EXHAUST AND REVERSER SYSTEMS

Question 1

What is an indication of an exhaust gas leak?

Answer 1

A flat gray or sooty (fuligem) black deposit in the area of the leak

Question 2

What is the purpose of the exhaust system?

Answer 2

To remove high temperature noxious gases

Question 3

Name two types of reciprocating engine exhaust systems:

Answer 3

The short stack and the collector system.

Question 4

What drawback (disadvantage) in using collector-type exhaust systems when used on turbocharged engines?

Answer 4

The loss of horse-power due to exhaust system back pressure.

Question 5

What could resut if the internal baffles or diffusers in an exhaus system fails?

Answer 5

The flow of the exhaust gases could be restricted, resulting in a los of engine power

Question 6

What type of exhaust system is used on turbocharged engines?

Answer 6

The collector system.

Question 7

Name the components of a typical turbine exhaust nozzle.

Answer 7

The tail cone, exhaust ducts and supports struts.

Question 8

How do you inspect the internal baffles and diffusers of an exhaust system?

Answer 8

By disassembling and visually inspecting the components.

Question 9

Why is an exhaust system failure considered severe hazard ?

Answer 9

It can result in carbon monoxide poisoning, loss of engine power and fire.

Question 10

What could happen if lead, zinc or galvanized marks are made on an exhaust system?

Answer 10

They cause a change in the molecular structure, which could result in cracks when heated.

Question 11

What kind of material is normally used to make the
muffler shrouds found in the exhaust system?

Answer 11

Stainless steel.

Question 12

What is a common cause of turbocharger waste gate sticking?

Answer 12

Coke deposits or carbon buildup.

Question 13

What are exhaust system coke deposits?

Answer 13

Excessive carbon buidup.

Question 14

What happens if the heat exchanger leaks exhaust gases into the induction system?

Answer 14

There is a loss of engine power.

Question 15

Where are the most common places to find cracks in an exhaust system?

Answer 15

At welded or clamped areas and at the flanges.

Question 16

Why are turbocharged exhaust system leaks very damaging at the right altitudes?

Answer 16

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

Question 17

What is the result of changing the exhaust nozzle area of a turbine engine?

Answer 17

The engine’s performance and exhaust gas temperature change.

Question 18

What is the purpose of thrust reversers?

Answer 18

They help decelerate an aircraft after landing.

Question 19

How does a noise supressor found on older turbojet engines work?

Answer 19

It converts low frequency sound, into high frequency sound ‘ thus reducing the sound footprint.

Question 20

What are the two most commonly used types of thrust reversers?

Answer 20

The clamshell (or mechanically blocked) and the Cascade (or aerodinamically blocked).

Question 21

How much thrust do the reversers produce compared to the engine’s full forward thrust?

Answer 21

Substantially less.

Question 22

What are the hazards of operating some thrust reversers at low ground speeds?

Answer 22

Ingestion of foreign objects.

Question 23

What is the primary function of an exhaust system ( in regard to safety)?

Answer 23

To provide protection against the potential destructive action of exhaust gases.

Question 24

What is the function of the thermocouple probes in a turbine exhaust tailpipe?

Answer 24

To measure EGT.