Engine Exhaust and Reverser Systems Flashcards
How does a leak appear in an engine exhaust system? (AM.III.L.K1)
It normally looks like a gray or black feather-shaped streak coming from a crack or from a location where components are not in perfect alignment.
How can you check a reciprocating engine exhaust system for leaks? (AM.III.L.K1)
Pressurize the exhaust system with the discharge from a vacuum cleaner and wipe a soap solution over all joints and suspect areas. A leak will cause bubbles to form.
How do the components in the exhaust system of a turbocharged engine allow for expansion and contraction due to heat, and at the same time prevent leakage? (AM.III.L.K1)
Bellows and ball joints prevent leakage while allowing contraction and expansion.
Should a turbocharged engine be started with the waste gate open or closed? (AM.III.L.K1)
Open, so as much exhaust as possible will bypass the turbine.
What is the primary function of a reciprocating engine exhaust system? (AM.III.L.K1)
To get rid of the hot gases released by the engine.
What is a short stack exhaust system? (AM.III.L.K1)
Straight pipe no mufflers.
The short stack system is generally used on non-supercharged engines and low-powered engines where the noise level is not too objectionable.
Why are thrust reversers not normally used when the airplane is moving below approximately 60 knots? (AM.III.L.K4)
The exhaust gases might flow back into the engine, and the engine could suck in debris or foreign objects stirred up by the fast-moving gases.
What is a mechanical blockage thrust reverser? (AM.III.L.K4)
A thrust reverser that moves a pair of scoop-shaped doors back, blocking the gases from going rearward and redirecting them forward.
How does a cascade type thrust reverser operate? (AM.III.L.K4)
A part of the fan cowl moves backward, and a set of blocker doors directs the fan air through fan cascades that push the air forward. At the same time, the blocker doors stop the flow of gases from the main engine and also send them forward using these channels.
