M15.14 Engine Indication Systems Flashcards
Why do we require exhaust gas temperature (EGT) indication?
To monitor temps experienced by the turbine engines to prevent thermal damage and indicate when a limit is exceeded
What is the temperature called where the hot gas hits the high pressure turbine?
Turbine inlet temperature (TIT)
What is the temperature called where the hot gas hits the high pressure turbine?
Turbine inlet temperature (TIT)
Where is the exhaust gas temperature indicator?
In the flight deck
What temperature does the EGT show?
The average temperatures measured by the individual thermocouples
The EGT indicator is in what type of unit?
Hermetically sealed unit
What do the sets of thermocouples do for the TIT?
One set is paralleled to transmit signals to the flight deck indicator
The other set provides temperature signals to engine monitoring and control systems
Three groups of engine indications?
Performance indications
System indications
Engine trend monitoring
What are system indications?
Also called secondary indications
Used to monitor the operation of engine systems such as oil and fuel
Detect malfunctions quickly
What is engine trend monitoring?
Uses engine parameters that are automatically recorded by the aircraft condition monitoring system (ACMS)
What two values are used to measure thrust?
The rotational speed of the fan (N1)
The engine pressure ratio (EPR)
The engine system indications monitor what systems?
Oil quantity
Oil pressure
Oil temperature
What type of warnings would appear on ECAM detected by the engine system indications?
When an indication exceeds a limit
When the system detects low pressure
When a filter becomes clogged
When an unlocked thrust reverser is detected
Three types of engine trend monitoring analysis?
The thermodynamic analysis
The mechanic- dynamic analysis
The oil consumption analysis
The engine pressure ratio (EPR) indicator gauge compares what?
Engine turbine discharge pressure to the pressure of the ram air at the inlet of engine
How is EPR determined?
Pressure measurements taken by probe installed in engine inlet and turbine exhaust
Two displays on EPR display?
Amber or red line that shows maximum available thrust
Blue line that shows the actual throttle position
What is FLEX?
An Airbus setting for the standard take off thrust setting.
Used to preserve engine wear and prolong engine life
Two main types of oil pressure transmitters?
The bourdon tube type
The strain gauge type
Strain gauges are often used in what type of circuit?
Wheatstone bridge circuit
If the oil pressure decreases below a limit what does the low oil pressure switch do?
The switch closes and a signal is sent to the flight warming computer and a warning message appears on the display unit in the flight deck
An oil inlet temperature indicator is used to indicate what?
Indicates the temperature of the oil as it enters the oil pressure pump
How does the oil temperature sensor work?
Designed to respond to changes in temperature and convert them into an electrical signal
Does fuel pressure require a warning if it falls outside normal operating range?
Yes
The fuel flow indicating system provides what two different indications to the flight crew?
The actual fuel flow to the engines
The fuel used since the engine was started
3 parts of rotor speed indication?
The sensor
The data transmission
The indication
Two types of sensors to measure rotor speed on engines?
Variable reluctance type sensor
Tachometer generator type- located in gearbox
What is a tachometer generator?
Has a permanent magnet that is driven by the gearbox
Driven at a speed proportional to the n2 rotor speed.
Where does the tachometer generator send the 3 phase AC voltage to?
FADEC computer
Three types of rotor speed indications?
Display with clock type scale
Display with moving vertical bar
The classical electromechanical indicator
On modern engines, if the engine speed exceeds the n1 redline, what happens?
The duration of the overspeed and the speed are recorded and reported to the engine trend monitoring
Main parts of engine vibration monitoring system?
The indication in the flight deck shows the level of vibration
One or two vibration sensors
Computer collects and filters vibration data for indication and trend monitoring
What are the engine vibration sensors?
Accelerometers that measure radial acceleration of the rotor system
Where are the two engine vibration sensors located on the engine?
One in the compressor area, near the N1 shaft
Second sensor is in the turbine area
Two types of accelerometers?
Electromagnetic accelerometer
Piezoelectric crystal type sensor
What is vibration indication on modern aircraft automatically controlled by?
The engine vibration monitoring unit
A typical electrical torque meter system consists of what?
A torque meter assembly, a phase director and an indicator
