Hydraulics Flashcards
Which systems use hydraulic power?
Flt controls leading edge flaps/slats trailing edge flaps landing gear wheel brakes nose wheel steering thrust reversers autopilots
T/F: Airplane controllability is reduced with a single loss of sys A or sys B.
false. no reduction.
Where are the 3 hydraulic reservoirs?
in main wheel well.
Sys A and B incorporate a ______ that may prevent a total loss of system fluid should a leak develop.
standpipe
Which system services the standby system for pressurization?
Sys B supplies.
With pumps operating, what is normal hydraulic pressure?
3000 psi to a max of 3500 psi.
What does RF mean?
Hydraulic qty is below 76%. Only accurate with aircraft on ground and engines shut down or taxi-in with flaps up.
Sys A components:
Ailerons Rudder Elevator & elevator feel flight spoilers (2 on each wing) Ground spoilers Alt brakes No 1 Thrust reverser Autopilot A Normal nose wheel steering Landing gear Power Transfer Unit (PTU)
Sys B Components
Ailerons Rudder Elevator & Elevator Feel Flight Spoilers (2 on each wing) Leading edge flaps and slats Normal brakes No 2 thrust reverser Autopilot B Alternate nose wheel steering Landing gear transfer unit Autoslats Yaw damper Trailing Edge flaps
What types of pumps do Sys A and B have?
engine driven and electric. Engine driven pumps produce a flow rate 4x better than electric pumps.
Which generators supply power to the electric driven pumps?
Gen 1 supplies #2 elec pump
Gen 2 supplies #1 elec pump
How do the ENG hyraulic pumps work if their switches are moved off?
A blocking valve closes so fluid is isolated and the pump actually still works. Pump still rotates if engine is still on.
T/F: A minimum amount of fuel is req’d in each main tank for operation of the electric motor driven pumps
true
What do hydraulic LOW PRESSURE lights mean?
Low output pressure from either engine-driven or electric hydraulic pumps.
What is the purpose of the PTU?
automatically supply an additional volume of hydraulic fluid to the autoslats and leading edge flaps and slats.
When will the PTU work?
only operate when Sys B engine driven pump volume is lost.