Landing Gear & Brakes Flashcards
What provides pressure to the Outboard Brakes?
Hydraulic System 1
What provides pressure to the Inboard Brakes?
Hydraulic System 2
How is Brake Wear detected?
By Brake Wear Pins located on each main wheel
What indicates that the brakes need replacement?
When the Brake Wear Pins are flush with the Brake Bracket Outer Face Assembly
What does a Brake Wear Pin flush with the Brake Bracket Outer Face Assembly Indicate?
The Brakes need Replacing
What is a Fusible Plug?
They are attached to the wheels, and melt to relieve tyre pressure in the event of a tyre overheat
What are the 4 Protections provided by the Brake System?
Antiskid
Touchdown
Locked Wheel
Automatic Wheel Braking
What is Locked Wheel Protection?
Maximises brake efficiency in the event of a wheel lock, by relieving hydraulic pressure
When does Locked Wheel Protection become active?
ON GROUND
Wheel Speed above 30kts
What is Touchdown Protection?
It prevents the aircraft from touching down with the main wheel brakes applied
When is Touchdown Protection deactivated?
3 seconds after WOW - ON GROUND
OR
Wheel Speed above 50kts
What is Antiskid Protection?
Prevents the tyres skidding and maximises brake efficiency for the runway surface
How does Antiskid Protection work?
It controls the hydraulic pressure applied to the brakes, if necessary reducing the pressure to recover wheel speed and prevent skidding
When is Antiskid Protection activated?
Wheel Speed above 10kts
Below what speed is Antiskid Protection deactivated?
Wheel Speed below 10kts
Why is the Antiskid Protection deactivated below 10kts?
To allow for lock and pivot on a wheel when manoeuvring/parking
What is Automatic Wheel Braking?
It prevents the MAIN gear from being retracted with wheels spinning
What Protections do the Main Wheel Brakes have?
Antiskid
Touchdown
Automatic Wheel Braking
Locked Wheel
What Protections does the Autobrake have?
Antiskid
Touchdown
Locked Wheel
What must be operational to arm the Autobrake?
The Normal Braking System
What are the 4 Autobrake Modes?
LO, MED, HI, RTO
When will the Autobrake be ARMED in RTO mode?
RTO set
ON GROUND
Below 60kts
No Faults
Thrust Levers IDLE or REV
Brake Position: Any
When will the Autobrake be ARMED in LO, MED or HI Landing Mode?
LO, MED, HI set
IN FLIGHT
Below 60kts
No Faults
Brakes not pressed
Thrust Lever Position: Any
When will the Autobrake be ACTIVATED in RTO mode?
ARMED
RTO
ON GROUND
Above 60kts
No faults
Brakes not pressed
Thrust Levers: IDLE or REV
When will the Autobrake be ACTIVATED in LO, MED or HI Landing mode?
ARMED
LO, MED, HI set
ON GROUND (WOW for more than 2 seconds)
Above 60kts
No faults
Brakes not pressed
Thrust Levers: IDLE or REV
When will the Autobrake be DEACTIVATED in RTO mode?
Any mode other than RTO set
IN FLIGHT
Faults detected at speeds below 60kts
Brakes pressed while Autobrake is being applied
Thrust levers above idle when Autobrake is being applied
When will the Autobrake be DEACTIVATED in LO, MED or HI Landing Mode?
OFF or RTO set
Faults Detected
Brakes applied (more than 20%)
Thrust levers above idle when Autobrake is being applied
What Hydraulic Systems operate the Emer/Parking Brake?
Hydraulic Systems 1 & 2
How many Full Brake Applications does the Emergency Brake Accumulator Provide?
6
Does the Emer/Parking Brake have Anti-Skid Protection?
No
How would the aircraft stop in the event of a simultaneous failure of both hydraulic systems/failure of both brake control modules?
The Emer/Parking Brake has the ability to stop the aircraft, as it has pressure accumulators separate from both Hydraulic Systems
How are the brakes controlled?
Control Modules
2 x BCM (Brake Control Modules)
1 x ABM (Autobrake Control Module)
To what are the BCMs connected and what do they control?
BCM 1 - DC ESS BUS 1, Outboard Brakes
BCM 2 - DC ESS BUS 2, Inboard brakes
ABM - DC Bus 2, Autobrake
What controls and powers the Nose Wheel Steering?
Electronically Controlled by Nose Wheel Steering Control Module
Powered by Hydraulic System 2
What are the 3 modes for operating the Nose Wheel Steering System?
Handwheel Steering
Rudder Pedal Steering
Free Wheel Steering