Hydraulics Flashcards
How many Hydraulic systems are on the airplane?
- 3 independent systems
- HYD 1, 2, and 3
What systems use Hydraulic power?
- Flight Controls
- Spoilers
- Landing Gear
- Nose wheel steering
- Wheel brakes
- Thrust Reversers
Can Hydraulic fluid be transferred between each system?
No
How many Hydraulic pumps are on the airplane?
6 Total
- 2 EDP’s (eng driven)
- 4 ACMP’s
What are the basic components of the hydraulic systems?
- Reservoir
- Pumps
- Accumulator
What is the purpose of the Accumulator?
- Helps maintain constant pressure by covering transient demands
- Helps to avoid pump cavitation
When will ACMP 1 or 2 automatically activate?
Ground
- Flaps > 0, and
-TL set to T/O, or
-Groundspeed > 50 knots
Flight
-Engine failure or EDP Failure
-Flaps > 0What are some important items controlled by HYD 2 system?
Landing Gear
Nosewheel steering
Inboard Brakes
What is the PTU?
Power Transfer unit
Mechanical pump that uses HYD 1 power to provide HYD 2 pressure to assist with gear operation
What is the primary purpose of the PTU?
To allow landing gear retraction in the event of engine 2 or EDP 2 failure
When will the PTU automatically activate?
- During Takeoff and landing with Flaps > 0, if
- Engine 2 or EDP 2 Fails
How is single engine taxi possible if nose wheel steering is on HYD 2?
Releasing the parking brake activates ACMP 2
What is the primary purpose of HYD 3?
Back-up for flight controls
Why are HYD ACMP 3A & B pump switch positions ON & AUTO respectively?
- HYD ACMP 3A pump is primary and has no automation
- HYD ACMP 3B pump is back up and automatically activates if ACMP 3A fails
What, if any, HYD ACMP will function if the RAT is the only power source?
HYD ACMP 3A only
