Landing Gear & Brakes Flashcards
What type of landing gear is used?
Hydraulically actuated, electrically powered, retractable, tricycle landing gear with a steerable nose gear
The design allows for enhanced maneuverability and stability during ground operations.
What type of shock absorber is used in each gear?
Nitrogen-oil shock absorber
This design helps in absorbing the forces experienced during landing.
What design feature does the main gear have to absorb landing forces?
Trailing link design
This design helps to effectively manage the impact forces during landing.
What is the normal strut extension for the main gear?
2 inches
This extension contributes to the overall landing gear functionality.
What is the normal strut extension for the nose gear?
4.25 inches
This extension helps maintain stability and control during landing.
How is ground steering achieved?
With rudder pedals in combination with differential braking and/or differential power
This method allows for precise maneuvering on the ground.
What is the purpose of the nose gear rake angle?
To prevent nose wheel shimmy
This design feature enhances the safety and stability of the aircraft during landing and takeoff.
What type of hydraulic fluid is used?
MIL-H5606 (Red) hydraulic fluid
This fluid is commonly used in aviation hydraulic systems for its performance characteristics.
What does the LANDING GEAR selector indicate when the gear is down-and-locked?
Green lights illuminate
This visual indicator helps the pilot confirm the landing gear position.
What does the red unsafe light indicate?
Gear is neither fully retracted nor down-and-locked
This alert is crucial for ensuring safe operations before landing.
What is the function of the GEAR/FIRE TEST switch?
It activates the electrically-actuated hydraulic pump
This is important for testing the hydraulic system associated with the landing gear.
What components are included in the hydraulic system?
- Hydraulic reservoir
- Hydraulic pressure accumulator
- Electrically-controlled extend and retract hydraulic valves
- Manual emergency gear extension valve
These components work together to control the landing gear operation.
Where are the pump, accumulator, and solenoid-actuated hydraulic valves located?
Behind rear baggage compartment
This location helps in optimizing space and weight distribution.
What detects the position of each landing gear?
Micro switches
These switches provide critical feedback to the landing gear system.
What do squat switches detect?
When the aircraft is on the ground
This detection is important for operational safety and system functionality.
What happens to each landing gear actuator when the gear is extended?
Each landing gear actuator becomes shorter to extend the gear into the down-and-locked position.
When is the hydraulic system pressurized?
Whenever ELECT MASTER is ON and electric power is available.
What holds the landing gear in the down-and-locked position?
Hydraulic pressure in combination with a locking hook on each gear.
What is the charge pressure of the nitrogen-pressurized hydraulic accumulator?
1150 PSI.
What are the functions of the nitrogen-pressurized hydraulic accumulator?
- Helps maintain constant hydraulic pressure
- Reduces the amount of time the gear pump is active during flight
- Dampens pressure changes that occur during normal operation.
What should you verify before extending the landing gear?
Verify the LANDING GEAR selector is in DOWN position.
What is the first action to take to extend the landing gear?
Turn the ELECT MASTER switch ON.
What happens when the ELECT MASTER switch is turned ON?
The hydraulic pump will run briefly to re-pressurize the system.
At what pressure does the pressure switch deactivate the hydraulic pump?
1650 PSI.
CAUTION: What should be done if the hydraulic pump runs for longer than 20 seconds after turning ON the ELECT MASTER switch?
Discontinue flight preparations and have the system inspected by an authorized mechanic.
What happens to each gear actuator during retraction?
Each gear actuator becomes longer in order to retract the gear.
What is the required hydraulic pressure to achieve retraction of the landing gear?
1400 to 1650 PSI
What position must the LANDING GEAR selector be in to retract the gear?
UP position
What is the role of electrically-controlled extend and retract solenoids?
Route equal hydraulic pressure to both sides of each actuator.
How does differential pressure contribute to gear retraction?
Greater surface area on the retraction side of each actuator’s piston creates differential pressure, causing the gear to retract.
What maintains the gear in the retracted position?
Continuous hydraulic pressure inside the actuators.
How do the main gear and nose gear retract?
Each main gear retracts inboard into the center wing and the nose gear retracts forward.
What activates the hydraulic pump if pressure drops below 1400 PSI?
The hydraulic pump will activate.
What is the normal maximum hydraulic pressure?
1800 PSI
What does the emergency relief valve limit the maximum hydraulic pressure to?
2600 PSI
What happens to the landing gear if hydraulic pressure is lost in flight?
The gear should free-fall into the down-and-locked position.
What is required for the gear to extend while airborne?
Gear selector in DOWN position
What occurs to the extend solenoid during gear extension?
Extend solenoid is de-energized, causing fluid to flow into the extend side of each actuator.
What happens to fluid from the retract side during gear extension?
Fluid flows back into the fluid reservoir.
What happens once each gear is fully extended?
The pump will continue to run to increase system pressure.
What deactivates the hydraulic pump during gear extension?
Once system pressure reaches 1650 PSI, a pressure switch deactivates the pump.
Fill in the blank: Each landing gear actuator becomes _______ in order to extend the gear into the down-and-locked position.
[shorter]
What does pulling the emergency gear extension handle do?
Electrically disables the hydraulic pump, opens the emergency extension valve, releases hydraulic pressure, and allows fluid to flow back into the reservoir.
Gravity will help extend the gear.
How long may the emergency gear extension take to complete?
Up to 20 seconds.
What is the first step in the emergency gear extension procedure?
Push GEAR/FIRE TEST button to verify indicator lights are functioning.
What should be verified after pushing the GEAR/FIRE TEST button?
Verify ELECT MASTER switch On.
What is the required bus voltage range for the emergency gear extension?
24.1 to 28.5 VDC.
What position should the GEAR handle be in for emergency gear extension?
DOWN position.
What speed must be reduced below for emergency gear extension?
VLO 156 KIAS (152 KIAS if equipped with GFC 700 autopilot).
What is the speed requirement for emergency gear extension in the DA42NG?
Reduce speed below VLO 152 KIAS.
What action is taken after reducing speed in the DA42NG for emergency gear extension?
Pull the Manual Gear Extension handle.
What actions should be taken to obtain green down-and-locked indications during emergency gear extension?
Use moderate yawing and pitching.
What does the Gear/Fire Test check?
Engine fire detection system and landing gear indicator lights
It ensures that both systems are functioning correctly.
What alarm is activated during the Gear/Fire Test?
A repeating chime alarm
This alerts the crew to check the systems.
What displays are shown during the Gear/Fire Test?
L/R ENG FIRE and CHECK GEAR on the PFD
These messages indicate the status of the engine fire detection and landing gear.
What should be done if a burned-out indicator light is suspected?
Press the GEAR/FIRE switch
This action is recommended to verify the status of the indicator lights.
What effect does setting the Instrument Light dimmer knob to a low setting during the day have?
Makes the green gear position indicator lights appear inoperative
This can lead to confusion regarding the gear status.
What is the purpose of the spring assembly on the nose gear?
Centers the nose wheel once the aircraft is airborne to prevent tire contact with the gear doors during retraction
This mechanism aids in the proper functioning of the gear system.
What is a common error during taxi operations?
Over-reliance on differential power and braking to turn the aircraft instead of using rudder pedals
This can lead to ineffective turns and control issues.
Why should retread tires not be installed on the nose gear?
Due to their larger size and the risk of a tire becoming jammed inside the wheel well
This can cause significant operational hazards.
How many down-lock microswitches are there on the nose gear?
Two
One is near the down-lock hook, and the other is on top of the stay arm.
What must occur for the green nose gear light to illuminate?
Both down-lock microswitches must close
This indicates that the nose gear is properly locked in place.
Where is the nose gear up/limit switch located?
Inside the wheel well
This switch controls the indication of the gear status.
What activates the Gear Unsafe light?
Microswitch located near the aft side opening of the nose gear wheel well
This indicates potential issues with the gear system.
Where is the down/lock switch located on each main gear?
On the inboard side
This switch closes when the gear is fully extended.
What does the up-limit switch on each main gear do?
Closes when the gear is fully retracted
This is crucial for the gear status indication.
Where are squat switches located on the main gear?
On the front side, protected by a black plastic shroud
These switches play a key role in preventing accidental gear retraction.
What does the squat switch on the left main landing gear prevent?
Prevents gear retraction if the gear selector is set to UP while the aircraft is on the ground
This is important to avoid damage to the aircraft.
What happens if PITOT HEAT is turned ON on the ground?
STAL HT FAIL will be displayed on the PFD after 8 seconds
This indicates a failure in the stall heat system.
What should you not do once the gear is in transit?
Do not move the gear selector until the gear cycle has completed
What is VLOE for gear extension in KIAS?
194 KIAS (188 KIAS if equipped with GFC 700 autopilot)
What is VLOR for gear retraction in KIAS?
Do not attempt to retract the gear at indicated airspeeds above 156 KIAS (152 KIAS if equipped with GFC 700 autopilot)
What is the VLOE for the DA42NG?
188 KIAS
What is the VLOR for the DA42NG?
Do not attempt to retract the gear at indicated airspeeds above 152 KIAS
Under what conditions will the gear warning horn sound?
When gear is not down-and-locked and any of the following conditions exist:
* Engine power below 25% selected on either engine
* Flaps LDG
* Gear UP while on the ground
What is the recommended PSI for the nose tire?
87 PSI (6.0 bar)
What is the recommended PSI for the main tires?
68 PSI (4.7 bar), 65 PSI if OÄM 42-195 is not installed
What does the red dot on the tire sidewall indicate?
Tire’s point of lowest mass
How is the red slip mark aligned during tire installation?
Aligned with valve stem which is the heaviest mass on the inner tube
What type of brakes are used in the Diamond DA42?
Disc type brakes and calipers on each main wheel
How are the brakes actuated in the Diamond DA42?
Hydraulically actuated by a corresponding toe brake on the left or right rudder pedal
How many brake cylinders are there for the pilot and co-pilot in the Diamond DA42?
Four brake cylinders, one on each pedal for the pilot and co-pilot
How are the brake cylinders plumbed in the Diamond DA42?
Plumbed in series and share the same brake fluid reservoirs
Where are the brake fluid reservoirs located in the Diamond DA42?
Located on the co-pilot’s side
What may happen if there is a low brake fluid level in the Diamond DA42?
The co-pilot brakes may fail while the pilot side brakes continue to function
When should the pilot and co-pilot brakes be tested in the Diamond DA42?
Immediately when starting to taxi
What is the function of the PARKING BRAKE lever?
Stores hydraulic brake pressure by moving to the LOCK position and pumping both brake pedals two or three times
What should be avoided regarding the parking brake?
Do not set the parking brake for extended periods
What are recommended safety measures when parking the aircraft?
Wheel chocks and tie-downs are recommended
What does the CHECK GEAR CAS message indicate?
It is a warning related to the landing gear status
What does the STAL HT FAIL CAS message indicate?
It is a warning related to stall heat failure
