# Turbine Theory Final Exam.txt

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1. ﻿1 (8108) - At what point in an axial-flow turbojet engine will the highest gas pressures occur?
At the compressor outlet.
2. 2 (8109) - One function of the nozzle diaphragm in a turbine engine is to
Direct the flow of gases to strike the turbine blades at the desired angle.
3. 3 (8110) - What is the profile of a turbine engine compressor blade?
A cutout that reduces blade tip thickness.
4. 4 (8111) - The fan rotational speed of a dual axial compressor forward fan engine is the same as the
low-pressure compressor.
5. 5 (8112) - The abbreviation Pt7 used in turbine engine terminology means
the total pressure at station No. 7.
6. 6 (8113) - The blending of blades and vanes in a turbine engine
should be performed parallel to the length of the blade using smooth contours to minimize stress points.
7. 7 (8114) - What turbine engine section provides for proper mixing of the fuel and air?
Combustion section.
8. 8 (8115) - In a gas turbine engine, combustion occurs at a constant
pressure.
9. 9 (8116) - Which statement is true regarding jet engines?
At the higher engine speeds, thrust increases rapidly with small increases in RPM.
10. 10 (8117) - Some high-volume turboprop and turbojet engines are equipped with two-spool or split compressors. When these engines are operated at high altitudes, the
low-pressure rotor will increase in speed as the compressor load decreases in the lower density air.
11. 11 (8118) - Turbine nozzle diaphragms located on the upstream side of each turbine wheel, are used in the gas turbine engine to
increase the velocity of the heated gases flowing past this point.
12. 12 (8119) - Where is the highest gas pressure in a turbojet engine?
In the entrance of the burner section.
13. 13 (8120) - An exhaust cone placed aft of the turbine in a jet engine will cause the pressure in the first part of the exhaust duct to
increase and the velocity to decrease.
14. 14 (8121) - What is the function of the stator vane assembly at the discharge end of a typical axial-flow compressor?
To straighten airflow to eliminate turbulence.
15. 15 (8122) - The turbine section of a jet engine
drives the compressor section.
16. 16 (8123) - When starting a turbine engine,
a hot start is indicated if the exhaust gas temperature exceeds specified limits.
17. 17 (8124) - In the dual axial-flow or twin spool compressor system, the first stage turbine drives the
N(2) compressor.
18. 18 (8125) - During inspection, turbine engine components exposed to high temperatures may only be marked with such materials as allowed by the manufacturer. These materials generally include
1. layout dye. 2. commercial felt tip marker. 4. chalk. 1, 2, and 4.
19. 19 (8126) - When starting a turbine engine, a hung start is indicated if the engine
fails to reach idle RPM.
20. 20 (8127) - What are the two basic elements of the turbine section in a turbine engine?
Stator and rotor.
21. 21 (8128) - The function of the exhaust cone assembly of a turbine engine is to
straighten and collect the exhaust gases into a solid exhaust jet.
22. 22 (8129) - What are the two functional elements in a centrifugal compressor?
Impeller and diffuser.
23. 23 (8130) - What must be done after the fuel control unit has been replaced on an aircraft gas turbine engine?
Retrim the engine.
24. 24 (8131) - If, during inspection at engine overhaul, ball or roller bearings are found to have magnetism but otherwise have no defects, they
must be degaussed before use.
25. 25 (8132) - A turbine engine compressor which contains vanes on both sides of the impeller is a
double entry centrifugal compressor.
26. 26 (8133) - What is the first engine instrument indication of a successful start of a turbine engine?
A rise in the exhaust gas temperature.
27. 27 (8134) - Some engine manufacturers of twin spool gas turbine engines identify turbine discharge pressure in their maintenance manuals as
Pt7.
28. 28 (8135) - Who establishes the recommended operating time between overhauls (TBO) of a turbine engine used in general aviation?
The engine manufacturer.
29. 29 (8136) - The basic gas turbine engine is divided into two main sections: the cold section and the hot section.
(2) The hot section includes the combustor, diffuser, and exhaust sections. only No. 2 is true.
30. 30 (8137) - (1) Welding and straightening of turbine engine rotating airfoils does not require special equipment. (2) Welding and straightening of turbine engine rotating airfoils is commonly recommended by the manufacturer. Regarding the above statements,
neither No. 1 nor No. 2 is true.
31. 31 (8138) - Turbine engine components exposed to high temperatures generally may NOT be marked with
3. wax or grease pencil. 5. graphite lead pencil. 3 and 5.
32. 32 (8139) - Who establishes mandatory replacement times for critical components of turbine engines?
The engine manufacturer.
33. 33 (8140) - Main bearing oil seals used with turbine engines are usually what type(s)?
Labyrinth and/or carbon rubbing.
34. 34 (8141) - How does a dual axial-flow compressor improve the efficiency of a turbojet engine?
Higher compression ratios can be obtained.
35. 35 (8142) - Three types of turbine blades are
impulse, reaction, and impulse-reaction.
36. 36 (8143) - Which statements are true regarding aircraft engine propulsion?
1. An engine driven propeller imparts a relatively small amount of acceleration to a large mass of air. 2. Turbojet and turbofan engines impart a relatively large amount of acceleration to a smaller mass of air. 1, 2.
37. 37 (8144) - An advantage of the axial-flow compressor is its
high peak efficiency.
38. 38 (8145) - What is one purpose of the stator blades in the compressor section of a turbine engine?
Control the direction of the airflow.
39. 39 (8146) - What is the purpose of the diffuser section in a turbine engine?
To increase pressure and reduce velocity.
40. 40 (8147) - Where do stress rupture cracks usually appear on turbine blades?
Across the leading or trailing edge at a right angle to the edge length.
41. 41 (8148) - In which type of turbine engine combustion chamber is the case and liner removed and installed as one unit during routine maintenance?
Can.
42. 42 (8149) - The diffuser section of a jet engine is located between
the compressor section and the burner section.
43. 43 (8150) - When the leading edge of a first-stage turbine blade is found to have stress rupture cracks, which of the following should be suspected?
Overtemperature condition.
44. 44 (8151) - Turbine blades are generally more susceptible to operating damage than compressor blades because of
exposure to high temperatures.
45. 45 (8152) - Which of the following is the ultimate limiting factor of turbine engine operation?
Turbine inlet temperature.
46. 46 (8153) - The recurrent ingestion of dust or other fine airborne particulates into a turbine engine can result in
erosion damage to the compressor and turbine sections.
47. 47 (8154) - Which of the following engine variables is the most critical during turbine engine operation?
Turbine inlet temperature.
48. 48 (8155) - Reduced blade vibration and improved airflow characteristics in gas turbines are brought about by