Hydraulics Flashcards
Electric Hydraulic Pump OVERHEAT Lights
Illuminated: Hydraulic fluid used to cool and lubricate the corresponding electric driven pump has overheated or the pump itself has overheated
Hydraulic Pump LOW PRESSURE Lights
Illuminated: output pressure of associated pump is low
ELECTRIC HYDRAULIC PUMPS switches
ON - provides power to associated electric motor-driven pump
OFF - electrical power removed from pump
ENGINE HYDRAULIC PUMP switches
ON - deenergizes blocking valve in pump to allow pump pressure to enter system
NOTE: should remain ON at shutdown to prolong solenoid life
OFF - energizes blocking valve to block pump output
Normal and Max pressure for the hydraulic system pressure
Normal: 3000psi
Max: 3500 psi
When will you get a REFILL indication for hydraulics?
76%
FLIGHT CONTROL switches
STBY RUD: activates standby pump and opens standby rudder shutoff valve to pressurize standby rudder power control unit
OFF: closes flight control shutoff valve isolating ailerons, elevators, and rudder from associated hydraulic system pressure
ON: (guarded postion) normal operating postion
Flight Control (LOW PRESSURE) lights
Illuminated:
Indicates low hydraulic system (A OR B) pressure to ailerons, elevator and rudder
deactivated when associated FLIGHT CONTROL switch is positioned to STBY RUD and standby rudder shutoff valve opens
STANDBY HYDRAULIC LOW QUANTITY light
Illuminated: Indicates low quantity in standby hydraulic reservoir
always armed
STANDBY HYDRAULIC LOW PRESSURE LIGHT Light
Illuminated:
- indicates output pressure of standby pump is low
- armed only when standby pump operation has been selected or automatic standby function is activated
ALTERNATE FLAPS master switch
OFF - normal operating position
ARM - closes trailing edge flap bypass valve, activates standby pump, and arms ALTERNATE FLAPS position switch
STBY RUD ON light
illuminated:
- indicates the standby hydraulic system is commanded on to pressurize the standby rudder power control unit
How many hydraulic systems?
A / B / standby
What does the hydraulic systems power?
Flight controls Leading edge flaps and slats Trailing edge flaps landing gear wheel brakes nose wheel steering thrust reversers autopilots
Can only A or B power all flight controls?
yes
System A and B are pressurized from the ?
Bleed Air
The standby system is pressurized from?
via the reservoir in system B
System A powers?
Ailerons rudder elevator flight spoilers (two on each wing) ground spoilers alternate brakes NO.1 thrust reverser Autopilot A normal nose wheel steering landing gear PTU main deck cargo
System B powers?
ailerons rudder elevator and elevator feel flight spoilers (two on each wing) leading edge flaps and slats trailing edge flaps normal brakes NO.2 thrust reverser Autopilot B alternate nose wheel steering landing gear transit unit autoslats yaw damper
How many pumps are in each system?
2: 1 engine pump and 1 AC electric motor driven pump
Min fuel for ground operation of electric motor-driven pumps is ?
1675lbs in the realted main tank
System A hydraulic leak associated with the engine driven pump leaves how much fluid left?
a standpipe prevents total system fluid loss.
with fluid at the top of the standpipe, the reservoir has about 20% fluid left
System B hydraulic leak will result in what?
A leak in either pump, line, or component of system will result in a decrease of quantity till 0 and the system b pressure is lost.
- There will remain enough fluid for PTU operation
- A leak in system B will not affect the operation of standby system
What is the purpose of the PTU
to supply additional volume of hydraulic fluid needed to operate the autoslats and leading edge flaps and slats at the normal rate when system B engine-driven hydraulic pump volume is lost.
