engine exhaust and reverser systems

Question 1

how are high temperature noxious gases removed and disposed of in an operating reciprocating engine

Answer 1

by the engine exhaust system

Question 2

what is the primary function of an exhaust system (in regard to saftey)

Answer 2

to provide protection against the potentially destructive action of exhaust gases

Question 3

what are two types of reciprocating engine exhaust systems

Answer 3

the short stack system and the collector system

Question 4

what type of exhaust system is used on turbocharged engines

Answer 4

the collector system

Question 5

what material is typically used to make exhaust system muffler shrouds

Answer 5

stainless steel

Question 6

what drawback in using collector-type exhaust systems is more than offset when used on turbocharged engines

Answer 6

the loss of horsepower due to exhaust system back pressure

Question 7

why is exhaust system failure considered a severe hazard

Answer 7

it can result in carbon monoxide poisoning, loss of engine power, or fire

Question 8

why should lead, zinc, or galvanized marks not be made on exhaust systems?

Answer 8

the marks cause a change in molecular structure when heated ad will cause cracks

Question 9

what is an indication of an exhaust gas leak

Answer 9

flat gray or a sooty black deposit in the area of the leak

Question 10

how are exhaust system internal baffles of diffusers inspected

Answer 10

the exhaust system is disassembled as necessary for visual inspection

Question 11

how can failure of exhaust system internal baffles or diffusers cause a loss of engine power

Answer 11

by restricting the flow of exhaust gasses

Question 12

what happens to engine power when a heat exchanger leaks exhaust gasses into the engine induction system?

Answer 12

loss of power

Question 13

where are exhaust manifold and stack failures usually found

Answer 13

at welded or clamped points, and flanges

Question 14

what is a common cause of turbocharger waste gate sticking

Answer 14

coke deposits or carbon buildup

Question 15

why are turbocharged exhaust system leaks very damaging at high altitudes

Answer 15

pressure differential will cause the leak to escape with torch-like intensity

Question 16

what are exhaust system coke deposits

Answer 16

excessive carbon buildup

Question 17

what happens to turbine engine performance if the exhaust nozzle area is changed

Answer 17

the performance and engine gas temperature change

Question 18

what are the components of a typical turbine exhaust nozzle

Answer 18

a tail cone, exhaust duct, and support struts

Question 19

what is the function of the thermocouple probes in a turbine exhaust pipe

Answer 19

to measure exhaust gas temperature

Question 20

what change does noise suppressor make to noise frequency in order to help reduce older turbojet engine noise

Answer 20

it converts low frequency sound into high frequency sound

Question 21

what are thrust reversers primarily used for

Answer 21

to aid in decelerating an aircraft after landing

Question 22

name two types of thrust reverser systems commonly used

Answer 22

mechanical blockage (clamshell),
aerodynamic blockage ( cascade)

Question 23

what are hazards of operating some thrust reversers at low ground speeds

Answer 23

1. re-ingestion of hot exhaust gases
2. ingestion of foreign objects stirred up by the deflected exhaust gases

Question 24

are thrust reversers generally able to produce maximum reverse thrust approximately equal to an engine’s full forward thrust

Answer 24

no. an engines full reverse thrust is usually substantially less than its full forward thrust