Bird and Tyre Impact Analysis on Landing Gear 2013-01-9002

As part of the aircraft certification process, landing gear has to be certified against particular risks such as bird and tyre impact cases.According to international aviation regulations, it has to be demonstrated that the landing gear is designed to ensure the capability for continued safe flight and landing after bird impact or after tyre impact resulting from wheel or tyre failure.Structural parts such as the down-lock mechanism must be validated against these requirements since their structural integrity is essential to ensure landing gear down-locking for landing and subsequent on ground movement.Recently, MESSIER-BUGATTI-DOWTY has been involved in the development of explicit analysis in support of bird and tyre impact justification.A model of the down-lock mechanism has been developed and a full scale test has been set up in order to demonstrate the validity of the analysis.Two extensive test campaigns have been performed considering bird and tyre impact cases using highly instrumented components to record strains and displacements on impacted parts.Based on a comparison to the test results, the modelling of bird and tyre projectiles has been validated. The computed displacements and strains in the down-lock mechanism have also been favourably compared with experimental evidence.Based on these results, a model of the complete landing gear has been built in order to take into account the effect of landing gear stiffness and to re run analysis in the complete landing gear environment.