M15.7 (thrust Reversers) Flashcards
Does a a/c need a thrust reverser?
No the brakes are sufficing enough
How does a reverse thruster produce braking force?
By deflecting exhaust gas in the opposite direction
What is the ideal angle for a thrust reverser?
180 degrees
At what angle is air deflected forward on a cold stream thrust reverser?
45 to 60 degrees
What are the 4 types of thrust reverse systems?
Clamshell
Bucket
Translating cowling
Pivoting door
How is the clamshell door operated?
Pneumatically
What a/c will you find a clamshell door on?
Old a/c
How is the bucket door operated?
Hydraulically
On a modern fan reverser what air is deflected?
Cold fan air
What is a blocker door?
A door that closes of fan discharge so all fan air only discharges through cascade vanes
How is the pivoting door actuated?
Hydraulically
What are the negatives on reverser operation?
Doesn’t operate well at low speeds
Compressor can stall
Engine can invest its own thrust
Can cause a air cushion bellow the wing
Whirls up a lot of dust and dirt
What is done to the airflow to minimise the disadvantages?
Reverse airflow is matched to the engine position
What problem can occur with 4 engine a/c?
Inboard engines can blow into outboard engines
What do engines use to direct airflow in the correct direction?
Cascade vanes
What must be done to a faulty thrust reverser?
Must be de activated
What does the control system do?
Activates thrust reverser and increases engine power for reverse thrust
What does the reverser actuation system do?
Moves airflow deflection mechanism by signals from the reverser control system
What does the airflow deflection system do?
Deflects air flow in optimum position for safe reveres thrust
What does the thrust reverser interlock do?
Ensures engine power is only increased after reverser is fully deployed
What 3 parts make up a thrust reverse system?
Control system
Actuation system
Deflection system
What are the 2 means of actuating a thrust reverser?
Hydraulic and pneumatic
What reverser systems have a actuation system?
Reverse thruster with a large blocker door
The pneumatic reverser only used on what reverser systems?
Cascade type
Cam shell type
What is the purpose of the locking system?
Ensure reverser is kept locked in its stowed position
How does the lock mechanism work?
By using a hook to hold it in place
Cascade vanes are bolted to what?
A fixed part of the reverser cowling
Cascade vanes can deflect air at what angles?
45degree upwards
45degree downward
90degree straight
What happens if you put a RH upward pointing cascade vane on the LH side?
It will point downwards
What does a amber indication for the thrust reverser system indicate?
Reverser is moving to deployed or stowed position
What 2 methods are available for latching hydraulically operated T/R doors in position?
Latch mechanism
Locks in the actuator
What does a reverser unlock message indicate?
Reverser not safe in stowed position
What does a green light show?
Reverser gulley deployed so thrust can be applied
