Engine Exhaust and Thrust Reverser Systems Flashcards
How does a leak appear in an engine exhaust system?
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 an exhaust system for leaks?
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?
Bellows and ball joints prevent leakage while allowing contraction and expansion.
What type of damage is most common in the exhaust system of a reciprocating engine?
Cracks caused by expansion and contraction.
Should a turbocharged engine be started with the waste gate open or closed?
Open, so as much exhaust as possible will bypass the turbine.
Why are thrust reversers not normally used when the airplane is moving below approximately 60 knots?
There is a danger of recirculating the exhaust gases, and of the engine ingesting foreign objects stirred up by the high-velocity gases.
What is a mechanical-blockage thrust reverser?
A thrust reverser that slides a pair of scoop-shaped doors aft and opens them so they block the rearward flow of gases and deflect the gases forward.
How does a cascade-type thrust reverser operate?
A portion of the fan cowl moves rearward, and a series of blocker doors deflect the fan discharge air through fan cascades that direct the discharge air forward. At the same time, blocker doors shut off the flow of gases from the core engine and deflect it through cascades that direct it forward.
