Lesson 10: RETRACTION & MAINTENANCE Flashcards
What do small aircrafts use to activate L/G retraction?
Hydraulic Power Pack
What happens when the flight deck L/G lever is selected up on a small aircraft?
Hydraulic pump sends fluid to RETRACT side of actuator thus releasing DOWN LOCKS and gear retracts
What does a PRESSURE SWITCH do?
Stops the pump when the landing gear is fully retracted
If there are no mechanical up locks, how are the L/G kept retracted?
Trapped hyd line psi
If the hyd psi drops to a pre-determined psi, what will happen?
L/G drops, opens LIMIT SWITCH, hyd pump automatically restores system psi
When will fluid flow to the EXTEND side of the actuators?
L/G lever selected to DOWN position
If the primary system should fail, what do we do?
EMERGENCY L/G release
This component will operate to port fluid to the reservoir from BOTH side of the L/G actuators
FREE FALL VALVE
If the EMERGENCY FREE FALL VALVE is operating AUTO, how does it work?
L/G extended at LOW AIRSPEED in flight, pitot/static psi sensed
What are the ways AMPHIBIOUS floats can be actuated?
Mechanically
Hydraulically
What is the difference between small and large aircraft L/G extension/retraction systems?
Large has more components such as:
- Wheel well doors
- Mechanical up/down lock
- door/gear sequencing
- hydraulic restrictor
How are LARGE aircraft L/G systems controlled and actuated?
Mechanically/Electrically controlled
Hydraulically actuated
This component prevents gear retraction unless the aircraft is in flight mode
Baulk
How do door UP LOCKS function?
Mechanically latched
Hydraulically released
When EXTENDING L/G what happens?
- Retraction actuator RETRACTS to EXTEND L/G
2. Down Lock actuator locks in OVER CENTRE position preventing the SIDE STAY from folding
When RETRACTING the L/G what happens?
- Down Lock actuator BREAKS the over centre of the lock stay
- Retraction actuator EXTENDS to RETRACT the gear, folding the side strut
What are the different methods of Emergency Extensions in large aircraft?
Mechanical
Alternate hydraulic
Compressed Air
Free Fall
During L/G maintenance what should you do?
L/G should be locked out with DOWN LOCK PIN and ACTUATOR LOCKOUT COLLAR
What else should be tagged and locked?
DOOR lockout
What is RIGGING?
Correct ALIGNMENT and ADJUSTMENTS of all L/G parts
When do we do retraction checks on small aircraft?
Every 100hrs
Annual Inspection
When do we do retraction checks on large aircrafts?
Letter checks
In general why would we do retraction checks?
Critical gear component replaced
Rigging req.
Troubleshooting
