Range Anxiety of Electric Aircraft
By Robert W. Moorman
This article is a sidebar to the author's feature story, Beta Goes the Distance, in the Nov/Dec 2023 issue of Vertiflite.
Battery performance and associated aircraft range capability remains a major area of focus for the nascent electric aircraft industry.
The General Aviation Manufacturers Association (GAMA) recognized the need for civil aviation authorities to assess battery performance for electric aircraft in a recently published white paper, “Managing Range and Endurance of Battery-Electric Aircraft.”
The report calls for “mission-specific energy hazard assessments, acceptable to civil aviation authorities, which incorporates the essence of time-based reserves into operational planning.” Advancing safety “by identifying potential mission points where adequate margin for all foreseeable energy contingencies might be compromised” is the primary goal.
David Dunning, director of global innovation and policy for GAMA, leads the association’s Electric Propulsion and Innovation Committee (EPIC), which wrote the white paper.
“The purpose of energy reserves is to allow continued operations for unexpected situations,” said Dunning in a recent interview with Vertiflite. “How you go about that planning should be tailored to the performance characteristics and mission profile of the [eVTOL and eCTOL] aircraft.”
The current time-based rule, based on conventional fuel and aircraft technology, was incorporated in 1978. An update that considers new technologies, including electric propulsion is needed. Dunning said EPIC recognized some time ago the need to conduct frank conversation with regulators, in parallel with other issues, such as aircraft and pilot certification.
“The parallel issues, such as energy reserves, is something we didn’t want to fall through the cracks,” said Dunning.
Asked if existing regulations should be supplemented with reserve requirements for electric aircraft, Dunning said: “Our goal was not to propose a specific or prescriptive add- on to the regulations. Our goal as an industry is to provide the foundational information needed that the [FAA] and other global authorities can review and make an informed decision that complements existing time-based rules and covers all aircraft types.”
Dunning said these important discussions are needed soon in order to enable the first operations to happen.
Airbus, Beta Technologies, Joby Aviation, Overair, Vertical Aerospace and Volocopter provided input for GAMA’s White Paper.