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Flashcards in Hydraulics Deck (59)
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1
Q

What happens if centre hydraulic system quantity is sensed low?

A
  • Centre 1 elec pump is automatically isolated to provide hydraulic pressure to the RESERVE BRAKES & STEERING
  • The ISLN light for C HYD SYS on the rear panel illuminates
2
Q

What systems power the Flight controls?

A
  • All 3
3
Q

What does the RAT do?

A
  • Provides hydraulic pressure to the flight controls portion of the Centre Hydraulic System
  • Provides adequate hydraulic power for flight controls at speeds above 130kt
  • Deploys automatically when both engines fail (Engines drop BLW idle)
  • Cannot be stowed in flight
  • In right wheel well
4
Q

What does the Pitch enhancement system do and when does it activate?

A
  • Auto activates if the Left & Centre HYD systems fail and trim switches are used
  • A pump in the right system uses trapped left system fluid to operate the stabilizer
  • Elec trim is available at approx 1/4th of the rate
  • Alternate and auto trim inop
5
Q

What systems have reservoirs? Are they pressurised?

A
  • Each system has own reservoir
  • PRESSURIZED from bleed air
6
Q

How is the centre hydraulic system demand pump powered?

A
  • By the Pneumatic system
7
Q

Does the centre Air Demand pump ever Auto operate?

A
  • Yes when there is a large demand on the centre system such as when operating the landing gear, flaps/slats and ground spoilers
  • Pump also operates whenever system pressure is low
  • Air supply valve opens and pump operates to provide additional system pressure
8
Q

What Hydraulic pump is load shed and when?

A
  • The C2 pump
  • Load shed when on GND and only one source of electrical power
  • APU, EXT PWR or 1 ENG GEN
9
Q

Does an autopilot become inop when the left hydraulic system fails?

A
  • Yes the Left autopilot
10
Q

When will an RF appear on the hydraulic system quantity?

A
  • Below 0.75
11
Q

When does the QTY light illuminate on the overhead panel and what other indication do you get with this?

A
  • Below .48
  • Also illuminates HYD QUANTITY EICAS advisory message
12
Q

When does the RAT deploy automatically?

A
  • When both engines fail in flight (both sensed below idle)
  • Provides adequate power for operation of the flight controls portion of the centre hydraulic system at airspeeds ABV 130kts
13
Q

When does the tail skid extend and retract and what powers it?

A
  • Extends and retracts with LDG gear
  • Powered by the Centre HYD system
14
Q

Using Alternate Gear extension does the tailskid extend?

A
  • No
15
Q

When do the gear doors stay open?

A
  • If there is no pressure in the centre hydraulic system after an Alternate gear extension
  • GEAR DOORS displays on EICAS
16
Q

Is anti skid available in the alternate brake system?

A
  • Yes provided in normal and alternate systems
  • NORMAL - Each making gear wheel is provided with individual anti skid protection
  • ALTERNATE - Provided to laterally paired wheels
17
Q

How are the nose and main gear held in the up and locked position?

A
  • Nose gear - up locks
  • Main Gear - door structure
18
Q

What does the green PRESS light on the RAT panel indicate?

A
  • RAT is deployed and RAT is producing hydraulic pressure
19
Q

When does Auto braking application commence on touchdown?

A
  • Both thrust levers retarded to idle
  • Wheels have spun up
  • Nose attitude is less then 1 degree
20
Q

What does touchdown protection provide?

A
  • Ensures rear wheel brakes do not have hydraulic pressure at touchdown
21
Q

How does the braking system provide hydro planning protection?

A
  • Compares IRS ground speed to wheel speed and decreases aft wheel brake pressure when ground speed is greater then wheel speed
22
Q

How does the braking system provide locked wheel protection?

A
  • Compares the speed of each fore and aft wheel pair
  • Releases hydraulic pressure from the slower wheel when the speed difference is greater than 25kts
23
Q

What powers the Elevators?

A
  • Right, Center & Left systems
  • Can still power if 2 systems lost
24
Q

Does Autopilot trim at the same rate as electric or manual?

A
  • No it trim as at one half the rate as it has only one trim control module
25
Q

When are the Electric trim switches inhibited?

A
  • During auto-land or Go-around with multiple autopilots engaged
26
Q

What are the 2 types of unsched stab trim?

A
  • Stabilizer moves without a trim signal
  • Stabilizer movement is opposite the direction signalled
27
Q

What do the STAB TRIM CUTOUT switches do when in NORM & CUTOUT?

A
  • NORM - keeps hydraulic supply shutoff open
  • CUTOUT- shuts off respective Center or Left hydraulic system power to the related stab trim control module
28
Q

What powers the rudder? Can it still operate if two systems are lost?

A
  • Pedals control 3 hydraulic actuators that move the rudder
  • Each system powers one
  • Can still operate if two systems lost but displacement limited
29
Q

What does the Rudder ratio changer do?

A
  • Uses airspeed information to vary the amount of rudder displacement providing structural protection for the rudder
  • LOW SPEEDS = Full displacement
  • HIGH SPEEDS = Limited displacement
  • Powered by the LEFT hydraulic system
30
Q

What happens if there is a rudder ratio changer fault?

A
  • Left HYD system automatically rudder actuator automatically depressurises to provide structural protection for the rudder
  • RUDDER RATIO - EICAS message displays
31
Q

What does the failure of a one Yaw Damper do?

A
  • Reduces the total yaw damping authority by one half
32
Q

What does no white band indicate on the stab trim indicator?

A
  • Stab trim indicator malfunctions other than power failure
33
Q

How many ailerons are there?

A
  • 2 each wing- inboard and outboard
34
Q

How many spoilers are there?

A
  • 12
  • 6 each wing
  • 2 x inboard
  • 4 x outboard
35
Q

What system powers the ailerons? How many to have aileron control?

A
  • All three power them
  • If one or two systems are lost you still have aileron control
36
Q

What do the ailerons do with flap extension?

A
  • The inboards droop in conjunction with trailing edge flap extension
37
Q

When if ever are spoilers inhibited from responding to control wheel commands?

A
  • At cruise speed
  • Two spoilers on each wing are inhibited this prevents over controlling
38
Q

Are ailerons ever locked out?

A
  • Yes at high speeds
  • Prevents operation of outboard ailerons to protect against over controlling
39
Q

How many spoilers are used with the the Speedbrake lever inflight?

A
  • All but 2 are used
  • 4 & 9 (3rd from the fuselage, the first outboard)
  • Should not be used with flap greater than 5 to avoid buffeting
40
Q

When will the speedbrakes extend if in the armed position?

A
  • Thrust levers idle
  • HYD pressure to gear tilt actuators
  • Sensors detect airplane on the ground
41
Q

When do the speedbrakes automatically retract?

A
  • When thrust levers are moved from idle on ground
42
Q

When does the SPEEDBRAKES EXT and Caution appear?

A
  • Speedbrakes extended when RAD ALT is 800ft or below or:
  • Flaps are in landing position
43
Q

How are the flaps and slats powered in the Normal and Alternate operation?

A
  • NORMAL - Hydraulic powered
  • ALTERNATE - Electric
44
Q

How many slats are there?

A
  • 10 outboard (5 a wing)
  • 2 inboard (1 a wing)
  • Center HYD system powers through 3 separate power drive units
45
Q

What happens when flaps are moved to position 1?

A
  • Just the slats extend to takeoff position
46
Q

What happens with flaps 5, 15 & 20?

A
  • Slats remain in takeoff position
  • Flaps extend to required position
  • Inboard ailerons droop in conjunction with flap extension
47
Q

What happens at Flaps 25 & 30?

A
  • Slats extend to their landing position
  • Flaps extend to selected position
  • Inboard ailerons droop
48
Q

When does the flap load relief system arm and what does it do?

A
  • Arms at flaps 25 or 30
  • Retracts flaps position to 20
  • Prevents flap extension to position 25 and 30
  • Automatically reselects flap after speed is ok
  • Slats remain in LDG config
49
Q

How does the ALTN FLAPS work and what has priority?

A
  • Driven by electric motor
  • Overrides flap lever control inputs
50
Q

How long does the ALTN system take to extend to Flaps 20?

A
  • 3 minutes
51
Q

Do you still have Flap Load relief protection during ALTN flaps selector?

A
  • No flap load relief in alternate
52
Q

Does the ALTN slat switch provide asymmetry protection?

A
  • No slat assymetry protection provided
53
Q

What system powers the spoilers?

A

Long range cruise cuts costs lots - for Left wing??

Long range cruise cuts costs right - for right wing??

54
Q

When is the alternate brake system pressurized and from where?

A
  • When right side pressure is low
  • The center system automatically supplies pressure to the alternate system
55
Q

What does the Center hydraulic system power in regards to the LDG gear?

A
  • Retraction, extension & steering
  • Alternate brake system
56
Q

What brake system are autobrakes provided with?

A
  • Only normal system not alternate
57
Q

How many power sources does each hydraulic system have?

A

Left and Right have 2 sources:

  • 1 engine driven pump
  • 1 AC pump which operates on demand

Center has 4 sources:

  • 2 AC pumps
  • 1 Air Driven Pump which operates on demand
  • 1 RAT
58
Q

Rudder ratio changer powered by?

A
  • Left system only and has only one actuator
59
Q

Why do you depressurize the right HYD system last?

A
  • C & R systems share a part of the brake lines
  • If R system is turned off prior to C system the brake source is changed to the C system and fluid transfer from R to C system occurs