Aircraft Landing Gear System Quiz
87 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a primary function of the main landing gear in an aircraft?

  • To enhance visibility from the cockpit
  • To provide steering capability during taxiing
  • To prevent ground-looping during landing
  • To absorb download forces during ground operations (correct)

    • Which of the following is NOT a benefit of tricycle configuration landing gear?

  • Enhances the overall payload capacity (correct)
  • Allows higher landing speeds without nosing over
  • Prevents ground-looping of the aircraft
  • Improves visibility during ground manoeuvring

    • What role do shimmy dampers play in the landing gear system?

  • They facilitate the steering of the nose landing gear
  • They stabilize the aircraft during ground movements (correct)
  • They aid in the emergency retraction of the landing gear
  • They help absorb shocks during landing

    • Which landing gear configuration is typically used for rough field operations?

    <p>Conventional configuration</p> Signup and view all the answers

    How does the nose landing gear typically contribute to aircraft handling?

    <p>By allowing the aircraft to steer during ground operations</p> Signup and view all the answers

    What is the main advantage of a tricycle landing gear over a tail-wheel configuration regarding braking?

    <p>Enables a more forceful application of brakes without nosing over</p> Signup and view all the answers

    What is generally required for retracting and extending the landing gear?

    <p>Hydraulic or pneumatic power systems</p> Signup and view all the answers

    What is the maximum force exerted by the retract actuator for the main landing gear?

    <p>53,000 N</p> Signup and view all the answers

    What is the flow rate required to retract the three actuators in cubic meters per second?

    <p>0.0263 m³/s</p> Signup and view all the answers

    What is the power in kilowatts required to drive the pump, assuming an efficiency of 85%?

    <p>640 KW</p> Signup and view all the answers

    Which component prevents undesired retraction of the landing gear when it is in the ‘DOWN’ position?

    <p>Overcenter links</p> Signup and view all the answers

    What happens to the uplock mechanism after the landing gear is unlocked?

    <p>It extends due to its mass and locks in the down position</p> Signup and view all the answers

    What is the primary function of an aircraft wheel?

    <p>To support the aircraft's weight during various phases of flight</p> Signup and view all the answers

    What role does the trunnion play in the landing gear assembly?

    <p>It allows the gear to pivot during retraction and extension</p> Signup and view all the answers

    Which component is responsible for locking the landing gear in the down position?

    <p>Downlock Mechanism</p> Signup and view all the answers

    What is the primary function of the drag link in the landing gear assembly?

    <p>To provide support to the shock strut longitudinally</p> Signup and view all the answers

    How does the overcenter link contribute to the functionality of the landing gear?

    <p>It prevents the link from pivoting during gear retraction</p> Signup and view all the answers

    What material are typical aircraft wheels commonly made from?

    <p>Aluminum alloy</p> Signup and view all the answers

    What is a key function of aircraft tires?

    <p>To provide grip with the runway surface</p> Signup and view all the answers

    Which component stabilizes the landing gear laterally?

    <p>Side Strut or Side Brace Link</p> Signup and view all the answers

    What is the main purpose of the axles in the landing gear system?

    <p>To support and install the main wheels</p> Signup and view all the answers

    What method is NOT used by landing gear to absorb shock during landing?

    <p>Transferring force through the airframe at a consistent rate</p> Signup and view all the answers

    In a pneumatic/hydraulic shock strut, what is the role of the nitrogen gas?

    <p>To maintain pressure in the upper chamber</p> Signup and view all the answers

    What happens to the volume of gas in the upper chamber during the compression stroke of the shock strut?

    <p>It decreases, leading to increased pressure</p> Signup and view all the answers

    What is the immediate effect of the aircraft's wheels touching the ground on the shock strut?

    <p>The compression stroke of the shock strut begins</p> Signup and view all the answers

    What is a disadvantage of non-shock absorbing landing gear?

    <p>It can lead to harmful forces being transferred to the airframe</p> Signup and view all the answers

    Which component primarily allows hydraulic fluid to move between the chambers during compression?

    <p>Orifice</p> Signup and view all the answers

    What effect does increasing pressure in the shock strut have on the aircraft’s vertical motion?

    <p>It stops vertical motion</p> Signup and view all the answers

    What is a characteristic of flexible spring steel used in non-shock absorbing landing gear?

    <p>It returns to its original shape after flexing</p> Signup and view all the answers

    During the landing process, what role does the hydraulic fluid play in the shock strut?

    <p>It helps cushion the shock by being forced through a metered opening</p> Signup and view all the answers

    What is the role of compressed air in the shock strut of an aircraft during takeoff?

    <p>It acts as a shock absorber while the aircraft is taxiing.</p> Signup and view all the answers

    What is a disadvantage of having fixed landing gear on an aircraft?

    <p>It exposes the gears to airflow, increasing drag.</p> Signup and view all the answers

    How does the weight of retractable landing gear compare to its benefits?

    <p>The added weight is considered a minor drawback compared to the reduction in drag.</p> Signup and view all the answers

    What happens to the landing gear components when the landing gear handle is set to 'OFF'?

    <p>They are connected to the return line of the hydraulic system to maintain the 'UP' position.</p> Signup and view all the answers

    Which mechanism is responsible for keeping the landing gear in the 'UP' position?

    <p>Up-lock mechanism.</p> Signup and view all the answers

    What function do the unlatch and door actuators serve in the landing gear system?

    <p>They unlock and open the wheel well doors.</p> Signup and view all the answers

    What happens when the landing gear handle is set to the 'DOWN' position?

    <p>Pressure from the hydraulic system is released to extend the landing gear.</p> Signup and view all the answers

    What is the mechanical connection of the landing gear handle in the cockpit responsible for?

    <p>Controlling the hydraulic pressure supply for landing gear operation.</p> Signup and view all the answers

    During takeoff, which of the following describes the process of shock strut extension?

    <p>The shock strut extends until gas pressure can fully support the aircraft's weight.</p> Signup and view all the answers

    What mechanism prevents the nose wheel from rotating, ensuring proper wheel alignment?

    <p>Torque links</p> Signup and view all the answers

    How does the hydraulic pressure affect the nose steering during a right turn?

    <p>It directs fluid through the right turn alternating line to cylinder A.</p> Signup and view all the answers

    What keeps the nose landing gear aligned when the shock strut is fully extended?

    <p>Locating cam assembly</p> Signup and view all the answers

    What component adjusts the steering direction based on the nose gear shock strut position?

    <p>Tiller</p> Signup and view all the answers

    During aircraft taxying, how can the aircraft be steered?

    <p>Utilizing nose wheel steering or differential braking.</p> Signup and view all the answers

    What happens to the hydraulic fluid in the steering system during a left turn?

    <p>It is forced out of steering cylinder B.</p> Signup and view all the answers

    What is the result of hydraulic fluid flowing away from the retraction actuator?

    <p>It reduces the ‘down’ shock upon retraction.</p> Signup and view all the answers

    How does the cam assembly contribute to the landing gear system?

    <p>It keeps the wheel aligned once extended.</p> Signup and view all the answers

    What is the primary function of a shimmy damper in a nose landing gear system?

    <p>To reduce the tendency of the nose gear to oscillate</p> Signup and view all the answers

    How does the emergency extension system operate when the main power fails?

    <p>It mechanically releases the uplocks via a handle</p> Signup and view all the answers

    What role does the squat switch play in the landing gear system?

    <p>To indicate the compression or extension of the gear strut</p> Signup and view all the answers

    Which statement best describes the function of ground locks in the landing gear system?

    <p>They restrict movement of the gear to prevent collapse on the ground</p> Signup and view all the answers

    What is the primary mechanism by which a piston-type shimmy damper absorbs oscillations?

    <p>Restriction of hydraulic fluid through a bleed hole</p> Signup and view all the answers

    What happens when the landing gear safety switch is closed?

    <p>Current flows to retract the land gear pin</p> Signup and view all the answers

    Which aspect of emergency extension systems can vary between different aircraft?

    <p>Method to unlatch the gear</p> Signup and view all the answers

    What is the likely consequence of a malfunctioning squat switch during ground operations?

    <p>Gear may inadvertently retract while on the ground</p> Signup and view all the answers

    What is one of the main advantages of a tricycle landing gear configuration over a tail wheel configuration?

    <p>It prevents ground-looping of the aircraft.</p> Signup and view all the answers

    Which landing gear configuration is typically associated with older aircraft designed for rough field operations?

    <p>Conventional configuration</p> Signup and view all the answers

    What primary function does the main landing gear serve during aircraft ground operations?

    <p>To absorb large download forces during landing and taxiing.</p> Signup and view all the answers

    How does the nose landing gear typically enhance aircraft operation on the ground?

    <p>It allows for better visibility and steering capabilities.</p> Signup and view all the answers

    What is an important feature of the shock-absorbing element in the landing gear?

    <p>It absorbs shock during landing to minimize impact forces.</p> Signup and view all the answers

    Which statement about the brake systems on the main landing gear is correct?

    <p>Brakes are installed to assist in slowing down or stopping the aircraft during ground operations.</p> Signup and view all the answers

    In a hydraulic shock strut, what effect does increasing the pressure in the system generally have?

    <p>It increases the aircraft's vertical motion.</p> Signup and view all the answers

    What is a key advantage of tricycle landing gear concerning visibility during landing?

    <p>It allows pilots to see directly down the runway.</p> Signup and view all the answers

    What is the primary role of the hydraulic pressure in the landing gear system?

    <p>To unlock and operate the landing gear mechanisms</p> Signup and view all the answers

    How much volume is required to retract three actuators of the landing gear?

    <p>0.263 m³</p> Signup and view all the answers

    What is the role of the overcenter mechanism in the landing gear system?

    <p>To prevent the landing gear from retracting while down</p> Signup and view all the answers

    Which factor does NOT influence the calculation of the power required for the pump?

    <p>Weight of the aircraft</p> Signup and view all the answers

    What is the maximum force exerted by each retract actuator in the landing gear system?

    <p>53,000 N</p> Signup and view all the answers

    What mechanism converts hydraulic power into mechanical motion in the landing gear system?

    <p>Actuators</p> Signup and view all the answers

    How does the uplock mechanism secure the landing gear?

    <p>Through a physical hook that engages the gear</p> Signup and view all the answers

    What is the function of bungee springs in the landing gear system?

    <p>To provide a counterforce for gear extension</p> Signup and view all the answers

    What is the primary reason for installing retractable landing gear in aircraft?

    <p>To reduce drag during flight</p> Signup and view all the answers

    Which action occurs when the landing gear handle is placed in the 'UP' position?

    <p>Hydraulic pressure supplies energy to unlock and open the wheel well doors</p> Signup and view all the answers

    How does the hydraulic power system affect the landing gear when set to the 'OFF' position?

    <p>All components are connected to the return line, keeping the landing gear up</p> Signup and view all the answers

    What is the role of the up-lock mechanism in the landing gear system?

    <p>To automatically lock the landing gear in the up position</p> Signup and view all the answers

    In the landing gear system, what is the purpose of the retract actuator?

    <p>To apply hydraulic pressure for gear retraction</p> Signup and view all the answers

    What occurs to the compressed air in the shock strut during the recoil of the aircraft?

    <p>It compresses further, increasing support for the aircraft’s weight</p> Signup and view all the answers

    What happens to the hydraulic system's pressure when the landing gear handle is set to 'DOWN'?

    <p>Pressure is released, allowing gear extension</p> Signup and view all the answers

    During taxiing, what role does the compressed air in the shock strut play?

    <p>It absorbs shock and stabilizes the aircraft</p> Signup and view all the answers

    What is a consequence of the hydraulic fluid being forced through the metered opening during the compression of a shock strut?

    <p>It cushions the initial shock of landing.</p> Signup and view all the answers

    Which characteristic of non-shock absorbing landing gear allows it to manage landing impact?

    <p>It flexes initially to absorb and dissipate forces.</p> Signup and view all the answers

    During the compression stroke, what happens to the gas pressure in the upper chamber of the shock strut?

    <p>It increases due to the decrease in gas volume.</p> Signup and view all the answers

    What is the primary role of the metering pin within a shock strut during the aircraft's landing?

    <p>To adjust the rate of fluid transfer to control damping.</p> Signup and view all the answers

    What distinguishes shock absorbing landing gear designs from non-shock absorbing designs?

    <p>They incorporate hydraulic and gas mechanisms to dissociate impact forces.</p> Signup and view all the answers

    How does the positioning of the aircraft's center of mass affect the operation of shock struts during landing?

    <p>A downward movement assists in the fluid transfer during compression.</p> Signup and view all the answers

    What happens to the temperature within the shock strut as the pressure increases during compression?

    <p>It increases because of hydraulic fluid going through compression.</p> Signup and view all the answers

    What is the function of the orifice in the shock strut mechanism during the compression stroke?

    <p>To regulate the transfer of hydraulic fluid from the lower to the upper chamber.</p> Signup and view all the answers

    Study Notes

    Aircraft Systems - Hydraulic and Pneumatic Power Systems

    • ME3531 is the course code for Aircraft Systems at Singapore Polytechnic.
    • The course content covers Hydraulic and Pneumatic Power Systems.
    • The course includes a detailed study of the Landing Gear System with specific topics to be covered.

    Landing Gear System

    • Configurations: Different configurations of aircraft landing gear will be stated and described.
    • Operating Principles: The operating principles of main and nose-landing gear will be discussed.
    • Components: The functions of various landing gear components (struts, torque links, drag links, side struts, shimmy dampers, axles, wheels, and tires) will be described.
    • Shock Absorbing Element: The construction and function of the shock absorbing element in the landing gears will be explained.
    • Aircraft Steering: Aircraft steering systems will be discussed.
    • Extension/Retraction Systems: The normal and emergency extension/retraction systems of the landing gear will be described.
    • Safety Devices: The safety devices, indications, and warning systems of the landing gear will be discussed.

    Hydraulic Power - Landing Gear System

    • Main Landing Gears: Main landing gears provide primary support, absorbing high download forces during ground operations like landing and taxiing. Brakes are installed for slowing down or stopping as required. The number of landing gears, wheels, and brakes vary based on the initial aircraft design considering weight and load capacities.
    • Nose Landing Gears: Nose landing gears also provide aircraft support, carrying load. The gears normally include steering mechanisms for manoeuvring on the ground.

    Types of Landing Gear Arrangement

    • Tail or Conventional Configuration: This is used on older aircraft for landing in rough field operations.
    • Tandem Configuration: Aircraft configuration details are not provided.
    • Tricycle Configuration: This is used in contemporary aircraft, offering advantages over conventional landing gears: forceful braking without stability loss; improved flight deck visibility (especially during landing and ground maneuvers); and prevention of ground-looping due to the aircraft's center of gravity position.

    Sub-components of the Main and Nose Landing Gear

    • Aircraft Wheels: Crucial for a landing gear system, they support the entire aircraft weight during taxiing, takeoff, and landing. Typical wheels are lightweight, strong and constructed from aluminum alloy.
    • Aircraft Tyres: Support aircraft weight, absorb shock from landing/taxiing, provide grip with runway, and discharge static electricity.
    • Trunnion: Part of the landing gear assembly, fixed to the airframe. Trunnion uses bearing assemblies for retraction/extension pivot.
    • Strut: The vertical member of the landing gear system; a diagram or complete description of the important parts involved is not given.
    • Drag Link or Drag Strut: Supports and stabilizes the strut longitudinally.
    • Side Strut or Side Brace Link: Stabilizes the landing gear laterally.
    • Overcenter Link: Prevents movement at joints during landing gear retraction, prevents collapse during ground operations. Locks main gear in down position (also called 'Downlock'), allowing hydraulic retraction.
    • Lock Mechanism: A "downlock" locks the landing gear in the down position. The main landing gear is held in the UP position by the uplock mechanism.
    • Axles: Supports and installs the main wheels on the aircraft.

    Hydraulic Power - Landing Gear System

    • Shock Absorbing and Non-Shock Absorbing Landing Gear: Landing gear absorbs forces on landing and taxiing. Absorption methods include heat conversion ("damping") or altered transfer through the airframe.
    • Non-Shock Absorbing Landing Gear: Many aircraft use flexible spring steel, aluminium, or composite struts which absorb landing impact and redistribute force to the airframe at safe rates.
    • Shock Absorbing: Common design uses nitrogen gas and hydraulic fluid in telescoping cylinders. The upper cylinder is fixed to the aircraft, and the lower-piston moves inside the upper cylinder. Two chambers are formed; the lower chamber is always full of hydraulic fluid, while the upper contains nitrogen gas. The orifice between cylinders allows fluid to move.
    • Shock Strut Operation: During landing, as the aircraft touches down, the strut compresses. The lower cylinder/piston goes up into the upper cylinder. This increases pressure within the chamber. During recoil, the strut extends until the air pressure supports the aircraft's weight, cushioning the aircraft during taxiing.

    Fixed and Retractable Landing Gear

    • Fixed Landing Gear: Exposed to airflow during flight, leading to increased drag with increasing speed.
    • Retractable Landing Gear: Mechanisms retract/stow landing gear to reduce drag, but they have some weight addition.

    Retraction and Extension of Main Landing Gear

    • Manual Operations: The main landing gear is extended/retracted using a handle on the flight deck.
    • Hydraulic Systems: The control is connected to an internal circuit in the selector valve, supplying pressure for mechanisms like unlocking wheel well doors and actuators for gear retraction and extension.
    • "UP", "OFF" (Neutral), "DOWN" Positions: Different actions occur based on handle position.
    • Up-lock Mechanism: The landing gear stays in an up position due to the uplock mechanism.
    • Down Position: Release of hydraulic pressure from internal selector valve circuit (following handle change) allows unlocking of uplock mechanism and wheel well doors, and trigger extension of the gear.

    Nose Landing Gear Steering System

    • The steering system allows aircraft maneuverability during taxying. Control is from the pilot’s station through small wheels, tillers, or joysticks. Methods include nose-wheel steer, or differential braking.

    Nose Landing Gear Alignment

    • Shock struts feature torque links/torque arms. These connect to the upper cylinder and are non-rotating, aligning the wheels.
    • Locating cam assemblies keep the landing gear in alignment. This ensures wheel/axle assembly alignment when the landing gear is extended fully. It avoids possible structural damage by aligning the wheels/axles in a straight position ahead.

    Nose Landing Gear Shimmy Dampers

    • Shimmy dampers control nose landing gear oscillations (shimmy), especially at high speeds. Reduced oscillations happen due to the proper directed flow of hydraulic fluid.
    • Piston-type dampers resist shimmy by directing hydraulic fluid flow in a controlled way through restricted openings (in a piston within the damper). This reduces any oscillations that may occur because of the structure/mechanisms.

    Emergency Extension System

    • The emergency system provides gear lowering in case of primary power failure.
    • Emergency handles in flight decks allow the landing gear to drop if the primary hydraulic system fails, using uplock release mechanism and gravity pull to the down position.
    • Some systems might use pneumatic power for unlatching the gear.

    Landing Gear Safety Devices

    • Safety Switch (Landing Gear Safety Device): Monitored the landing gear position (extended / retracted); prevents ground gear retraction.
    • Ground Locks (Landing Gear Safety Device): Prevent any collapse of landing gear while aircraft is stationary. Pins in pre-drilled holes are used.
    • Gear Indicator: Displays micro/proximity switch data (gear status) on the instrument panel. Green light shows gear is down/locked, red light shows it is in transit, and a lack of illumination signifies the gear is in the up/locked position.
    • Warning Horn: Indicates when landing gears are not down and locked (during landing).

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Aircraft Landing Gear Systems PDF

    Description

    Test your knowledge on the various functions and configurations of aircraft landing gear systems. This quiz covers topics like tricycle configurations, shimmy dampers, and the mechanics behind landing gear operation. Perfect for aviation enthusiasts and students in aerospace engineering.

    More Like This

    Aircraft Landing Gear Systems
    58 questions

    Aircraft Landing Gear Systems

    EnterprisingMagnolia avatar
    EnterprisingMagnolia
    Aircraft Landing Gear Systems
    36 questions

    Aircraft Landing Gear Systems

    BrandNewFlugelhorn6532 avatar
    BrandNewFlugelhorn6532
    Aircraft Landing Gear
    5 questions

    Aircraft Landing Gear

    IndulgentProsperity avatar
    IndulgentProsperity
    Landing Gear Systems Overview
    5 questions

    Landing Gear Systems Overview

    TollFreePreRaphaelites avatar
    TollFreePreRaphaelites
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser