SAE AIR7130

This document proposes a method to demonstrate compliance to engine certification rules requiring tolerance of the control system to single failures leading to Loss of Power Control (LOPC) or Loss of Thrust Control (LOTC) for electric or hybrid engines. At issue 1, the document was developed to address only fully electric engine configurations targeting single engine CS/part 23 level 1 and 2 aircraft applications. The methodology proposed herein is based on an alternative definition of Loss of Power Control (LOPC) proposed by EASA, the FAA, TCCA, and ANAC in a joint Decision Document. It is therefore only applicable to projects which elect to implement this authority-proposed alternative definition. Other approaches for the demonstration of compliance of electric engines to control system single fault tolerance requirements, including approaches based on legacy practices applicable to piston engines, remain possible. They are, however, outside of the scope of this document. Future issues of this report are expected to provide additional guidance for the application of the proposed method to other engine and aircraft applications. Civil aviation authorities have published Special Conditions for the airworthiness and type design of aircraft electric and hybrid engines which include requirements for the tolerance of engine control systems to single failure leading to loss of power or thrust control events. While there is a common industry-wide understanding of the scope of applicability of such requirements for traditional propulsion technologies, this is not the case for electric and hybrid engines. Furthermore, the means to accommodate loss of thrust or power control applicable to traditional propulsion technologies may not be suitable for electric and hybrid engines and some of the aircraft applications they are intended to be integrated into. The intent of this document is to provide and propose the adoption of alternative criteria to this historical approach in the context of electric and hybrid technologies based on propulsion power loss levels, their effects at the aircraft level, and acceptable failure rates.