Landing gear & Brakes Flashcards
Outboard Brakes
Outboard Brakes
Each main gear has both inboard and outboard brakes.
Hydraulic system 1 powers the outboard brakes.
Landing gear
Landing gear retraction and extension is powered by hydraulic system 2.
If EDP 2 (or engine 2) fails, the PTU assists in landing gear extension and retraction.
Onboard brakes and Nosewheel steering
Each main gear has both inboard and outboard brakes.
Hydraulic system 2 powers the inboard brakes and nosewheel steering.
Emergency/Parking Brake Accumulator
It stores hydraulic pressure from system 1 and 2 for the sole use of the Emergency/Parking Brake.
If hydraulic system 1 and 2 are depressurized, it provides enough pressure for 6 emergency/parking brake applications.
“Steer Off” displayed EICAS
STEER OFF displayed when steering is disconnected
• Hydraulic System 2 depressurized
•Steering disconnect switch is pressed (do not need to hold disconnect switch)on Yolk
•External Steering Disengage switch is set to DISENGAGE
Emergency Accumulator Pressure
The EMER ACCU PSI is shown on systems status page. If the indications are green, then there should be adequate pressure for the emer/parking brake to work
If indications are yellow (amber), the accumulator can be recharged by turning on the ACMPs in hydraulic system 1 and 2
Brake temperature Indication.
Found on systems status page. Both inboard and outboard brake temperatures must be in the green prior to takeoff
Auto Brake Selector Knob
RTO is a takeoff setting
LO/MED/HI are landing settings.
RTO (Rejected Takeoff) Setting
Automatically applies maximum braking during a rejected takeoff.
Recognizes a rejected takeoff by:
• Wheel speed above 60 kts, and
•Thrust levers in IDLE or REV (including MAX REV)
Releases the brakes when:
• Brake pedal pressure is applied (20%), or
•System faults (below 60 kts), or Thrust levers greater than IDLE
AutoBrake Lo setting
Automatically applies low braking on landing (gently applies brakes 2 seconds after weight on wheels).
Applies brakes to slows the airplane at about 2 knots per second (or 0.12 G’s).
Used for runway with adequate runway available
AutoBrake Med setting
Automatically applies medium braking on landing (applies brakes 2 seconds after weight on wheels).
Applies brakes to slows the airplane at about 4 knots per second (or 0.24 G’s)
-used on short or contaminated runways
AutoBrake Hi setting
Automatically applies high (not maximum) braking on landing (applies brakes 2 seconds after weight on wheels).
Applies brakes to slows the airplane at about 8 knots per second (or 0.41 G’s)
Rarely used do to aggressive and almost half g
When does Emergency/Parking Brake Light Illuminate?
ON is displayed when the emergency/parking brake is actuated and there is hydraulic pressure on the brake line.
DownLock release Button (Red)
The aircraft has WOW (Weight-on-wheels) sensors. When the WOW sense “on the ground”, the landing gear lever is mechanically locked in the down position.
Pressing the DN LOCK REL button overrides this protection and allows the landing gear lever to be moved regardless of the WOW sensors.
Landing Gear Lever
Commands normal extension and retraction of the landing gear (requires hydraulic pressure in system 2).