Landing Gear Flashcards
Vlo/Vle
270 / .78M whichever is less. (ALTN 250/.75)
When is the Landing Gear inhibited from retraction?
- On the Ground.
- Tilt Issue.
How is the LG Powered?
Extension, Retraction, Steering - Center Hydraulic System.
Normal/Auto Brakes - R HYD.
ALT Brakes - C HYD.
Anti-Skid - R or C HYD
What uses Nose Air / Ground Sensing Signals?
- Stall Warning System inhibits
- Master Caution and Warning Inhibits
AIR/GND SYS light
NOSE A/G SYS light
- No Takeoff.
- FAULT. Some portion of the A/G Sensing System has failed, and affected systems will not function properly.
What holds the LG up?
- Nose - HYD PRESS.
- Main Gear - Doors.
What happens if LG does not retract?
- GEAR Light will indicate immediately.
- EICAS and Horn are delayed 25 second for transit.
- DOOR Light will remain illuminated.
- Gear Down Light will remain illuminated if appropriate.
Describe Extension.
- Lever in Down Position.
- GEAR and DOOR Lights illuminate.
- Hydraulically actuated DOWN.
- Hydraulically closed doors.
- Lights go out.
How will you know if the LG is not down and locked?
- Extinguished Green gear down light.
- Illuminated Amber GEAR light.
- EICAS messages.
Describe an alternate extension.
- Electric motor trips locking mechanism for each gear.
- Seleting DN on the ALTN GEAR EXTEND switch releases all unlocks and doors.
- Gravity to down and locked.
- DOORS remain open, and lights remain ON.
How much steering authority do you have?
- 65 Degrees L or R with the Tiller, 7 with the peddles.
What does the break system include?
- Normal Brake Hydraulic System. (R HYD Sys.)
- Alternate Brake Hydraulic System. (C HYD Sys.)
- Brake Accumulator.
- Antiskid.
- Autobrake.
- Parking Brake.
When does the Alternate Brake System Activate?
- Automatically, when the R HYD System Pressure is low.
What does Normal Braking include?
- Autobrakes.
- Wheel for wheel antiskid.
What does the Brake Pressure Dial measure?
- Accumulator pressure, and indirectly, R HYD System and Normal Brake Pressure.
- Should be above amber.
- Should allow for several brake applications.
What does the Alternate Brake System include?
- Alternate Metering Valves.
- Alternate antiskid valves (axel for axel).
- No Autobrake.
How does antiskid work?
Controllers compare wheel/axel speed in relation to IRS GS, and release pressure into a relief line, as appropriate.
Describe Autobrakes.
- Normal is 2.
- If Autoland, 3 or more.
- If Braking action less than good, 4 or Max.
- System is designed to produce a RATE OF DECELERATION.
- Deactivates when Manual Brake force is applied, Selected OFF, Thrust applied, or for a FAULT. (Speedbrakes?)
What are the relative application of braking actions by different systems?
- RTO - full application of all 3000 psi.
- MAX Auto is pretty stiff.
- Max Manual depends, but definitely less than RTO.
When will a BRK SOURCE light illuminate? What Happens?
- R HYD and ALTN Brakes (C HYD Low Press) FAIL.
- ISLN Valve Automatically Closes.
- Press RSRV BRK and STEERING provides fluid and activates the C1 HYD Pump.
- BRAKE SOURCE Light should extinguish.
- If not, you’re down to the accumulator (still has antiskid)
When is RTO Armed?
Above 85 kts. (Automatic when thrust levers are retarded to Idle above 85 kts.)
Describe Autobrake Landing Operation.
- Activates when the wheels have spun up and both thrust levers are retarded to idle.
- 5 deceleration rates.
- Autobrake level can be changed without disarming the system.
- Autobrake pressure reduced to maintain chosen rate when/if other systems (reversers and spoilers) are deployed.
Auto brake disarm.
- Manual Pedal brake application.
- Either thrust lever advanced.
- Spoiler lever moved from full up position.
- Selected OFF/Disarm.
- Autobrake Fault.
- Antiskid Fault.
