Showing papers on "Landing gear published in 2001"

System and method for controlling traveling direction of aircraft

Abstract: The present invention is structured such that, as for travelling on the ground, there is provided a braking mechanism capable of braking wheels by the use of a single brake pedal or a braking mechanism capable of braking the wheels by flare out operation of a control stick, while automatic control of traveling direction is performed in flight using a yaw damper In addition, a larger braking force is automatically generated, without manual operations by a pilot, for landing gear mounted on the side of an airframe toward which direction of an aircraft is to be changed as compared with the braking force applied to landing gear on the other side

System and apparatus for determining the center of gravity of an aircraft

Abstract: A method and apparatus for determining the center of gravity of an aircraft having a plurality of wheels includes the steps of determining the load on one of the plurality of aircraft wheels, determining the aircraft inclination with respect to level, relating the wheel load to the aircraft center of gravity based on the aircraft inclination. The load determination may be conducted by measuring the load on the nose wheel or at some selected point along the longitudinal axis spaced from the main landing gear. An inclinometer is used to measure the aircraft inclination at the time the load is determined. A processor may be provided for receiving the load cell signal and inclination information, and determining wheel load.

Stiffness de-coupled skid landing gear

Abstract: A skid landing gear for a helicopter, in which the directional stiffnesses of the cross members of the skid landing gear have been de-coupled from one another, such that optimization of the longitudinal stiffniess of the cross members may be performed independently of the optimization of the vertical stiffniess and fatigue life of the cross members. In order to de-couple the stiffnesses in the skid type landing gear, two approaches are employed. In the first approach, the skid landing gear has non-symmetric-section cross members and/or distribution of different materials within the cross-section for de-coupling the vertical stiffness of the cross members from the longitudinal stiffness, such that placement of the ground resonance frequency may be optimized, while retaining the vertical stiffness properties essential for optimizing vertical energy attenuation and fatigue life. In the second approach, mounting devices are employed that provide compliance in selected directions, thereby de-coupling the directional stiffnesses.

Flight testing of the F/A-18E/F automatic carrier landing system

Abstract: The F/A-18E/F is the U.S. Navy's premier strike fighter aircraft, manufactured by the Boeing Company. The F/A-18E/F aircraft, while maintaining a high degree of commonality with the F/A-18C/D aircraft, has a lengthened fuselage, larger wing and control surfaces, strengthened landing gear, an improved propulsion system including a growth version of the General Electric F404 engine designated the F414-GE-400, and larger high performance inlets. This paper concentrates on the development, test, and evaluation of the F/A-18E/F Automatic Carrier Landing System (ACLS) up to and including the Third Sea Trials, upon which the aircraft was initially qualified for Mode I, totally automatic, approaches and landings to the aircraft carrier. The paper briefly describes the key components of the F/A-18E/F's ACLS, including cockpit displays and controls, antennas, autothrottles and flight control implementation, and interface with the shipboard AN/SPN-46(V) ACLS. Test procedures and methodology are presented as well as test results and interpretation. Finally, lessons learned are presented and recommendations are made for future aircraft ACLS developmental test and evaluation efforts.

Architecture for the hydraulic braking system of an aircraft

Abstract: The invention relates to an architecture for a hydraulic braking system suitable for an aircraft of the type having at least one group of main landing gear units, each landing gear unit comprising a determined number of wheels each provided with a hydraulically actuated brake, the or each landing gear group being associated with a hydraulic circuit provided with hydraulic equipment and adapted to deliver hydraulic fluid under pressure to all of the brakes of the landing gear group, the hydraulic fluid being pressurized by at least one aircraft pressure generator system associated with an aircraft hydraulic fluid supply. According to the invention, accumulators are connected on the or each circuit in sufficient number for each accumulator to feed two pairs of brakes, each pair of brakes being mounted on a distinct landing gear unit, and an electrically-driven pump being arranged to maintain a predetermined pressure level in all of the accumulators of the circuit in question.

Support system for ground testing an aircraft

Abstract: The invention is a system for supporting a vertical take off and landing aircraft during hover tests about the ground, the aircraft having a longitudinal, vertical, and lateral axis, a nose landing gear and a main landing gear positioned rear therefrom on either side of the longitudinal axis. In detail, the system includes a bearing assembly, preferably and air bearing assembly positionable under the nose and each main landing gear. An air cushion assembly mounted to each of the air bearings with the air cushion assembly detachably coupled to each landing gear. Preferably, the air cushion assemblies are coupled to the landing wheel axles. Thus the bearing assemblies allow horizontal motion above the ground and the air cushion provides for vertical movement of the aircraft above the ground.

Device for testing range of buffer for undercarriage unit landing shocks

Abstract: The utility model relates to a travel test unit of a landing gear drop impact buffer, which is characterized in that a photoelectric encoder is connected with a displacement test wheel. A displacement transmission strip is contacted with the displacement test wheel in a flexible sliding friction mode. A rolling-shaped tension spring is connected with the displacement transmission strip. The upper side and the lower side of the displacement test wheel are respectively provided with a guiding press wheel. The photoelectric encoder, the displacement test wheel, the guiding press wheel and the rolling-shaped tension spring are fixed to a main shaft of a landing gear by a detachable movable connecting component so as to ensure that the structure and the strength of landing gear airplane wheels can not be damaged. The utility model has the advantages that the displacement test wheel is contacted with the displacement transmission strip in a flexible mode, and therefore, the photoelectric encoder can exactly measure rotation pulse data by the rotation angle variation of the displacement test wheel under the condition of strong impact vibration. The dynamic variation process of the momentary landing gear buffer travel of airplane landing can be calculated by a computer.

Airplane landing gear suspension and shock-absorbing device

Abstract: A shock absorber that uses polyurethane discs for aircraft landing gear. The discs are maintained under compression. When the aircraft lands or taxis, loads further compress the discs. Unlike bungee cords, however, the discs do not release their energy immediately. Rather, they release the energy slowly, which produces a smoother reaction to loads that eliminates any bounce back of the aircraft.

Landing gear for model airplane

Abstract: A landing gear for a model airplane featuring a support structure that is spring loaded to permit controlled resilient tilting of the support structure thereby absorbing the shear impulses to which a plane is is otherwise subject to. A pair of springs is mounted on the outside of the plane and supports the union section of a yoke with attached wheels against the plane body. fasteners attaching landing gear to plane body provide sufficient range in two degrees of freedom to permit rearward/forward and sideways tilt of the landing gear.

Wheel rotation device

Abstract: This invention relates to a system for reducing tire wear of an airborne vehicle that requires a runway upon which to land. A stream of air is naturally directed against a mechanical housing affixed to the wheels of the airborne vehicle, the device comprising a number of radially spaced surfaces symmetrically positioned about the housing and bolted to the existing wheel assembly. When the landing gear is in the extended position, natural air flow across the radially spaced surfaces causes the wheel to rotate at the equivalent to the landing speed of the aircraft, eliminating excessive wear on the tire, reducing stress on the landing gear assembly and resulting in a more controlled landing.

Receiving vehicle for plane forced-landing resulted from failure of landing-gear

Abstract: The utility model relates to a receiving vehicle for airplane forced-landing resulted from failure of landing gear, which belongs to the aviation service domain. The utility model is composed of a jet engine, a chassis, a car body, an emission, feedback and signal testing apparatus, a driving control device, a damping device, a power device, a steering device, a braking device, an oil tank and other auxiliary devices. The utility model realizes the safe landing of the failure landing gear of an airplane, and is suitable for the airplanes of heavy duty, medium size and light size. The receiving vehicle for airplane forced-landing resulted from failure of landing gear is suitable for civil aviation airplanes as well as military airplanes and other airplanes.

Landing gear simulator and trainer

Abstract: A device is disclosed for training pilots by simulating the operation of retractable landing gear in aircraft. The self-contained device can be installed into fixed landing gear aircraft to be used during takeoff and landing. Alternatively, the device can be used during classroom and ground school training. A switch box control panel simulates the landing gear controls and indicators of retractable gear aircraft. A logic circuit and program simulate landing gear operation, in “simulator” mode, and common landing gear errors of retractable gear aircraft in “trainer” mode. In “trainer” mode, the program and circuit also randomly alert the pilot to common landing gear errors and evaluate the pilot's corrective control input, outputting an error indication if the pilot's response is incorrect. The device's capabilities to accept flight control inputs and to emulate characteristics of specific retractable gear aircraft increase the realism of the simulation and training.

Transverse Elastic–Friction Vibrations of a Running Aircraft

Abstract: An analytical model of the plane-parallel running of an aircraft under crosswind load is proposed. The compliance of the internal constraints of the aircraft and the nonlinearity of the side force on the landing gear wheels are taken into account. The model is intended to study the transverse elastic friction vibrations of the aircraft hull and landing gears. The steady motion of the aircraft is considered. The dependence of the lateral friction force on the slip angle is assumed to have the form of a sinusoidal segment. The Routh–Hurwitz instability conditions are derived in an explicit form

Assembling structure for landing gear of a model airplane

Abstract: An assembling structure for landing gear of a model airplane, including an airplane body having a base board on which a landing gear fixing seat mounted. The landing gear is fixed on the fixing seat by fixing pins passing through the fixing seat. The cap section of the fixing pin can be rotated by 90 degrees to engage in a channel of the fixing section of the landing gear. Under such circumstance, the landing gear is disengaged from the cap section of the fixing pin and can be quickly disassembled from the fixing seat and separated from the airplane body. Accordingly, the model airplane body and the landing gear can be quickly assembled and disassembled to facilitate carriage and storage of the model airplane.

Business Jet Crash Landing Analysis

Abstract: The FAA is considering revising existing regulations pertaining to emergency landing. These regulations state that no fuel should be released in or near the fuselage or engines in quantities sufficient to start a fire in otherwise survivable crash landing conditions. The all landing gear retracted condition is critical for lowwing business jet aircraft, since the primary impact can occur directly on a wet region of the wing. In addition, the wing lower surface can be in direct contact with the runway during the sliding phase, and must be protected from wear-through due to abrasion and must disperse heat generated by friction. Recent business jet gear-up landing incidents are discussed, with focus on fuel tank and aircraft damage incurred during the impact and sliding transients. The methods utilized to model crash landing transients are outlined, and the aircraft loads from simulations are presented. The results from sliding simulations, with focus on abrasion and heat transfer analyses, are also presented.

Warning device for aircraft towing vehicle

Abstract: PROBLEM TO BE SOLVED: To provide a warning device for an aircraft towing vehicle that prevents a turn of an aircraft towing vehicle from damaging a front landing gear. SOLUTION: The oil pressures of cylinders holding a front landing wheel are detected, and from the oil pressures, torque acting on a front landing gear is computed. A determination of excessive torque triggers a warning.

Landing Gear Shimmy and Directional Stability of Aircraft Undergoing Non-Straight Taxiing

Abstract: A dynamic model of landing gear struts is introduced in a non-inertial coordinate system. Together with a six degrees of freedom model of aircraft ground handling, the model can be applied to investigate the landing gear shimmy and the directional stability of aircraft undergoing non-straight taxiing. Take the K8 aircraft as an example, motions of the strut under both the straight and non-straight taxiing are simulated as well as the directional adjusting procedure of the airframe. Results of the example are reasonable, indicating that the model may have some value in related research.

Non-expandable aero-space system

Abstract: aeronautical and space engineering. SUBSTANCE: system includes transport spacecraft provided wit main and auxiliary engine plants, propellant tanks, control units, aerodynamic control surfaces, crew cabin, landing gear and cryogenic stage. System is provided with four cryogenic stages. First stage is made in form of high-speed launch vehicle whose casing is made in form of wing for forming aerodynamic lift force and hydrofoils. Second stage is made in form of aircraft whose casing is also made in form of wing and stabilizer provided with horizontal tail for forming aerodynamic lift force and secured on vertical fins; it is provided with silo having changeable platform. Third stage is made in form of cylindrical launch vehicle. Fourth stage is made in form of spacecraft whose casing has form of wing on which joint units and locks are mounted for connection with third-stage launch vehicle. EFFECT: low cost of delivery of payload to near-earth orbit. 8 dwg

Performance modeling of takeoff/landing for kt-1 aircraft

Abstract: A study on the extraction of KT-1 takeoff/landing performance was conducted through the development of the simulation program, which was validated by flight test. Longitudinal 3 DOF equations of motion were solved in conjunction with the modeling of aerodynamics, thrust, landing gear dynamics, control scheme, etc. to simulate the Kr-i trajectories and attitudes during takeoff/landing flight tests. In flight tests, the takeoff/landing trajectories were measured using grid and kinetheodolite tracking method and the grid method was shown to be very useful to measure the trajectories even though very simple. The simulated takeoff/landing distances at test conditions showed little discrepancy as compared to those of flight tests and the simulated control surface displacements, angle of attack, pitch attitude, acceleration also showed good agreements with test data.