Hydraulic System Flashcards
What is the T-6 hydraulic system pressurized to?
3000 +- 120 psi
What devices does the primary hydraulic system operate in normal flight operations?
- Landing gear and main landing gear inboard doors
- Flaps
- Speed brake
- Nose wheel steering
Where are most of the hydraulic system components located?
Hydraulic service bay on the lower right side just behind the wing
At what pressure will the hydraulic system allow operation?
> 1800 psi
What is the purpose of the engine-driven pump?
Creates and distributes pressure to the hydraulic system
What is the purpose of the reservoir?
Provides pressurized fluid back to the pump to the keep the pump “charged” with fluid
What is the purpose of the reservoir piston?
Steps down the return side of the reservoir to 50 psi to prevent damage to the pump
What is the purpose of the reservoir cylinder?
Prevents foaming of the fluid due to low pressure, maintains 50 psi in the reservoir
What is the purpose of the Pressure Release Valve?
Helps avoid any damage caused by hydraulic overpressure
What psi does the pressure release valve operate at?
3250 to 3500 psi
What is the purpose of the slide valve?
Isolate the hydraulic pressure coming from the engine-driven pump, through the power package, from the rest of the hydraulic system when the emergency system is activated
What will activate the emergency hydraulic system?
Pulling the landing gear emergency extension handle
Can you return to normal operation once the landing gear emergency extension handle is pulled?
No, maintenance must reset the handle and emergency selector manifold
What is the purpose of the selector manifold?
Operates the appropriate electrical selector valve
What are normal operating limits for hydraulic pressure?
2880 to 3120 psi
What happens if the hydraulic fluid level in the reservoir drops below one quart?
- The amber HYDR FL LO annunciator illuminates
- MASTER CAUTION illuminates
- Aural tone
When will the emergency system be used?
- In the event of a primary hydraulic system failure
- In the event of engine failure
- In the event of battery bus failure
What does the emergency system allow?
A one-time lowering of the landing gear and main gear inboard doors, and the flaps
When is the emergency package pressurized?
At engine startup
What happens if the emergency accumulator drops below 2400 +- 150 psi?
- Amber EHYD PX LO annunciator illuminates
- MASTER CAUT
- Aural tone
How is power provided for the landing gear?
LDG GR CONT circuit breaker on the batter bus in the front cockpit
Approximately how long does it take for normal gear extension/retraction?
6 seconds
What airspeed must you be below to operate the landing gear and/or flaps?
150 KIAS
What kind of flaps does the T-6 use?
Split flaps, inboard and outboard
What are flaps used for?
Produce an increase or decrease in lift and drag
Which flap setting will give you the greatest amount of lift with the least amount of drag?
Takeoff
What provides power to the flap system?
FLAP CONT circuit breaker on the battery bus in the front cockpit
What has to happen before emergency flaps can be used?
The emergency landing gear handle must have been activated
What powers emergency flap operation?
Hot battery bus
What is the purpose of the speed brake?
- Decelerate
- Increase descent rate without increasing airspeed
What provides power to the speed brake?
SPEED BRAKE circuit breaker on the generator bus
When will the speed brake not extend?
If the flaps are already extended
Once extended, the speed brake will remain so until what happens?
- Speed brake switch is moved forward
- Flaps are extended to TO or LDG position
- PCL moved to MAX
What provides power to the nose wheel steering system?
NWS circuit breaker on the generator bus in the front cockpit
How far will the nose wheel move with NWS off?
80° in either direction
How far will the nose wheel move with NWS on?
12° in either direction
