Landing Gear, Brakes Flashcards
Which hydraulics normally powers the landing gear?
Green hydraulics
Which system extends and retracts the landing gear?
The green hydraulic system
When do the LGCIU 1 & 2 switch?
After each retraction of the landing gears
When is the green hydraulic pressure removed from the landing gear?
When the speed is 260kts or when the gears are in the up position, the safety valve is closed
Which computer controls the nose wheel steering?
BSCU Brake & Steering Control Unit
What are the 4 braking systems?
- Normal (BSCU) - uses the green hydraulics
- Alternate (ABCU), with antiskid (BSCU) - uses the yellow hydraulics, nose wheel and anti skid is on
- Alternate (ABCU) without antiskid - uses the yellow hydraulics
- Accumulator Braking (7 applications of the brakes limit) - loss of both green & yellow hydraulics, nose wheel and anti skid is switched off
Turning of the nosewheel and anti skid does what?
The brake system switches from green to yellow hydraulics
The Autobrakes use which hydraulic?
The green
The brake arcs on ECAM when which temps?
Green when the temp is greater than 100degC or amber if greater than 300degC
When do the Accumulator braking activate on the braking system?
What happens then?
What is the call out for the PM?
When both the green and yellow hydraulics are lost and the pilots shut off: the Nose Wheel and Anti Skid lever.
We get 7 braking applications with no anti skid
1,000 left/right call out
Why was anti skid not included in the Accumulator Braking?
Because it would rapidly diminish the Accu Pressure
What is the difference between the BSCU and ABCU?
How do they work together in the event of loss of braking.
When does the Accumulator Braking come on?
Normal brakes, auto brakes, anti skid, brake temperature are controlled by the BSCU. Brake Steering Control Unit.
Alternate brakes are with the ABCU. Alternate Brake Control Unit
If normal braking is lost, ABCU takes over the alternate brake but the anti skid and brake temperature are still taken from the BSCU. No auto brakes. This is NOT the Accumulator Braking of 7 applications.
If we lose the Yellow system, then the Accumulator Braking comes on line. Using 7 applications of braking only.
How many channels does the BSCU have?
2
Is auto brake available when using alternate braking?
No. Only manual is available
With the loss of the green hydraulics, how do we transfer to the alternate brakes with antiskid?
It is automatic
When the nose wheel and anti skid switched off, how do we control the direction of the aircraft
Through minimal braking and rudder inputs
After touchdown, when is anti skid normally deactivated?
Ground speed is less than 20 kts
Can the auto brakes be armed wit the parking brakes on?
Yes
Minimum ground spoiler speed for auto brakes to activate on the take off?
72 kts
What percent does DECEL need on the auto brakes to illuminate? When can it fail to illuminate?
80%.
It can fail to illuminate on slippery surfaces. The system is not failed. But the rate of 80% deceleration has not been achieved.
How many seconds will it take before the auto brakes activate for Lo and Med after touchdown?
If ground spoilers are armed, 4 seconds from gears compressed or if not armed, after 1 reverser is set.
2 seconds for medium
4 ways to disarm the auto brakes after landing?
- Pressing the auto brake pb
- Arming condition is lost
- Pressing on the brakes
- Disarming the ground spoilers
When do the auto brakes disarm after take off?
10 seconds after take off
How long can accumulator pressure maintain the park brakes?
12 hours
How can the Accumulator Pressure be repressurized back to the green band?
Turning on the Yellow Electric Pump switch on the overhead panel
