skyblue CBT Landing Gear and brakes Flashcards
what components make up each main gear?
2 wheels with tubeless tires and a hydro-pneumatic shock absorber
which hydraulic system powers the landing gear?
green
what is used to extedn the gear in the event of a hydraulic failure?
gravity gear extension
what does the gear position detection and indiaction system provide information to?
the crew and the MFC
what manages extension and retraction of landing gear?
MFC
what brakes are on each main gear?
2 sets of multi disk carbon brakes equipped with anti skid
what 3 things determine how much anti skid is delivered?
- wheel slip
- brake and tire wear
- runway conditions
what does the anti skid system deliver
touchdown protection
wheel lock protection
anti skid
when will the fusable plugs release tire pressure?
when temperature exceeds 177C
what does the pressure relief valve on the wheel do?
protects against overpressuriatstion
how are the multi disk carbon brakes operated?
hydraulically powered pistons
what is each carbon brake equipped with?
automatic adjuster
overheat detector
wear indicator pin
what is max deflection of the NWS?
60 degrees
which hydraulic system powers the NWS?
blue
when will we get a WHEELS BRK HOT on the EWD with a caution and chime?
when any brake temperature exceeds 150C
what are downlock and air ground signals provided by?
proximity sensors
what provides uplock signals?
mechanical limit switches
what is the primary detection and indication system controlled by?
MFC 1A
what is the primary detection and indication system powered by?
DC STBY BUS
what is the secondary detection and indication system controlled by?
MFC 2
what is the secondary detection and indication system powered by?
DC BUS 2
what does the WOW systems supply information to?
- pressurisation
- anti-ice systems
- other systems
what controls WOW system 1?
MFC 1B
what controls MFC system 2?
MFC 2B
what powers WOW system 1?
DC EMER BUS
what powers WOW system 2?
DC BUS 2
how is landing gear retracted?
MFC electrically controls a landing gear selectro valve in the main left gear fairing
the valve supplies green hydraulic pressure to unlock each gear
pressure is then delivered to the retraction side of the gear actuators
extension side of the actuators is then used to return hydraulic pressure to the resevoir
how are the nose gear doors driven?
mechanically
what happens when the gear is up?
- locked by an uplock mechanism
- hydraulic pressure removed from the retraction side of the actuator
how is the landing gear extended?
the MFC will supply green hydraulic pressure to retract the uplock mechanism
green hydraulic pressure is then provided to the extend side of the actuators
retract side is used to return fluid to the resevoir
what keeps the gear in the down position once extended?
dual alignment folding side brace and locking springs
what is the drag brace moitored for?
downlock indications
what happens to hydraulic pressure once gear is down and locked?
pressure removed from extension side of the actuator
what assists emergency gear extension on the main gear?
gas actuator and springs
what assists gear extension on the nose gear?
mechanical extension device
what locks gear in place when extended?
the braces
what powers the NWS?
blue hydraulic system
what powers the NWS selection valve?
DC EMER BUS
what can the NWS be deflected to in the abscense of blue hydraulic pressure?
91 degrees
what does the swivel valve do?
removes hydraulic pressure from the NWS when gear is not down
what does the solenoid valve do?
removes hydraulic pressure from the NWS when main gear shock absorbers are not compressed
this will also mechanically centre the nose gear
what is required for NWS?
all gear shock absorbers to be compressed
what happens to the NWS if one shock absorber is released during taxi?
NWS will still be avialble as long as one wheel is still on the ground
how is NWS controlled?
NWS switch on captains side. this arms the solenoid valve
what are the 2 brake operating modes?
normal mode
emergency and parking mode
how do braking modes provide pressure to the brakes?
shuttle valves
how much pressure is available for emergency braking?
500psi
when is additional pressure (more than 500psi) available for the emergency brake?
when below 60 knots
how much pressure is available to the park brake?
3000 psi
when should the tire be inspected?
if the hndle was used above 20GS to check the condition of the fusable plug
when is anti skid available?
gear down and locked at faster than 10 GS
what makes up the anti skid system?
- anti skid panel
- control box
- antiskid module
- 4x wheel speed transducers
what does the anti skid do?
calculates optimum decel and modulates pressure to the brakes to achieve correct tire speed.
what will anti skid system do if skidding is sensed?
reduce hydraulic pressure to the associated wheel
when will the anti skid system sense a locked wheel and release brake pressure?
speed differential in excess of 50% detected between inne and outer pair of main wheels
when is locked wheel protection available?
above 23GS
what powers inboard anti skid?
DC ESS BUS
what powers outboard anti skid?
DC EMER BUS
when will the touchdown protection prevent the brakes from operating?
- for 5 seconds after touchdown
- or as long as wheel speed is below 35 knots
when will the red gear handle light illuminate?
- flaps at 45 degrees
- flaps 30 degrees below 500RA
3 one power lever FI below 500RA
when will the red UNLK display?
gear not down and locked or
uplock box not in open position on the ground
up to what speed can we use the emergency brake?
V1
does anti skid operate when using the emergency brake?
no
where is the BRK TEMP test button?
F/O maintenance panel
how is a failed anti skid channel identified?
amber F in the EWD message during test or failure
when should the anti skid test not be carried out?
without parking brake set and engines running
when is anti skid test mode inhibited?
above 17GS
when will the park brake accumulator pressure display a failure?
when pressure below 1600psi
