Questions and Answers - Aircraft Engine Exhaust and Reverser Systems | Aircraft Systems

Questions and Answers - Aircraft Engine Exhaust and Reverser Systems

1. Why is high nickel chromium steel used in many exhaust systems?
a. High heat conductivity and flexibility.
b. Corrosion resistance and low expansion coefficient.
c. Corrosion resistance and high heat conductivity.

2. Reciprocating engine exhaust system designs commonly used to provide for ease of installation and/or allow for expansion and contraction, may include the use of
1. spring loaded ball/flexible joints.
2. slip joints.
3. bellows.
4. flexible metal tubing.

a. 1, 2, 3, and/or 4.
b. 1, 2, and/or 4.
c. 1, 2, and/or 3.

3. One source commonly used for carburetor air heat is
a. turbocharger heated air.
b. alternate air heat.
c. exhaust gases.

4. The hot section of a turbine engine is particularly susceptible to which of the following kind of damage?
a. Galling.
b. Pitting.
c. Cracking.


5. What is the purpose of a slip joint in an exhaust collector ring?
a. It aids in alignment and absorbs expansion.
b. It reduces vibration and increases cooling.
c. It permits the collector ring to be installed in one piece.

6. Sodium-filled valves are advantageous to an aviation engine because they
a. are lighter.
b. dampen valve impact shocks.
c. dissipate heat well.

7. What type nuts are used to hold an exhaust system to the cylinders?
a. Brass or heat-resistant nuts.
b. High-temperature fiber self-locking nuts.
c. High-temperature aluminum self-locking nuts.

8. Repair of exhaust system components
a. is impossible because the material cannot be identified.
b. must be accomplished by the component manufacturer.
c. is not recommended to be accomplished in the field.

9. On turbojet powered airplanes, thrust reversers are capable of producing between?
a. 35 and 50 percent of the rated thrust in the reverse direction.
b. 35 and 75 percent of the rated thrust in the reverse direction.
c. 35 and 65 percent of the rated thrust in the reverse direction.

10. On an aircraft that utilizes an exhaust heat exchanger as a source of cabin heat, how should the exhaust system be inspected?
a. X-rayed to detect any cracks.
b. Hydrostatically tested.
c. With the heater air shroud removed.

11. How should ceramic-coated exhaust components be cleaned?
a. With alkali.
b. By degreasing.
c. By mechanical means.

12. Which of the following indicates that a combustion chamber of a jet engine is not operating properly?
a. Clam shells stick in thrust reverse position.
b. Hot spots on the tail cone.
c. Warping of the exhaust duct liner.


13. Select a characteristic of a good weld on exhaust stacks.
a. The weld should be built up 118 inch.
b. Porousness or projecting globules should show in the weld.
c. The weld should taper off smoothly into the base metal.

14. How do the turbines which are driven by the exhaust gases of a turbo-compound engine contribute to total engine power output?
a. By driving the crankshaft through suitable couplings.
b. By driving the supercharger, thus relieving the engine of the supercharging load.
c. By converting the latent heat energy of the exhaust gases into thrust by collecting and accelerating them.

15. How should corrosion-resistant steel parts such as exhaust collectors be blast cleaned?
a. Use steel grit which has not previously been used on soft iron.
b. Use super fine granite grit.
c. Use sand which has not previously been used on iron or steel.

16. Power recovery turbines used on some reciprocating engines are driven by the
a. exhaust gas pressure.
b. crankshaft.
c. velocity of the exhaust gases.

17. Reciprocating engine exhaust systems that have repairs or sloppy weld beads which protrude internally are unacceptable because they cause
a. base metal fatigue.
b. localized cracks.
c. local hot spots.

18. Ball joints in reciprocating engine exhaust systems should be
a. tight enough to prevent any movement.
b. disassembled and the seals replaced every engine change.
c. loose enough to permit some movement.

19. All of the following are recommended markers for reciprocating engine exhaust systems except
a. India ink.
b. lead pencil.
c. Prussian blue.

20. How are combustion liner walls cooled in a gas turbine engine?
a. By secondary air flowing through the combustion chamber.
b. By the pattern of holes and louvers cut in the diffuser section.
c. By bleed air vented from the engine air inlet.

21. Augmenter tubes are part of which reciprocating engine system?
a. Induction.
b. Exhaust.
c. Fuel.

22. Dislodged internal muffler baffles on a small reciprocating engine may
a. obstruct the muffler outlet and cause excessive exhaust back pressure.
b. cause the engine to run excessively cool.
c. cause high fuel and oil consumption.


23. What i s the purpose of an exhaust outlet guard on a small reciprocating engine?
a. To prevent dislodged muffler baffles from obstructing the muffler outlet.
b. To reduce spark exit.
c. To shield adjacent components from excessive heat.

24. What could be a result of undetected exhaust system leaks in a reciprocating engine powered airplane?
a. Pilot/passenger incapacitation caused by carbon monoxide entering the cabin.
b. A rough-running engine with increased fuel consumption.
c. Too low exhaust back pressure resulting in the desired power settings not being attained.

25. How may reciprocating engine exhaust system leaks be detected?
a. An exhaust trail aft of the tailpipe on the airplane exterior.
b. Fluctuating manifold pressure indication.
c. Signs of exhaust soot inside cowling and on adjacent components.

26. Compared to normally aspirated engines, turbocharged engine exhaust systems operate at
a. similar temperatures and higher pressures.
b. higher temperatures and higher pressures.
c. similar temperatures and pressures.

27. Most exhaust system failures result from thermal fatigue cracking in the areas of stress concentration. This condition is usually caused by
a. the drastic temperature change which is encountered at altitude.
b. improper welding techniques during manufacture.
c. the high temperatures at which the exhaust system operates.

28. Thrust reversers utilizing a pneumatic actuating system usually receive operating pressure from
a. the engine bleed air system.
b. an on board hydraulic or electrical powered compressor.
c. high pressure air reservoirs.

29. Operating thrust reversers at low ground speeds can sometimes cause
1. sand or other foreign object ingestion.
2. hot gas re-ingestion.
3. compressor stalls.

a. 1, 2, and 3.
b. 1 and 2.
c. 2 and 3.

30. Engines using cold stream, or both cold and hot stream reversing include
a. high bypass turbofans.
b. turbojets.
c. turbojets with afterburner.

31. The purpose of cascade vanes in a thrust reversing system is to
a. form a solid blocking door in the jet exhaust path.
b. turn the exhaust gases forward just after exiting the exhaust nozzle.
c. turn to a forward direction the fan and/or hot exhaust gases that have been blocked from exiting through the exhaust nozzle.

32. Turbojet and turbofan thrust reverser systems are generally powered by
1. fuel pressure.
2. electricity.
3. hydraulic pressure.
4. pneumatic pressure.

a. 1, 3, and 4.
b. 1, 2, and 3.
c. 2, 3, and 4.

33. The rearward thrust capability of an engine with the thrust reverser system deployed is
a. less than its forward capability.
b. equal to or less than its forward capability, depending on ambient conditions and system design.
c. equal to its forward capability.

34. Which statement is generally true regarding thrust reverser systems?
a. It is possible to move some aircraft backward on the ground using reverse thrust.
b. Engine thrust reversers on the same aircraft usually will not operate independently of each other (must all be simultaneously).
c. Mechanical blockage system design permits a deployment position aft of the exhaust nozzle only.

35. What is the proper operating sequence when using thrust reversers to slow an aircraft after landing?
a. Advance thrust levers up to takeoff position as conditions require, select thrust reverse, deselect thrust reverser, retard thrust levers to ground idle.
b. Retard thrust levers to ground idle, raise thrust reverser levers as required, and retard thrust levers to ground idle.
c. Select thrust reverse, advance thrust reverser levers no higher than 75% N1, and retard thrust reverser levers to idle at approximately normal taxi speed.



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