Turbine Operation Instruments/maint Overhaul

Question 1

Why are compressor washes performed?

Answer 1

To remove contaminants using fluid wash and abrasive grit wash.

Question 2

How can you tell if a turbo fan or turbo jet engine is out of trim?

Answer 2

High EGT at the target EPR for takeoff power.

Question 3

What are the different types of compressor blade damage that may be found during inspection?

Answer 3

Dents, cracks, galling, pitting, scratches, burrs, burns, and gouges.

Question 4

What kind of markers can be used to mark the parts in hot and cold sections during repair?

Answer 4

Layout die, a felt tip marker, or chalk.

Question 5

How does relative humidity affect turbine engines?

Answer 5

Negligible effects.

Question 6

What criteria determines the replacement of life limited turbine engine components?

Answer 6

Cycles, hours, and/or calendar time.

Question 7

If turbine blades are removed from a turbine disk, why should they be reinstalled in the same location?

Answer 7

To maintain the balance of the turbine wheel.

Question 8

How are gas turbine engine tachometers calibrated?

Answer 8

In percent RPM.

Question 9

What is the engine pressure ratio on a turbine engine and what does it indicate?

Answer 9

Ratio between the total inlet pressure and the total turbine exhaust pressure, used to indicate thrust developed by the engine.

Question 10

What does exhaust gas temperature (EGT) indicate on a turbine engine and how is it obtained?

Answer 10

EGT is the average temperature of the discharge gases and is obtained by thermocouples near the turbine exit.

Question 11

Can the EGT system on a turbine engine be checked without running the engine?

Answer 11

Yes, by checking the resistance of thermocouples and circuits.