The Federal Aviation Administration (FAA) has released its proposed special conditions for two magniX USA electric propulsion systems, providing the greatest detail yet on how it plans to certify electric powerplants for aviation.
The 32 special conditions were published to the Federal Register on Nov. 19. They describe how magniX must demonstrate the safety and reliability of its magni250 and magni500 model engines in order to obtain type certification of the models, which it applied for in June 2019.
Existing certification rules for aircraft engines — contained in 14 Code of Federal Regulations Part 33 — were developed for turbine and reciprocating engines that use aviation fuel as their energy source. Consequently, the FAA explains, they don’t contain “adequate or appropriate safety standards” for electric engines, which are designed, manufactured, and controlled very differently.
For novel aviation designs not adequately covered by existing regulations, the FAA is allowed to prescribe special conditions that become part of the type certification basis. To develop its special conditions for the magni250 and magni500, the FAA drew on a 2018 version of voluntary consensus technical standards developed by ASTM International, plus engine information from magniX.
The special conditions proposed by the FAA encompass a broad range of requirements relating to materials, fire protection, engine cooling, control systems, and other aspects of the system. In addition to requirements tailored specifically to electric powerplants, magniX must comply with certain applicable provisions of Part 33.
The FAA is accepting comments on the proposed special conditions until Dec. 21, 2020. The agency says it will consider all comments received and may change its proposed special conditions based on this feedback.
MagniX is a leading maker of electric powerplants for aviation. The company’s 750-horsepower (560 kW) magni500 propulsion system has powered successful flights of Harbour Air’s eBeaver and, more recently, AeroTEC’s all-electric Cessna 208B Grand Caravan.