Turbine Engine Operation, Instruments, Maintenance and Overhaul Flashcards
Why are compressor washes performed and what methods are commonly used?
To remove any contaminants from the compressor section and improve performance. The fluid wash and abrasive grit wash are commonly used
How can you tell if a turbofan or turbojet engine is out of trim?
There will be a high egt at the target engine pressure ratio for takeoff power
Name the different types of compressor blade damage that may be found during inspection
Dents, cracks, galling, pitting, scratches, burrs, burns and gouges
What kind of markers can be used to mark hot and cold sections during repair?
Layout dye, a felt tip marker or chalk
How does relative humidity affect turbine engines?
The effects are negligible
What criteria determines replacement of life limited turbine engine components?
Cycles, hours and/or calendar time
If turbine blades are removed from a turbine disc, why should they be reinstalled in the same location?
To maintain the balance of the turbine wheel
How are gas turbine engine tachometers calibrated?
They are calibrated in %rpm
On a turbine engine, what is the engine pressure ratio and what does it indicate?
It is the ratio between the total inlet pressure and the total the total turbine exhaust pressure and is used to indicate the thrust developed by the engine
On a turbine engine, what does egt indicate and how is it obtained?
Egt is the average temperature of the turbine discharge gases and is obtained by thermal couples placed near the turbine exit
Can the egt system on a turbine engine be checked without running the engine?
Yes, by checking the resistance of the thermocouples and circuits
