737 Hydraulics Flashcards
Explain meaning of a hydraulic amber LOW PRESSURE indication.
Out put pressure of the associated pump is low.
What is the meaning of an amber hydraulic OVERHEAT light?
Where else will the overheat be indicated?
hydraulic fluid used to cool and lubricate the corresponding electric motor driven pump has overheated or the pump itself has overheated.
On the FO side master caution light and recall panel.
Where is the hydraulic fluid quantity displayed and how does the crew know if the quantity is low?
How is Low quantity in the Standby Hydraulic System determined?
Quantities for the A and B systems are displayed on the lower DU by pushing the MFD system (SYS) Switch. A white refill (RF) beside the quantity indicates low Hydro fluid.
By the LOW QUANTITY light on the overhead Forward overhead panel.
What is the function of the ENGINE HYDRAULIC PUMP Switches?
ON - Denergizes the blocking valve (not the engine driven pump itself) to allow pump pressure to enter system.
OFF - Energizes the blocking valve to block pump output
NOTE: Normally these remain ON at shutdown to prolong solenoid life.
How many hydraulic systems are on the B737?
3 - two mains (A and B) and one standby system.
What do the ELECTRIC HYDRAULIC PUMP switches do?
ON - provides power to the electric motor-driven pump.
What does the standby hydraulic system power?
- Rudder
- Leading edge flaps and slats and auto slats
- Thrust Reverser
- Yaw Damper
How is the standby hydraulic system refilled it is is low?
How low does the standby fluid have to get before a LOW QUANTITY indication shows up on the flight controls panel?
Through System B Reservoir.
50%.
When is the RF (refill) indication for the hydraulic system accurate or valid?
Only on the ground with both engines shut down or after landing with the flaps retracted.
What is the maximum and minimum allowable pressure of the hydraulic systems?
3500 psi max, 2800 psi min, 3000 is normal.
