Meet the eVTOL Flight Test Council
Anyone associated with SFTE...
... knows it is a typical professional society in many ways. It provides venues for practitioners to share experiences, publish papers, and network. Extending beyond typical, our society also boasts a long history of promoting professional development. SFTE historically accomplished this through numerous Technical Council initiatives and more recently by standing up a new Flight Test Training & Education Committee. Being an inclusive organization casting a broad net, SFTE also sponsors an independent council focused on flight testing two nascent technologies: electric power and novel VTOL configurations. Let’s meet that council...Backstory
Until around 2019, most Vertical TakeOff and Landing aircraft (condensed to ‘verticraft’) were either large, complex turbine-powered machines or small hobby-size drones. A few medium-size drones and fewer occupied verticraft had begun flying, but there had been effectively no collaboration among their testers. One reason was startup manufacturers having little background in flight test (FT) and not knowing about organizations like SFTE. Another reason was that although SFTE and others welcomed technical presentations and papers, there was a recruiting void.As Technical Council Chair at that time, SFTE Fellow Al Lawless saw the dearth of participation among eVTOL testers. He determined there was in fact a strong desire to collaborate towards developing FT practices for these novel machines. With no such venue existing but with encouragement from industry and regulators alike, Al launched one. Originally scoped just for eVTOL aircraft, charter members quickly expanded to embrace test all types of electric and hybrid-electric aircraft, including airplanes and rotorcraft. Kicked off in July 2020, they became the E-VTOL Flight Test Council.
Charter
The council’s mission is to Promote flight test safety, efficiency, and knowledge for electric and verticraft development, certification, and qualification. Deliberations cover all configurations, sizes, classes, payload/passenger combinations, and piloting options. https://www.sfte.org/e-vtol_council.phpThe E-VTOL FTC is an independent volunteer group that enjoys support from multiple sponsors including SFTE and the Vertical Flight Society (VFS). The council has no dues or membership requirements and encourages its members to publish with their professional society of choice. VFS sponsors the council via hosting virtual meetings and its ever-expanding library. Furthermore, VFS graciously provides access to council members who are not VFS members. SFTE also readily supports the E-VTOL FTC upon request - including advertising routine and special events.
Typical Meetings
The E-VTOL FTC held its first 100 meetings bi-weekly; there was so much novelty and churn that a lower frequency could not meet demand. Everyone had questions across the FT spectrum. Some members were entirely new to the profession while others knew traditional FT but wanted to know the ‘deltas’ appropriate for verticraft and for electric aircraft. Meetings developed a four-part rhythm beginning with general updates. This covers news within the council’s niche, including relevant press releases and publication announcements. Part two updates recurring topics such as additions to the council’s digital library, internal and external events, and liaisons. Liaisons are members tied to other organizations whose interests overlap the council’s. Completing part two is a paper review. Each meeting has a young, hard-charging FTE reviewing relevant technical papers and selecting one for spotlighting with a synopsis.The E-VTOL FTC’s second and third focus groups closed after meeting their deliverable goals. The Handling Qualities Advisory Committee provided an open venue to develop means for showing verticraft compliance with certification rules. With regulator participation throughout, the committee’s final report in May, 2024 recommended an approach and lexicon that could equally accommodate aircraft with a pilot in or out of the control loop. The Human Machine Interface Committee formed to bring human factors experts and flight testers together for the ambitious goal of developing process to certify the coming generation of verticraft and remote ground control stations. After two years, this effort descoped to providing a compilation of synopses of guidance material, delivered in July 2024.
Part three is committee chair briefings on recent deliberations and accomplishments. These focus groups formed naturally upon recognizing specific and recurring interests among some members. All share the council’s mission to develop and promote best practices for flight testers. First to launch was the Electric FT Committee. The fourth was the Automated Flying Qualities Committee which focuses on ensuring acceptable flight characteristics wholly-automated aircraft (i.e., no modulation inceptors or other provisions for pilot-in-the-loop control). Both committees remain active.
The climax of most meetings is the featured topic. Members or guest speakers cover the spectrum within the council’s wheelhouse, including pilot qualification, aerodynamic modeling, downwash/outwash, human factors, tech techniques, safety, and so much more. Guest speakers include researchers from NASA and Canada’s NRC, the FAA, EASA, academia, and of course flight testers sharing lessons. Some topics are extensive enough to own the entire meeting. Some features are encore presentations published elsewhere. The council’s library (within the VFS Hover page) posts all session recordings and meeting reports, so members can review them anytime.
Accomplishments
Some tangible products include council member papers published by SFTE:- Things Flight Testers Should Know About Batteries for Electric Propulsion
- Things Flight Testers Should Know About Electric Engines
- Things Flight Testers Should Know About Hydrogen (a spin-off inspired by the above)
- VTOL Taxonomy and Lexicon
- Verticraft Flight Test Challenges
Other products include advisory reports, comments to regulators, and even magazine articles.
- VTOL Handling Qualities Committee Final Report: HQ Criteria Recommendations
- Formal comments to proposed PS-AIR 21.17-02 Special Class Rotorcraft
- Formal comments to proposed AC 21.17-4 Type Certification—Powered-lift
- Compilation of Human Factors guidance for flight testers
- A detailed outline of a Full Spectrum Concept for Assessing Human Machine Interface.
- Numerous Vertiflite installments addressing VTOL taxonomy and certification challenges
When specific topics extend beyond its members’ interests, the council works with experts and societies to advertise and produce workshop videos and post them on the VFS website and YouTube.
^ Aviation Battery Performance Modeling ^ eVTOL Certification 101
^ Managing Range and Endurance of Battery Electric Aircraft ^ VTOL Taxonomy and Lexicon
^ Outwash Characteristics of VTOL Aircraft ^ Vortex Ring State for VTOL Aircraft
^ Things Startups Should Know About Certification Flight Test ^Simplified Vehicle Operations (SVO)
^ Systems Theory Process Analysis (STPA) for Flight Testers ^ How X Plane can be used for eVTOL
A less tangible accomplishment comes from understanding that in 2020, regulators only had raw ideas of what would be needed to certify. By participating in our conversations, authorities could informally hear members’ questions and concerns – something that would naturally influence their thinking. In turn, regulators could help guide conversations (again informally) to what they expected would be acceptable approaches. Years of authority participation and positive feedback places the ‘soft influence’ of regular meetings among the council’s enduring accomplishments.
Going Forward..
In 2025, the E-VTOL FTC slowed its pace to monthly meetings because the fog lifted on many previously nebulous matters. Authorities have more clarity on how to proceed and the nascent verticraft industry has begun its expected consolidation. Nevertheless, numerous technical topics remain wide open for discussion and more research data is rolling in. The council will continue its routine and keep pace – as will its subcommittees. The Electric FT Committee meets monthly, with more focus on hybrid electric aircraft. The AFQ Committee will publish its first a technical paper in 2025. Included will be a “Call to Arms” to bring more research into critical areas.For more information, contact the council chair at sfte@alawless.com.
All are welcome to join virtual E-VTOL FTC meetings on any first Tuesday, 11-noon Eastern time.
Zoom Meeting ID: 945 3932 7683, Passcode: 829514 or
https://zoom.us/j/94539327683?pwd=RTNqVzlQSE1TcXFWSjYxazBvazdiUT09