Hydraulic System Flashcards
What do the hydraulic systems power?
- Flight controls
- Spoilers
- Landing Gear
- Nose wheel steering
- Wheel brakes
- Thrust reversers
What must be checked by the captain during the originating flow in regards to hydraulics?
All three hydraulic systems must be checked for pressure, temperature and quantity. If the quantity indication is CYAN, the reservoir must be refilled.
What is EDP 1?
Engine Driven Pump 1
The primary pump for hydraulic system 1. It is generally on when the engine is running.
What is ACMP 1?
AC Motor Pump 1
It is primarily a backup to EDP 1.
What are ACMP 3A and 3B?
Hydraulic system 3 is powered by two ACMPS.
ACMP 3A is the primary pump.
ACMP 3B serves as a backup in flight only.
What is the PTU?
Power Transfer Unit.
Assists in the landing gear extension and retraction in the event that:
- EDP 2 fails
- Engine 2 fails
How does the PTU get its power?
By transferring flow rate from EDP 1 and mechanically transferring that flow rate to the hydraulic fluid in system 2. It is all mechanical and requires no AC power.
What is ACMP 2?
AC Motor Pump 2.
Serves as a backup to EDP 2.
What is the Emergency/Parking Brake Accumulator?
It stores hydraulic pressure from system 1 and 2 for the sole use of the emergency/parking brake.
If hydraulic system 1 and 2 become depressurized, the accumulator provides enough pressure for 6 brake applications.
When does ACMP 1 automatically turn on?
During takeoff when:
- Flaps set greater than 0 and
- 50 kts ground speed OR thrust levers TOGA.
In flight when:
- Flaps greater than 0 or
- EDP 1 failure or
- Engine 1 failure
When is a certain time that you would turn ACMP 1 on?
When single engine taxiing with ENG 2.
When does ACMP 2 automatically turn on?
Single Engine Taxi with ENG 1 (parking brake must be released or set within last 6 minutes)
During takeoff when:
- Flaps set greater than 0 and
- 50 kts ground speed OR thrust levers TOGA
During flight when:
- Flaps greater than 0 or
- EDP 2 failure or
- ENG 2 failure
When does ACMP 3B automatically turn on?
When ACMP 3A fails in flight only.
Which hydraulic system powers nosewheel steering?
System 2
The PTU requires how much quantity in system 1?
12%
