Landing gear

About: Landing gear is a research topic. Over the lifetime, 3403 publications have been published within this topic receiving 25370 citations. The topic is also known as: landing gear & gear.

Guidance and Control Design for High-Speed Rollout and Turnoff (ROTO)

Abstract: A ROTO architecture, braking and steering control law and display designs for a research high speed Rollout and Turnoff (ROTO) system applicable to transport class aircraft are described herein. Minimum surface friction and FMS database requirements are also documented. The control law designs were developed with the aid of a non-real time simulation program incorporating airframe and gear dynamics as well as steering and braking guidance algorithms. An attainable objective of this ROTO system, as seen from the results of this study, is to assure that the studied aircraft can land with runway occupancy times less then 53 seconds. Runway occupancy time is measured from the time the aircraft crosses the runway threshold until its wing tip clears the near side of the runway. Turnoff ground speeds of 70 knots onto 30 degree exits are allowed with dry and wet surface conditions. Simulation time history and statistical data are documented herein. Parameters which were treated as variables in the simulation study include aircraft touchdown weight/speed/location, aircraft CG, runway friction, sensor noise and winds. After further design and development of the ROTO control system beyond the system developed earlier, aft CG MD-11 aircraft no longer require auto-asymmetric braking (steering) and fly-by-wire nose gear steering. However, the auto ROTO nose gear hysteresis must be less than 2 degrees. The 2 sigma dispersion certified for MD-11 CATIIIB is acceptable. Using this longitudinal dispersion, three ROTO exits are recommended at 3300, 4950 and 6750 feet past the runway threshold. The 3300 foot exit is required for MD-81 class aircraft. Designs documented in this report are valid for the assumptions/models used in this simulation. It is believed that the results will apply to the general class of transport aircraft; however further effort is required to validate this assumption for the general case.

Inertia Calculation Procedure for Preliminary Design

Abstract: : This report explains the methods involved in estimating aircraft moments of inertia for preliminary design purposes Assumptions that were made for this procedure and the derivation of equations that evolved from these assumptions are included An example using the method on the C-5A aircraft is shown This procedure requires a knowledge of the major aircraft group weights, the location of major components (landing gear, avionics bay, etc), geometry information, and inertias of some major subsystem items Using this data, the moments of inertia about the roll, pitch, and yaw axes are calculated as well as the roll-yaw cross-product of inertia

Tandem type landing gear

Abstract: The present invention relates to landing gears. The landing gear includes essentially two legs (1, 2) comprising respecitvely two arms (10, 28) and two rocker beams (3, 24), a bar (21) forming with the two arms (10, 28) a deformable parallelogram, a strut (37) consisting of two levers (23, 38) placed on a diagonal of the parallelogram, two locking links (50, 51) cooperating with the strut (37), these two rotatably mounted links being rotated by an actuator (70) and a spring (60). The landing gear finds its application in commuter aircraft fitted with tandem type landing gears.

Methods for determination of optimum sequence for automated activation of onboard aircraft weight and balance system

Abstract: A system and method for the determination for automated initiation of onboard aircraft weight and balance measurement systems. The system is used in monitoring, measuring, computing and displaying the weight and balance of aircraft utilizing telescopic landing gear struts. Pressure sensors, axle deflection sensors, and/or linkage rotation sensors are mounted in relation to each of the landing gear struts to monitor, measure and record strut and aircraft movement and rates of said movement experienced by landing gear struts, as the aircraft proceeds through typical ground and flight operations. Also, acceleration sensors and GPS can be used to monitor aircraft movements and positions during ground and flight operations. The system and method identify the position of the aircraft as related to airport ground operations to determine the optimum time to initiate an aircraft weight and balance measurement.