Hydraulic Flashcards
How many hyd pumps are on the airplane?
6 total:
2 Eng driven pumps
4 AC motor pumps
(PTU makes 7 pumps)
How many hydraulic systems are on the airplane?
3 independent systems
What are the 6 systems that use hydraulic power?
SNLWTF
2. Spoilers
4. Nose wheel steering
3. Landing Gear
5. Wheel Brakes
6. Thrust Reversers
1. Flight Controls
Can hydraulic fluid be transferred between each system?
No
What are the 3 basic components of the hydraulic systems?
- Reservoir
- Pumps
- Accumulators
What is the purpose of the accumulators?
- Helps to maintain constant pressure by covering transient
demands - Helps to avoid cavitation in reservoir
When will Hyd ACMP 1 or 2 activate on ground and in flight?
Ground:
Ground:
1. Flaps > 0
2. TL set to T/O, or
3. GS > 50 kts
Takeoff:
in TOGA, activated for 60 seconds to avoid abrupt hydraulic
pressure variations in an event of engine failure
In-flight:
1. Eng or EDP failure
2. Flaps > 0
Hydraulic System 1
Rudder (Upper Actuator)
Elevator (L Outboard)
Thrust Reverser (Engine 1)
Multi-Function Spoilers (L & R panels 3 & 4)
Ground Spoilers (L & R panel 2)
Outboard Brakes
Emergency Parking Brake
Hydraulic System 2
Elevator (L & R Inboard)
Ailerons (L & R Inboard)
Thrust Reverser (Engine 2)
Multi-Function Spoilers (L & R panels 5)
Ground Spoilers (L & R panel 1)
Brakes (Inboard)
Landing Gear
Nose Wheel Steering
Emergency Parking Brake
Hydraulic System 3
Elevator (R Outboard)
Rudder (Lower Actuator)
Ailerons (L & R Outboard)
What are some of the important systems run on HYD 2?
- Landing gear
- Inboard brakes
- Nose-wheel steering
What is the PTU?
What is the PTU?
The power transfer unit (PTU) is a mechanical pump that uses
HYD 1 POWER to provide HYD 2 PRESSURE
What is the primary purpose of the PTU?
What is the primary purpose of the PTU?
Allows for landing gear retraction and extension in the event that
ENG 2 or EDP 2 fails
When will the PTU automatically activate?
If system meets requirements
When will the PTU automatically activate?
If system meets requirements
During takeoff and landing with flaps > 0, if
- Flaps > 0
- Eng 1 not fail
- Hyd 2 Reservoir Fluid Level above 12%
then PTU comes on automatically - ENG 2 or EDP Fail
How is single engine taxi possible if nose wheel steering is
on HYD 2?
How is single engine taxi possible if nose wheel steering is
on HYD 2?
Releasing the parking brake commands ACMP 2 to turn on