Skip to main content

Research Repository

Advanced Search

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

Iven, Leander; Zaidi, Yaseen

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


Leander Iven

Yaseen Zaidi
Senior Lecturer in Systems Engineering


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
Keywords aerospace engineering; landing gear, safety
Public URL
Publisher URL
Additional Information Received: 31 December 2020; Revised: 24 January 2022; Accepted: 27 January 2022; First Online: 12 March 2022


You might also like

Downloadable Citations