13 - Hydraulics Flashcards
What is the purpose of the PTU, when does it operate?
It’s purpose is to power the AUTOSLATS.
Should there be a power loss in system b pressure, the system A pressure will power the autoslats through the PTU.
Which PCU will the stby rudder use?
The stby rudder PCU
When will RF be shown next to hydraulic quantity. During which stage of flight?
When quantity is below 76%. On the ground with both engines shut down, or after landing with flaps up during taxi in.
Which hydraulic system powers the thrust reversers?
A for engine 1, B for engine 2
When can hydraulic quantity vary?
Initial pressurization of the system, operating leading edge devices or operating gear.
What is foaming, and what would the indications be
If the system is not properly pressurized, it can start foaming at higher altitudes.
Can be recognized by pressure fluctuations.
If there is a leak in the standby system, what would system B quantity usually stabilize at
72%
What is the procedure if you get low pressure in nr1 engine hydraulic pump?
Pump off
When is the standby system low pressure light armed?
Only if the pump is activated manually or automatically
What can be an indicator of standby system leak?
The quantity in system B decreases
Which system normally powers the autoslats?
System B
The standby system can power which devices?
Both thrust reversers, rudder, autoslats, leading edge flaps and slats (lowering)
Even if system be loses pressure, one unit will still function:
The PTU
When will the landing gear transfer unit operate, how?
When system A engine-driven pump is lost, it will take pressure from system B to raise the landing gear if the gear is still down and selected up +
- airborne
- eng1 RPM drops below a limit value (engine failure)
