Safety and Reliability Aspects of an Adaptive Trailing Edge Device (ATED)

In morphing structures, actuation is a key system for general aircraft-level functions. Similarly to the demonstration of safety compliance applied to aircraft control surfaces, novel functions resulting from the integration of a morphing device (ATED), imposes a detailed examination of the associated risks. Because of the concept novelty, literature references for a safe design of a morphing trailing edge device are hard to be found. The safety-driven design of ATED requires a thorough examination of the potential hazards resulting from operational faults involving either the actuation chain, such as jamming, or the external interfaces, such as loss of power supplies and control lanes. In this work, a study of ATED functions is qualitatively performed at both subsystem and aircraft levels to identify potential design faults, maintenance and crew faults, as well as external environment risks. The severity of the hazard effects is determined and placed in specific classes, indicative of the maximum tolerable probability of occurrence for a specific event, resulting in safety design objectives. A fault tree is finally produced to evaluate the impact of actuation kinematics on specific aspects of ATED morphing operation and reliability.