Landing Gear & Brakes Flashcards
When does the LANDING GEAR AWU kick in?
- RA<1200ft, flaps lower than 22 degrees and 1 TLA <59 degress + other TLA <49 degrees
- RA < 1200ft, flaps between 22 degress and 45 degrees, 1 TLA <59 degress + other TLA <49 degrees
- Flaps 45 degrees
What prevents the accidental raising of the landing gear on the ground
The LGEV solenoid
What does the LGEU control
The LGEV
What steering authority do you have via the rudder, tiller and both?
5 degress
71 degrees
76 degrees
What does a BRAKE DEGRADED message mean?
BCU not working or a total/partial loss of one inboard/outboard system.
How long does the parking brake last and how do we know it is still set?
24 hours. Pressure switch illuminates Brakes Set light.
How many applications of emergency braking do we get?
6
How many weight on wheels switches are there and where are they located
- 2 on each main gear and one on the nose wheel
What powers the LGEU
Essential DC bus
In what sense do the wheels retract?
Nose forward, main inward
What happens in normal gear extension?
Positioning the Landing Gear Lever to the DOWN position signals the LGEU to command the Landing Gear Electrovalve and the Nose Gear Doors Solenoid Valve. This allows pressure from the hydraulic system 1 to simultaneously reach the landing gear and door actuators, and also the up unlock actuators
How does the landing gear electrical override operate? From where?
This system bypasses the LGEU and actuates directly the Landing Gear Electrovalve and the Nose Gear Doors Solenoid Valve. The control switch is installed inside the free-fall lever compartment, on the floor, beside the copilot’s seat.
How does the free fall system operate? From where?
This system bypasses the LGEU and actuates directly the Landing Gear Electrovalve and the Nose Gear Doors Solenoid Valve. The control switch is installed inside the free-fall lever compartment, on the floor, beside the copilot’s seat.
When would you receive a LG/LEVER disagree warning and what does it mean?
20 seconds after a gear extension/retraction command and one of the wheels is not in the expected position.
When would you receive a LG AIR/GROUND fail
Where 2 proximity switches have failed, LGEU has failed or the NG switch disagrees with the AG logic
What does the Landing Gear Warning Cutout Button do?
Cancels the AWU if the rad alt is unserviceable and the LG is not down, flaps are lower than 22 and TLAs below 59/45
How are the brakes on the outboard wheels controlled
Hydraulic system 1, BCVs 1 and 4.
How are the brakes on the inboard wheels controlled
Hydraulic system 2, BCVs 2 and 3
How does the brake by wire system operate?
The BCU receives signals from the pedal transducers and commands the respective BCVs
What braking protection is offered by the 145?
Anti skid, locked wheel and touchdown.
Whats the technique for differential braking on this aircraft? Why?
Release pressure on the opposite wheel, because the anti skid system can only release brake pressure not apply it.
When does the anti skid system operate?
Above 10kts
When does the locked wheel system operate?
Speeds above 30kts with 30% difference in wheel speed
How does touchdown protection operate?
On landing it inhibits braking for 3 seconds or until wheel speed is 50kts.
If the WoW switches are malfunctioning normal braking will be available at 10kts wheel speed.
