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.

In-flight retractible landing gear training simulator for fixed landing gear aircraft

Abstract: When a pilot, fully qualified and licensed, and possibly of long accident-free experience, in the flying of fixed landing gear aircraft, desires to progress to retractible landing gear aircraft, the insurance companies require extensive flight practice with an instructor as a condition precedent to the issuance of a required insurance policy. The present invention provides a simple, compact, inexpensive simulator for installation on fixed landing gear aircraft, having (1) a manually operable actuator corresponding to the landing gear lowering actuator provided conventionally on rectractible landing gear aircraft, (2) indicator means responsive thereto for randomly simulating either correct lowering and locking of the individual landing wheels or a malfunction of one or more of the landing wheels, and (3) means corresponding to a conventional emergency landing gear lowering actuator for cancelling any indication or indications of malfunction. The simulator further includes a sounding device and a warning light for reminding the pilot that he has overlooked "lowering the landing gear" whenever he has cut the throttle without having gone through the landing gear lowering procedure, and for calling attention to the fact that not all landing gear lights are lighted when they should be.

An experimental study of applied ground loads in landing

Abstract: Results are presented of an experimental investigation made of the applied ground loads and the coefficient of friction between the tire and the ground during the wheel spin-up process in impacts of a small landing gear under controlled conditions on a concrete landing strip in the Langley impact basin. The basic investigation included three major phases: impacts with forward speed at horizontal velocities up to approximately 86 feet per second, impacts with forward speed and reverse wheel rotation to simulate horizontal velocities up to about 273 feet per second, and spin-up drop tests for comparison with the other tests. In addition to the basic investigation, supplementary tests were made to evaluate the drag-load alleviating effects of prerotating the wheel before impact so as to reduce the relative velocity between the tire and ground. In the presentation of the results, an attempt has been made to interpret the experimental data so as to obtain some insight into the physical phenomena involved in the wheel spin-up process.

외연적 유한요소기법을 활용한 리저널급 항공기 동체 내추락 특성 분석

Abstract: The impact energy absorbing is a very important characteristic of an aircraft to enhance the survivability of occupants when an aircraft is under the survivable accident such as an emergency landing condition. The impact energy is generally transmitted into the occupant and absorbed through a landing gear, a subfloor (lower structure of fuselage), and a seat. The characteristic of crash energy absorbing of a subfloor depends on the type of an aircraft, a shape of structure, and an applied material. Therefore, the study of crashworthiness characteristics of a subfloor structure is very important work to improve the safety of an aircraft. In this study, a finite element model of a narrow body fuselage section for the 80~90 seats regional aircraft was developed and crash simulation was executed using an explicit finite element analysis. Through survey of the impact energy distribution of each structural part of a fuselage and floor-level acceleration response, the crashworthiness characteristics and performance was evaluated.

Influence of landing-gear design on helicopter ground resonance

Abstract: The influence of landing-gear design on a ground-resonance phenomenon is investigated with the aid of finite-element software. Ground resonance is a vibration phenomenon that occurs at certain roto...

Directional Stability and Control During Landing Rollout

Abstract: Directional stability in landing rollout of the tricycle landing gear arrangement used in light airplanes is shown in a computer replication of a 1935 demonstration. Stability derivatives of aircraft tires are developed based on rolling tire experimental data. A small perturbation analysis using the tire stability derivatives provides a simplified model of the rollout problem, for better understanding and for checks on complete simulations. Eigenvalues in rollout are found for three cases, a sailplane, a light plane, and a large jet transport. A nonlinear transient analysis is used to verify the small perturbation model, for the sailplane case. Castering wheels are found to make negligible contributions to the eigenvalues. The position of the main gear with respect to the c.g. dominates the problem, aft gears being stable. Large airplanes with noncastering nose wheels appear to be stable in rollout over their ranges of airspeed and relative main gear to nose gear loadings. In transient analysis, banking into the swerve, a nonintuitive strategy for avoiding running off runways in side winds, is shown to be effective for bicycle gears, and in particular, for advanced sailplanes with main wheels ahead of the c.g.