Engine Exhaust and Reverser Systems

Question 1

Why is high nickel chromium steel used in many exhaust systems?

Answer 1

Corrosion resistance and low expansion coefficient.

Question 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 what?

Answer 2

spring loaded ball joints, slip joints, and bellows.

Question 3

One source commonly used for carburetor air heat is what?

Answer 3

exhaust gases.

Question 4

The hot section of a turbine engine is particularly susceptible to which of the following kinds of damage?

Answer 4

Cracking.

Question 5

What is the purpose of a slip joint in an exhaust collector ring?

Answer 5

it aids in alignment and absorbs expansion.

Question 6

Sodium-filled valves are advantageous to an aviation engine because they what?

Answer 6

dissipate heat well.

Question 7

What type of nuts are used to hold an exhaust system to the cylinders?

Answer 7

Brass or heat-resistant nuts.

Question 8

Repair of exhaust system components…

Answer 8

is not recommended to be accomplished in the field.

Question 9

One turbojet powered airplanes, thrust reversers are capable of producing between…

Answer 9

35 and 50 percent of the rated thrust in the reverse direction.

Question 10

On an aircraft that utilizes an exhaust heat exchanger as a source of cabin heat, how should the exhaust system be inspected?

Answer 10

With the heater air shroud removed.

Question 11

How should ceramic-coated exhaust components be cleaned?

Answer 11

By degreasing.

Question 12

Which of the following indicates that a combustion chamber of a jet engine is not operating properly?

Answer 12

Hot spots on the tail cone.

Question 13

Select a characteristic of a good weld on exhaust stacks.

Answer 13

The weld should taper off smoothly into the base metal.

Question 14

How do the turbines which are driven by the exhaust gases of a turbo-compound engine contribute to total engine power output?

Answer 14

By driving the crankshaft through suitable couplings.

Question 15

How should corrosion-resistant steel parts such as exhaust collectors be blast cleaned?

Answer 15

Use sand which has not previously been used on iron or steel.

Question 16

Power recovery turbines used on some reciprocating engines are driven by the what?

Answer 16

velocity of the exhaust gases.

Question 17

Reciprocating engine exhaust systems that have repairs or sloppy weld beads which protrude internally are unacceptable because they cause what?

Answer 17

local hot spots.

Question 18

Ball joint in reciprocating engine exhaust systems should be what?

Answer 18

loose enough to permit some movement.

Question 19

All of the following are recommended markers for reciprocating engine exhaust systems except…

Answer 19

lead pencil.

Question 20

How are combustion liner walls cooled in a gas turbine engine?

Answer 20

By secondary air flowing through the combustion chamber.

Question 21

Augmenter tubes are part of which reciprocating engine system?

Answer 21

Exhaust.

Question 22

Dislodged internal muffler baffles on a small reciprocating aircraft engine may cause what?

Answer 22

excessive exhaust back pressure.

Question 23

What is the purpose of an exhaust outlet guard on a small reciprocating engine?

Answer 23

To prevent dislodged muffler baffles from obstructing the muffler outlet.

Question 24

What could be a result of undetected exhaust system leaks in a reciprocating engine powered airplane?

Answer 24

Pilot/passenger incapacitation caused by carbon monoxide entering the cabin.

Question 25

How may reciprocating engine exhaust system leaks be detected?

Answer 25

Signs of exhaust soot inside cowling and on adjacent components.

Question 26

Compared to normally aspirated engines, turbo-charged engine exhaust systems operate at what?

Answer 26

higher temperatures and higher pressures.

Question 27

Most exhaust system failures result from thermal fatigue cracking in the areas of stress concentration. This condition is usually caused by what?

Answer 27

the high temperatures at which the exhaust system operates.

Question 28

Thrust reversers utilizing a pneumatic actuating system usually receive operating pressure from what?

Answer 28

the engine bleed air system.

Question 29

Operating thrust reversers at low ground speeds can sometimes cause…

Answer 29

hot gas re-ignition, compressor stalls, and sand or other foreign object ingestion.

Question 30

Engines using cold stream, or both cold and hot stream reversing, include what?

Answer 30

high bypass turbofans.

Question 31

The purpose of cascade vanes in a thrust reversing system is to what?

Answer 31

turn to a forward direction the fan and/or hot exhaust gases that have been blocked from exiting through the exhaust nozzle.

Question 32

Turbojet and turbofan thrust reversers systems are generally powered by what?

Answer 32

electricity, hydraulic pressure, and pneumatic pressure.

Question 33

The rearward thrust capability of an engine with the thrust reverser system deployed is what?

Answer 33

less than its forward capability.

Question 34

Which of the following statements is true regarding thrust reverser systems?

Answer 34

The reverser system must be able to withstand high temperatures, be mechanically strong, relatively light in weight, and reliable.

Question 35

What is the proper operating sequence when using thrust reversers to slow an aircraft landing?

Answer 35

Retard thrust levers to ground idle, raise thrust reverser levers as required, and retard thrust reverser levers to ground idle.