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34 Cards in this Set

  • Front
  • Back
How many hydraulic systems are on the aircraft
3 independent systems

What systems use hydraulic power
Flight controls
Landing Gear
Nose Wheel Steering
Wheel Brakes
Thrust Reversers
Can hydraulic fluid be transferred between each system
How many hydraulic pumps are on the airplane
6 Total

2 engine driven
4 ACMP's
What are the basic components of the hydraulic system
What is the purpose of the accumulator
Helps to maintain a constant pressure

Helps to avoid pump cavitations
When will the ACMP 1 or 2 activate
Flaps >0 and TL set to T/O or GS >50 knots

-Engine failure or engine driven pump failure
-Flaps >0
What are some important items controlled by HYD SYST 2
Landing gear
Nose wheel steering
Inboard Brakes
What is the PTU
Power transfer unit

It is a mechanical pump that uses power from HYD SYST 1 and pressure from HYD SYST 2 to allow gear retraction and extension in the event of an engine 2 or engine driven 2 pump failure.
When will the PTU automatically activate
During takeoff or landing with flaps >0 if engine 2 or engine driven 2 pump fails
How is a single engine taxi possible if the nose wheel steering is on HYD SYST 2
By releasing the Emergency parking brake ACMP activates
What is the primary purpose of Hydrulic system 3
Backup system for the flight controls
Why are HYD SYST 3A and 3B ON and AUTO
3A is primary and has no automation

3B is a backup and automatically activates if 3A fails
What hydraulic ACMP will activate if the RAT is the only source of electrical power
Hydraulic ACMP 3A only
In an electrical emergency what provides hydraulic pressure to the flight controls until the RAT come online

After 8 seconds the RAT will power ACMP 3A
In an electrical emergency can HYD SYST 3 power requirements overload the RAT
No, a flow limiter valve and pump unloader valver are used to reduce flow and limit pump electrical power draw to prevent the rat from stalling
During a windmill start how is the enginge driven hydraulic pump affected
Pressure is reduced
How many PSI is the hydraulic system
3000 PSI
Where are the engine driven hydraulic pumps located
Accessory gear box of each engine
What hydraulic system is the emergency parking brake located on
1 and 2
Describe the PBIT tests
Upon power up the system will accomplish:
3 minute PBIT test to test electrics (Higher level functions, etc)

A 1 minute PBIT test will then occur to test the hydraulics
What is the normal and backup pumps for each system
System 1 and 2 primary is the engine driven pump and backup is the AC pumps.

System 3, 3A is the primary and 3B is the backup
What does the ON position do on the HYD systems pump knob do
Overrides the system logic and turns on the respective electric pump
What hydraulic fluid does the PTU use
System 2
When the RAT is deployed how does that affect flap operation
They operate at half speed
What systems use HYD system 1
G ground spoiler panel 2
E Elevator L outboard
T thrust reverser eng 1
M multifunction spoilers 3&4
O Outboard brake
R rudder upper actuator
E emergency parking brake
What systems use HYD system 2
G ground spoilers panel 1
I inboard brakes
M multifunction spoilers 5
E elevator L&R inboard
T thrust reverser engine 2
A aileron L&R inboard
L landing gear
N nosewheel steering
E emergency parking brake
What systems use HYD system 3
E elevator R outboard
A aileron L&R outboard
R rudder lower actuator
What would you expect the FADEC to do with HYD SYST 1 & 2 in the event of an engine flameout
It depressurizes the respective engine driven pump so as to facilitate engine windmill rpm (reduce torque for a restart)
Explain how the two dediated valves in hydraulic system 3 work during an electrical emergency
The pump unloader and flow limiter valves are both designed to reduce the amount of electricity used by HYD SYST 3 electric pump A so as to not stall the RAT
What provides hydraulic pressure from system 3 during an electrical emergency
Initially, the accumulator provides the pressure until the RAT is deployed and the AC ESS BUS is powered. At that time the system goes back to HYD SYST 3 ELEC pump 3A (B as a backup)
How many accumulators does each hydraulic system have
Hydraulic system 1 and 2=2
Hydraulic system 3=1
When will the PTU operate
During takeoff and landing with the selector knob in AUTO, flaps not set to 0,and if engine 2 or the engine driven hydraulic pump fails
During a single engine taxi releasing the emerg. parking brake will automatically activate what hydraulic pump
ACMP 2, allowing nose wheel steering and inboard brakes