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Flashcards in Hydraulics Deck (17):
1

How many Hydraulic systems are on the airplane?

-3 independent systems
-HYD 1, 2, and 3

2

What systems use Hydraulic power?

-Flight Controls
-Spoilers
-Landing Gear
-Nose wheel steering
-Wheel brakes
-Thrust Reversers

3

Can Hydraulic fluid be transferred between each system?

No

4

How many Hydraulic pumps are on the airplane?

6 Total
-2 EDP's (eng driven)
-4 ACMP's

5

What are the basic components of the hydraulic systems?

-Reservoir
-Pumps
-Accumulator

6

What is the purpose of the Accumulator?

-Helps maintain constant pressure by covering transient demands
-Helps to avoid pump cavitation

7

When will ACMP 1 or 2 automatically activate?

Ground
- Flaps > 0, and
-TL set to T/O, or
-Groundspeed > 50 knots
Flight
-Engine failure or EDP Failure
-Flaps > 0

8

What are some important items controlled by HYD 2 system?

Landing Gear
Nosewheel steering
Inboard Brakes

9

What is the PTU?

Power Transfer unit
Mechanical pump that uses HYD 1 power to provide HYD 2 pressure to assist with gear operation

10

What is the primary purpose of the PTU?

To allow landing gear retraction in the event of engine 2 or EDP 2 failure

11

When will the PTU automatically activate?

-During Takeoff and landing with Flaps > 0, if
- Engine 2 or EDP 2 Fails

12

How is single engine taxi possible if nose wheel steering is on HYD 2?

Releasing the parking brake activates ACMP 2

13

What is the primary purpose of HYD 3?

Back-up for flight controls

14

Why are HYD ACMP 3A & B pump switch positions ON & AUTO respectively?

-HYD ACMP 3A pump is primary and has no automation
-HYD ACMP 3B pump is back up and automatically activates if ACMP 3A fails

15

What, if any, HYD ACMP will function if the RAT is the only power source?

HYD ACMP 3A only

16

In an electrical emergency what provides hydraulic pressure to flight controls until the RAT comes online?

-HYD 3 Accumulator
-After 8 seconds the RAT will power ACMP 3A

17

In an electrical emergency can HYD 3 system power requirements overload the RAT?

No. a flow limiter valve is used to reduce flow and limits pump electrical power draw to prevent a RAT stall