Landing gear is one of the critical subsystems of an aircraft. The need to design landing gear with minimum weight, minimum volume, high performance, improved life, and reduced life cycle cost have posed many challenges to landing gear designers and practitioners. Further, it is essential to reduce the landing gear design and development cycle time while meeting all the regulatory and safety re...

In recent years a clear trend has developed in the aerospace industry towards the procurement of integrated systems from major suppliers (ref. 1). In this process, Messier-Dowty became a provider of integrated landing gear systems who is responsible for supplying a certifiable landing gear system and providing all the system level performance analysis. The aircraft landing gear system retractio...

Simulation and the resulting prediction of the dynamic behavior of an aircraft and its landing gear system during ground maneuvers is an essential part in the design process. A realistic estimation of unwanted oscillations, such as gear walk and shimmy, for the landing gear and whole aircraft can be readily obtained with an MBS-model. It is then possible to adjust the model for changes in the s...

This paper deals with the study and comparison of passive and active landing gear system of  the aircraft and dynamic responses due to runway irregularities while the aircraft is taxying. The dynamic load and vibration caused by the unevenness of runway will result in airframe fatigue, discomfort of passengers and the reduction of the pilot’s ability to control the aircraft. One of the objectiv...

Integrated Vehicle Health Management (IVHM) is one of the few technologies that will help in reducing both maintenance and operational costs, while improving the overall safety of an aircraft. It also helps in moving away from conservative design philosophies. Hence IVHM is increasingly being adopted in various aircraft programs. IVHM requires a multi-disciplinary approach bringing together the...

Landing gear is a structural component of an aircraft to support the weight while it is on the ground and also to aid safe landing. A generic analytic model for linear dynamic analysis of landing gears, which captures responses of individual components, is seldom available in literature. In the present work an analytical model for the linear response analysis of landing gear is developed. The l...

In the context of aircraft, shimmy is an oscillatory phenomenon of the landing gear mainly due to the tire and the landing gear structural dynamics. This phenomenon which can result in severe damage to the landing gear must be damped. This paper presents a new nose landing gear model including an actuator model and a simple tire/road interface description approximating the Pacejka model to allo...

In the context of aircraft, shimmy is an oscillatory phenomenon of the landing gear mainly due the tire dynamics and the landing gear structural dynamics. This phenomenon, which can result in severe structural damages of the landing gear, is here actively damped by an indirect fuzzy adaptive controller. The difficulties to model the ground/wheel interface require the use of an adaptive controll...

Symbolic algebraic analysis techniques are applied to the landing gear subsystem in the new Swedish ghter aircraft, JAS 39 Gripen. Our methods are based on polyno-mials over nite elds (with Boolean algebra and propositional logic as special cases). Polynomials are used to represent the basic dynamic equations for the processes (controller and plant) as well as static properties of these. Tempor...

This paper deals with the simulation of landing gear semi-active control for a small trainer aircraft in a multibody framework. The behavior of single passive landing gear drop test simulation models and of a complete aircraft landing simulation model, developed and implemented in the commercial multibody code ADAMS in previous works, is compared to the that of analogous models equipped with se...