PC-21 Landing Gear Flashcards
How is the PC-21 landing gear powered and controlled/sequenced?
- Hydraulically powered
- Electrically controlled and sequenced
What does the Main Landing Gear (MLG) comprise of?
- MLG actuator
- Drag link
- MLG strut
- MLG door
- MLG uplock
- WOW sensor
- MLG up and locked proximity sensor
- MLG down and locked proximity sensor
What is the function of the MLG actuator?
Retract/extend main landing gear leg.
What are the functions of the drag link?
- Keeps main landing gear in the down and locked position
2. Pulls it into the wheel bay during retraction.
What is the function of the MLG strut?
Oleo-pneumatic shock struct that provides load absorption and shock dampening.
What does the WOW sensor do?
- Sends signals to various A/C systems
- Stops the landing gear being retracted whilst on the ground.
What are the main components of the Nose Landing Gear?
- NLG actuator
- NLG strut
- Drag link
- Spring pack strut
- 2 doors
- NLG down and locked proximity sensor
- NLG up and locked proximity sensor
- NLG uplock
- WOW sensor
What does the Landing Gear Control Unit (LGCU) provide?
- Indicates selected landing gear position
- Provides a gear position warning.
How is the EMRG LDG GR handle safety wired?
With a red cotton yarn which should always remain in place.
Once Landing gear handle has been pulled/pushed, describe th process that takes place?
- Electrical signal to extend/retract is initiated
- Main hydraulic system supplies pressurized hydraulic fluid to the 3 actuators, one for each landing gear leg
- Proximity sensor on each leg detected when the landing gear is in position and locked, signal is sent back to LGCU
- Hydraulic power disconnected from actuators 2 seconds after 3 landing gear are in position.
What is hte process when the EMER LDG GR handle is pulled?
- Emergency hydraulic system is activated which extends the landing gears
Where is the landing gear position indicated?
- Position lights on the LGCU
2. MFD HYD page under GEAR label
What do green inverted triangles on LGCU indicate?
Corresponding gear is down and locked
What do extinguished triangles and captions on LGCU indicate?
Gear is up
What do red UNLCK caption on the LGCU unit mean?
Gear is in transition.
What occurs if landing gear position sensors provide conflicting information?
Red and green illuminators are both illuminated on both LGCU and the MFD.
How are the LGCU’s powered?
From BATT BUS
What systems interact with WOW sensors?
- Air Data Computer
- MFD Maintenance
- Audio Management Unit
- Power Management System
- FMS Maintenance page
- Pitot static de-icing operation
7, Touchdown protection and spin up override - EMERGENCY BUS - the emergency battery is disconnected from the EMERGENCY BUS with weight on wheels to prevent the emergency battery
- UFCP control of the ATC transponder.
How can the pilot confirm that the landing gear is down and locked?
Pressing the DN TONE button on LGCU
What are the operating limits for the landing gear in transition?
- +2 g to 0 g
- 180 KIAS
With landing gear fully extended, what are the maneuvering limits?
+8 g to -4 g
180 KIAS
What does an amber GEAR caution on MFD indicate?
Landing gear does not reach its selected position within 20 seconds.
Under what conditions is an amber LANDING GEAR , Red light on landing gear handle and aural warning advisory generated on the MFD with a landing gear callout?
- Landing gear NOT selected DN and aircraft is on ground WOW
- Landing gear NOT selected DN, flaps selected to LDG and aircraft in descent
- Landing gear NOT selected DN, airspeed < 130 KIAS, PCL at position < 37 and aircraft < 5000 ft AGl
What can be done to cancel the alerts?
- Fix conditions to cause the alerts
2. Press the ALERT CANCEL button on LGCU
When is an amber OVERSPEED GEAR advisory displayed on the MFD ?
If the landing gear is not fully retracted and the airspeed is > 183 KIAS
When does an amber HARD LANDING advisory appear on MFD?
When aircraft rate of descent is > 600 ft/min on touchdown.
What does a grey WOW FAIL advisory on MFD?
If WOW malfunctions
