Validation of the safety requirements of the landing gear using fault tree analysis

Iven, Leander; Zaidi, Yaseen

Abstract

We analyze the functionality of the landing system of a regional aircraft in the extension and cruise flight modes and validate safety requirements through the fault tree analysis. The main landing gear system is captured in the electromechanical–fluidic domain and system behavior is abstracted in an elementary hydraulic circuit. The functional representation is then constructed into a fault tree which allows analysis of the failure propagation originating at different branch terminals, for instance, at the main landing gear actuator which extends the gear and holds it retracted during the cruise, door actuator, door uplocks, and hydraulic power supply. Each component is assigned a failure probability. Each failure mode is abstracted as a top-level event having a probability of failure and through Boolean combinations of component failures in the lower branches. Two reliability aspects considered are the availability to fully lower the landing gear and the integrity of inadvertent gear or door extension while cruising. Architectural changes through undercarriage system reconfiguration and component redundancy have been exploited to improve system failure rates. The analysis determines the overall system failure rate against the flight cycles. The process is agile to accommodate design changes with the evolution of architecture during the systems engineering lifecycle.

• Journal Article Type: Article
• Acceptance Date: Jan 27, 2022
• Online Publication Date: Mar 12, 2022
• Publication Date: Apr 1, 2022
• Deposit Date: Mar 12, 2022
• Publicly Available Date: Mar 15, 2022
• Journal: CEAS Aeronautical Journal
• Print ISSN: 1869-5582
• Electronic ISSN: 1869-5590
• Publisher: Springer (part of Springer Nature)
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Pages: 503-520
• DOI: https://doi.org/10.1007/s13272-022-00572-8
• Keywords: aerospace engineering; landing gear, safety
• Public URL: https://uwe-repository.worktribe.com/output/9206283
• Publisher URL: https://link.springer.com/article/10.1007/s13272-022-00572-8
• Additional Information: Received: 31 December 2020; Revised: 24 January 2022; Accepted: 27 January 2022; First Online: 12 March 2022