt Typ Types es of of Quan Quanti tity ty Tra Trans nsmi mitte tterr



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM Oil Quantity Indication cont. Here you see the capacitance type transmitter. The upper part has the electronic components for the capacitance measurement and an electrical connector. The lower part, which is immersed in the oil, has 2 concentric tubes. These are the 2 plates of the capacitor .

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Figu Figure re 30

Capa Capaci cita tanc nce e Typ Type e Tra Trans nsmi mitt tter er



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM Oil Quantity Indication cont. The reed type transmitter has a metal tube with a float inside and a multi switch assembly. The metal tube has holes to let the oil in from the tank so that the float can move up and down with the oil level in the tank. The float assembly has permanent magnets, which activate an internal switch assembly. The multi switch assembly has a ladder of reed switches connected by resistors. The magnet in the float always closes the switch nearest to it. When, for example, the oil tank is full, then the float is at the upper limit of its travel. The magnet in the float assembly causes the top switch in the ladder to close. In this situation the resistance in the electrical circuit is at its minimum, and this gives maximum output voltage from the transmitter. You have have seen that when the oil level falls, the float also falls. The switch nearest to the float closes and all other switches open. The electrical resistance in the circuit changes with the switch that is closed and this gives a corresponding output voltage from the transmitter.

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Figu Figure re 31

Reed Reed Swi Switc tch h Typ Type e Tra Trans nsmi mitt tter er



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM OIL PRESSURE INDICATION INDICATION The oil pressure transmitter is connected to the oil supply line and to the oil tank vent line. The transmitter senses the pressure difference between the total oil pressure in the oil supply line and the vent pressure in the oil tank. Oil pressure information is sent from the oil pressure transmitter to the engine interface unit, which performs the measurement and then to the display unit in the cockpit.

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Figu Figure re 32

Oil Oil Pres Pressu sure re Ind Indic icat atio ion n Syst System em Sche Schema mati tic c



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM OIL PRESSURE SENSOR There are two main types of oil pressure transmitter − the bourdon tube type and the strain gage type.

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Figu Figure re 33

Oil Oil Pre Press ssur ure e Sens Sensor ors s



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM LOW OIL PRESSURE SWITCH An additional pressure switch is used in the engine oil system to initiate a low oil pressure warning. The pressure switch is also connected to the oil supply line and the oil tank vent line. If the oil pressure decreases below the limit, the low oil pressure switch closes, a signal is sent to the flight warning computer, and a warning message appears on the display unit in the cockpit. Note also, that the engine low oil pressure warning is always accompanied by an acoustic warning in the cockpit.

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Figu Figure re 34

Low Low Oil Oil Pres Press sure ure Swi Switc tch h



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM Low Oil Pressure Switch cont. Here you can see the location of the oil pressure transmitter and the low oil pressure switch on an engine. In this example they are installed on the fan case in the ten o’clock position. You can can see where each is connected to the oil supply supply line and the oil tank vent pressure line.

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Figure Figure 35

Pressu Pressure re Trans Transmitt mitter er & Low Low Pressu Pressure re Switch Switch Locati Location on



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM OIL TEMPERATURE INDICATION The location of the oil temperature sensor in the lubrication system depends on the engine type. The sensor can be found in the scavenge system, where it senses the hot oil temperature upstream of the oil cooler, or it can be found in the pressure system, where it senses the temperature of the cooled oil. Oil temperature information is sent from the oil temperature sensor to a computer, which performs the measurement and then to the display unit in the cockpit. There are 2 main types of oil temperature sensor − the thermocouple and the thermistor.

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Figu Figure re 36

Oil Oil Tempe empera ratu ture re Indi Indica cati tion on



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM Oil Temperature Indication cont. There are 2 main types of oil temperature sensor − the thermocouple and the thermistor.

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Figu Figure re 37

Oil Oil Tem Tempe pera ratu ture re Sen Senso sorr Locat Locatio ion n



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM Oil Temperature Indication cont. There are 2 main types of oil temperature sensor − the thermocouple and the thermistor.

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Figu Figure re 38

Oil Oil Te Temper mpera ature ture Sen Senso sorr



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM OIL CONTAMINATION MONITORING As you already know, the engine engine oil carries particles from the bearings and and the gears to the filters in the lubrication system. You can monitor monitor the quantity, the size, and the type type of material of these particles to get some indication of the internal wear of lubricated engine parts. A process called Spectrometric Oil Analysis Program, or SOAP for short, is used to find out about internal wear of lubricated engine components. This SOAP analysis can find particles in the oil, which are so small that they can not be caught by the oil filters. These particles range in size from 0.001 mm to 0.02 mm. It is important to monitor the concentration of these particles in the oil to identify increased wear at an early stage. Many particles indicate increased wear and knowledge of the material helps to identify the engine part with increased wear. Oil samples for SOAP are taken from the oil tank at regular intervals and sent to the laboratory for analysis.

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Figu Figure re 39

Spec Spectro trome metr tric ic Oil Oil Anal Analys ysis is Prog Progra ram m



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM Oil Contamination Monitoring cont. The scavenge oil filter element catches larger particles which are of a size of more than 0.015 mm. These particles can be removed and sent for analysis. The problem with this is that the filter element is not changed very often and each filter inspection takes time. Magnetic chip detectors are an easier and less time consuming method to get information about the condition of the oil. Magnetic chip detectors catch metal particles which are attracted to the magnet. They can be easily removed and the condition can be checked. The magnetic chip detectors can be manually checked at fixed intervals or on some modern aircraft they can be electronically monitored and removed when necessary.

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Figu Figure re 40

Magn Magnet etic ic Chi Chip p Dete Detect ctor ors s



LUBRICATION LUBRICATION SYSTEM ENGINE OIL MONITORING SYSTEM Oil Contamination Monitoring cont. Here you see an electronically monitored chip detector, installed in the scavenge oil line. This chip detector has 2 magnets at its tip. The resistance between the 2 chip detector magnets is monitored by the electronic control unit. The resistance decreases when particles connect with the magnets. When the resistance between the magnets gets below the limit, the electronic control unit sends a maintenance message for the post flight report.

eJAMF Propulsion



eJAMF Propulsion


Figur Figure e 41

Elec Electro troni nic c Magn Magneti etic c Chip Chip Dete Detecto ctors rs

EJAMF M14.02 B2 E

TABLE OF CONTENTS

ENGINE INDICATION SYSTEMS . . . . . . . . . . . . .

1

INTRODUCTION & TREND MONITORING . . . . . . . . . . . . . . . . . . . . . . ENGINE INDICATION SYSTEMS . . . . . . . . . . . . . . . . . . . ENGINE PERFORMANCE INDICATIONS . . . . . . . . . . . . ENGINE SYSTEM INDICATIONS . . . . . . . . . . . . . . . . . . . ENGINE TREND MONITORING . . . . . . . . . . . . . . . . . . . .

2 2 6 6 10

ROTOR SPEED INDICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TACHOMETER GENERATOR . . . . . . . . . . . . . . . . . . . . . . VARIABLE RELUCTANCE SPEED SENSOR . . . . . . . . . SPEED INDICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LIMIT INDICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

12 12 14 20 24 28

EPR INDICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PRESSURE SENSORS . . . . . . . . . . . . . . . . . . . . . . . . . . . EPR INDICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ADDITIONAL INDICATIONS . . . . . . . . . . . . . . . . . . . . . . .

32 32 34 38 40

EGT INDICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EGT PROBES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EGT INDICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

42 42 44 46

FUEL FLOW INDICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SYSTEM ARCHITECTURE . . . . . . . . . . . . . . . . . . . . . . . . FUEL FLOW TRANSMITTER INTRODUCTION . . . . . . . FUEL FLOW TRANSMITTER TYPES . . . . . . . . . . . . . . .

48 48 50 52

ENGINE OIL MONITORING SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . OIL QUANTITY INDICATION . . . . . . . . . . . . . . . . . . . . . . . OIL PRESSURE INDICATION . . . . . . . . . . . . . . . . . . . . . . OIL PRESSURE SENSOR . . . . . . . . . . . . . . . . . . . . . . . . . LOW OIL PRESSURE SWITCH . . . . . . . . . . . . . . . . . . . . OIL TEMPERATURE INDICATION . . . . . . . . . . . . . . . . . . OIL CONTAMINATION MONITORING . . . . . . . . . . . . . . .

56 56 64 66 68 72 78

EJAMF M14.02 B2 E

TABLE OF CONTENTS

EJAMF M14.02 B2 E

TABLE OF FIGURES Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure

1 2 3 4 5 6 7 8 9 10 10 11 12 13 14 15 16 17 17 18 19 20 21 22 22 23 24 24 25 26 27 28 29 30 31 31 32 33 34 34 35

Engine Indication System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Engine Performance Indication . . . . . . . . . . . . . . . . . . . . . . . . . . Engine Performance Indication 2 . . . . . . . . . . . . . . . . . . . . . . . . Engine System Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Engine Trend Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tachometer Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Direct Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FADEC Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sensor and Phonic Wheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Variable Reluctance Speed Sensor . . . . . . . . . . . . . . . . . . . . . . Speed Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exceedance Recording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exceedance Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N1 Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EPR Indication System Components . . . . . . . . . . . . . . . . . . . . Sensors and Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sensors and FADEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EPR Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EGT Indication System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EGT Indication Components . . . . . . . . . . . . . . . . . . . . . . . . . . . EGT Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel Flow Indication System . . . . . . . . . . . . . . . . . . . . . . . . . . . Powered Fuel Flow Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . Powered Fuel Flow Transmitter 2 . . . . . . . . . . . . . . . . . . . . . . . Fuel Flow Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil Quantity Indicating Schematic . . . . . . . . . . . . . . . . . . . . . . . Different Types of Quantity Transmitter . . . . . . . . . . . . . . . . . . Capacitance Type Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . Reed Switch Type Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . Oil Pressure Indication System Schematic . . . . . . . . . . . . . . . Oil Pressure Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Low Oil Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pressure Tr Transmitter & Low Pr Pressure Sw Switch Lo Location . . . . .

3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71

Figure Figure Figure Figure Figure Figure

36 36 37 38 39 40 40 41

Oil Temperature Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil Temperature Sensor Location . . . . . . . . . . . . . . . . . . . . . . . Oil Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Spectrometric Oil Analysis Program . . . . . . . . . . . . . . . . . . . . . Magnetic Chip Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electronic Magnetic Chip Detectors . . . . . . . . . . . . . . . . . . . . .

73 75 77 79 81 83

EJAMF M14.02 B2 E

TABLE OF FIGURES

EJAMF M14.02 B2 E

TABLE OF FIGURES

EJAMF M14.02 B2 E

TABLE OF FIGURES

Propulsion Engine Indication Systems.pdf

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