Hydraulic System Flashcards
How many hydraulic systems are there on the 737?
3 total: A, B, and Standby.
Which engines have hydraulic pumps?
Engines 1 and 2.
How many and what type of pumps does the A hydraulic system use?
2 hydraulic pumps, 1 engine, and 1 electrical.
How many and what type of pumps does the B hydraulic system use?
2 hydraulic pumps, 1 engine, and 1 electrical.
How many and what type of pumps does the Standby hydraulic system use?
1 electric pump.
What equipment is on the A hydraulic system?
- Ailerons
- Landing Gear
- Elevators
- Alternate (Manual) Brakes
- Rudders
- Nose Wheel Steering
- Inboard Flight Spoilers
- Number 1 Thrust Reverser
- Ground Spoilers
What equipment is on the B hydraulic system?
- Yaw Dampers
- Elevators
- Ailerons
- Rudder
- Outboard Spoilers
- Flaps
- Brakes
- Autoslats
- LEDs (Leading Edge Devices)
- Landing Gear (retract only)
- Alternate Nose Wheel Steering
- Number 2 Thrust Reverser
What equipment is on the Standby hydraulic system?
- Rudders
- LEDs
- Standby Yaw Damper
- Number 1 and 2 Thrust Reverser (very weak)
Is there a backup to nose-wheel steering?
Yes, the main is on system A and an alternate is on system B.
If the A hydraulic system is lost, how can the landing gear be lowered on the 737?
The landing gear can be cranked up until the locking mechanism releases, allowing the landing gear to free fall into a down and locked position.
If the A hydraulic system is lost, how can the landing gear be raised?
The B hydraulic system is capable of retracting the landing gear.
If the A hydraulic system is lost, is there a backup for the Ailerons and Elevators?
Yes, on the B hydraulic system.
If both the A and B hydraulic systems are lost, is there a backup for the Ailerons and Rudders?
Yes, it is called manual reversion.
What is manual reversion?
A backup system for the flight controls that allows the pilot to control the plane using physical effort via a system of wire cables and pulleys.
If hydraulic system B fails, is there a backup for the flaps?
Yes, electric flaps.
If hydraulic system B fails, is there a backup for the LEDs?
Yes, on the standby system.
Do spoilers have a backup on the 737?
No, there are no backups for the spoilers.
Is there a backup for the Rudder if the A hydraulic system fails?
Yes, the rudders can be operated by all three systems.
Which system supplies hydraulic power to the brakes?
The B system.
If the B hydraulic system is lost, is there a backup for the brakes?
Yes, there are 2 backups for the brakes: Brake Interconnect and Brake Accumulator Bottle.
What is the normal operating pressure for the hydraulic systems?
3,000 psi (pounds per square inch).
If you lose hydraulic pressure, is it considered an emergency?
Yes.
What is the most common case of a hydraulic system failure?
A leak in the reservoir or a ruptured hydraulic line.
