Hydraulics Flashcards
The aircraft has how many hydraulic systems
3
What items on the aircraft use hydraulic power
1. Landing Gear 2 Flight Controls 3 Spoilers 4 Nose wheel stearind 5. Brakes 6 Thrust Reversers
Do the fluids mix between systems?
No
What type of fluid does it use and what PSI
3000 psi
Skydrol Hydraulic Fluid
What does the Engine Hydraulic Pump Shutoff Button Do
Closes the hydraulic shutoff valve. Isolating the EDP from the hydraulic system.
In flight when do the ACMP turn on?
- Engine Failure
2. Flaps greater than zero
On the ground when do the ACMP activate?
- Flaps greater than zero and
- thrust levers set to takeoff - 70 TLA
Or
- 50kts
What system is the Landing Gear and Nose Wheel starring on?
System 2. That’s why it had a Power transfer Unit
What temp do you get a Caution HYD 2 HI TEMP EICAS message
100 degrees
ACMP 2 will turn on on the ground when?
- Same items as EDP #1
2. Engine 1 running and parking break released.
What powers the PTU? And what is it’s purpose?
Mechanically driven by hydraulic system 1. No Electricity.
Connected to system 2 to aid in Gear retraction or extension, and aid in case the EDP 2 fails or Engine 2 fails
When does the PTU activate
It activates only in the air. When all these conditions are met.
- EDP 1 is working
- Flaps greater than zero or Gear not up and locked
- Reservoir 2 is greater than 12%
- Engine 2 and or EDP fails
When does ACMP 3B turn on
- If ACMP 3A fails
2. If selected to ON. Than it runs continuously
During an electrical failure what powers the flight controls while the RAT comes out?
The accumulator.
What ACMP does the RAT power?
3A via the AC ESS BUS
Why is single engine taxi done on Eng 1
Because when Engine 1 is on. ACMP 2 turns on when parking brake is off powering inboard brakes and Nose wheel steering.
What is the purpose of the PTU
To back up EDP 2
At what reservoir temperature must you do a Hydraulic System Warm-up
-18C
What will interrupt the Hydraulic PBIT?
Movement of the flight controls.
“FLT CTRL TEST IN PROG” message will appear after starting engine #1 and after the parking brake is released. What does it indicate?
The Hydraulic Porting of the Flight Control check is in progress.
What engine should you start first?
Engine #1. Hydraulic ACMP 2 will automatically come on with the left engine running, the parking brake off, and the knob in AUTO.
Can we depart with AMBER brake Temp indications?
NO
The emergency parking brake has its own accumulators that will give you how many brake applications with both system 1 and 2 de-pressurize?
6 applications
If hydraulic pump 3A fails on the ground, will it turn on 3B automatically?
No 3B will only turn on automatically in the air.
Why is Hydraulic Pump 3A have ON or OFF
Because we want to make sure that if the RAT power 3A with no interruption.
What systems are on Hydraulic System 2 that is important?
- Inboards Brakes
- Landing Gear
- Nose Wheel Steering
When Will Hydraulic Pump 2A turn on, on the ground for taxi?
- Engine 1 is running
- Realized Parking Brake
- The Pump stays on for 6 minutes after the brake is set.
Why do we have a PTU
EDP -> 19 gal/m - 3000psi
ACMP 2 -> 3.7 gal/m - 3000psi
The ACMP 2 does not retract or extend the gear fast enough so the PTU is there to provide more flow rate in system 2.
When does the PTU Turn on
- Flaps greater than zero OR
2. Gear not up and locked
What temperature does the Warning HYD 1 OVERHEAT
145 C Degrees
What temperature does the Engine Hydraulic shutoff valve close?
125 C Degrees
