• 29 Feb 2024 11:37 AM
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TVF 2024 Reaches New Heights

By Dan Gettinger, Managing Editor
Vertiflite, Mar/Apr 2024

More than 600 attendees experienced the latest in VTOL Aeromechanics and Electric VTOL.

On Feb. 6–8, the Vertical Flight Society hosted its Transformative Vertical Flight (TVF) 2024 meeting in Santa Clara, California. Organized in collaboration with the VFS San Francisco Bay Area Chapter (SFBAC), TVF 2024 featured the 11th Annual Electric VTOL Symposium and 6th Decennial VFS Aeromechanics Specialists’ Conference. In addition to the three-day event, Dr. James Wang taught his annual Short Course on Electric VTOL Design on Monday, Feb. 5.

TVF 2024 was an immense success. It featured some 65 technical papers and 70 invited speakers, as well as more than a dozen moderators. The Santa Clara Convention Center also hosted 37 exhibitors. More than 600 people from across the vertical takeoff and landing (VTOL) and advanced air mobility (AAM) spectrum attended TVF 2024.

The following represents a summary of TVF 2024 and excerpts from the wide-ranging discussions that occurred in the invited sessions (the plenary and the Electric VTOL Symposium speakers) of this landmark event. The technical papers, as well as the presentation slides from the invited speakers, were provided to attendees and are available for purchase by others. Visit www.vtol.org/tvf2024 for links to these files and the video recordings of the invited talks.

Plenary Speakers

The first part of the opening plenary session featured presentations by Dr. Noah Schiller, NASA; Arnaud Le Pape of ONERA — The French Aerospace Lab; Dr. Buvana Jayaraman, US Army Combat Capabilities Development Command (DEVCOM) Aviation & Missile Center (AvMC); Dr. Marilena Pavel, Technical University of Delft; Dr. Yasutada Tanabe, Japan Aerospace Exploration Agency (JAXA); and Dr. Håvard Grip of the NASA Jet Propulsion Laboratory. Carl Russell of NASA Ames Research Center, the Aeromechanics Specialists’ Meeting Technical Chair, moderated the session.

Jayaraman discussed the evolution and impact of high-fidelity computational simulations on rotorcraft design. Looking to the future, Jayaraman considered how the Army’s integration of automation and other tools could improve the accuracy and speed of the design process. “A truly integrated and automated physics-based modeling is what we need for the digital transformation of the future,” said Jayaraman. On the issue of automation in high-fidelity simulations, NASA’s Schiller agreed that there was a need for “code algorithm improvements to improve the accuracy and efficiency of flow solvers” and for tools to “automate grid generation” to simplify and accelerate the process.

The second part of the morning’s opening plenary session featured talks by Mark Scott, Science & Technology Corporation; Dr. James Wang, Nanyang Technological University Singapore; Dr. Monica Syal, AIBOT; Dr. Geoffrey Bower, Archer Aviation; and Dr. Gregor Veble Mikić, Joby Aviation. Chris Silva of NASA Ames, Electric VTOL Symposium Chair, moderated the session.

Scott observed that helicopters scale well, noting that the proportions, propulsion and control of an Mi-26 helicopter are all functionally quite similar to that of a remote-controlled (RC) helicopter, despite the former being 10,000 times larger. The simplicity of distributed electric propulsion in small multirotor drones, however, does not scale as well to larger aircraft like certain eVTOL aircraft concepts. Bower also examined the challenges of scale with eVTOL aircraft, observing that for bigger vehicles, the power requirements increase faster than the energy available, meaning that larger vehicles will have shorter endurance. Wang noted that an inability to properly account for the aeromechanical changes in the modified AW609 contributed to the fatal crash of the second prototype in 2015.

At the end of the plenary session, VFS Executive Director Angelo Collins introduced speakers for a special announcement — the new GoAERO challenge. GoAERO CEO Gwen Lighter and NASA Associate Administrator for Aeronautics Bob Pearce announced the launch of the $2M+ GoAERO Prize to design and build a safe, portable, robust, autonomy-enabled emergency response flyer. The GoAERO name includes the acronym for “Aerial Emergency Response Operations.” Learn more at www.goaeroprize.com.

Decennial Aeromechanics Conference

The SFBAC Decennial Aeromechanics conference is held every 10 years, and this year was the 50th Anniversary of the first NASA Ames Research Center/VFS conference held in February 1974. The conference chairs for each of the previous five meetings also gathered at the event. In addition to more than 60 technical papers, six historical presentations were given to document and commemorate the advances in aeromechanics over the past half-century. These presentations were video recorded and will also be made available through the website.

• VTOL Aeromechanics from 1974 to 2024 and the Future — Dynamics
• VTOL Aeromechanics from 1974 to 2024 and the Future — Aerodynamics
• VTOL Aeromechanics from 1974 to 2024 and the Future — Advanced Vertical Flight
• 50 Years of Progress in Rotorcraft Design: A Retrospective from the Vertical Flight Society’s Aircraft Design Technical Committee
• TVF2024: Back to the Future — A Retrospective on the 1974 AHS/NASA-Ames Specialists’ Meeting
• A Brief History of Rotorcraft Aeroacoustics

A group photo was taken of past Aeromechanics Specialists’ Conference chairs, all of whom are current or past NASA or US Army engineers/scientists from the Ames Research Center.

            Seated (L-R):

• Dr. Robert Ormiston — 1974 Technical Chair, 1st Specialists’ Meeting on Rotorcraft Dynamics; and 2024 Co-General Chair, TVF2024
• Dr. Wayne Johnson — Co-General Chair, TVF2024
• Mr. William Bousman — 1984 Technical Chair, 2nd Decennial Specialists’ Meeting on Rotorcraft Dynamics
• Dr. William Warmbrodt — 1994 Technical Chair, Aeromechanics Specialists Conference
• Mr. Tom Maier — 2004 Technical Chair, 4th Decennial Specialists’ Conference on Aeromechanics
  
  Standing (L-R):

• Dr. Buvana Jayaraman — 2022 Technical Chair, Aeromechanics for Advanced Vertical Flight
• Dr. Mark Fulton — 2020 Technical Chair, Aeromechanics for Advanced Vertical Flight
• Dr. Colin Theodore — 2018 Technical Chair, Aeromechanics Design for Transformative Vertical Flight; 2020 General Meeting Chair, TVF 2020; and 2022 General Meeting Chair, TVF 2022
• Dr. Hyeonsoo Yeo — 2014 Technical Chair, 5th Decennial Specialists’ Conference on Aeromechanics
• Mr. Chris Silva — 2024 Technical Chair, 11th Annual Electric VTOL Symposium
• Mr. Carl Russell — 2022 Technical Chair, 9th Annual Electric VTOL Symposium; and 2024 Technical Chair, 6th Decennial Aeromechanics Specialists’ Conference

In addition, a photo was taken of the four TVF 2024 attendees who also attended the first meeting 50 years earlier (L-R): Ormiston, Johnson, Bousman and Prof. Dave Peters, Washington University in St. Louis.

Similar photos were taken at the 5th Decennial Aeromechanics Specialists’ Conference, as published in “Aeromechanics Meeting is a Huge Success,” Vertiflite, March/April 2014.

eVTOL Symposium

The afternoon of the first day of TVF 2024 featured two sessions on eVTOL aircraft, as well as two concurrent sessions on aeromechanics. The first eVTOL session, entitled Vision for the Future, featured presentations by Angelo Collins, VFS Executive Director; Robert M. Pearce, NASA Associate Administrator for Aeronautics; Dr. Brian Yutko, CEO of Wisk Aero; and Dan Newman, new CTO of Honeywell AAM, who also served as the session moderator.

Pearce provided a summary of four key initiatives underway at NASA that are designed to revolutionize aviation. For example, the combination of the Transonic Truss-Braced Wing concept, an ongoing NASA project with Boeing, with other advancements in hybrid-electric propulsion could yield as much as 30% improvements in the efficiency of single-aisle airliners. “That’s a huge leap forward, but that’s the kind we need to be thinking about as we go forward as a cornerstone of our investment,” said Pierce.

Newman discussed a few of the hurdles facing the AAM industry and potential avenues for overcoming them. “Everybody’s got proprietary, but we need some precompetitive, raise-all-boats activities. We can’t just say let ‘NASA do it,’” he argued.

The second eVTOL aircraft panel of the afternoon addressed the progress that several eVTOL original equipment manufacturers (OEMs) had made to date. Moderated by Elan Head of The Air Current, the session featured presentations by Amisha Prakash, Director of Customer Programs, Elroy Air; Martin Peryea, CEO, Jaunt Air Mobility; Craig Smith, Head of Product, Overair; Keisuke Yasukochi, Global Intelligence Officer, SkyDrive; Dr. Han Park, Deputy CTO, Supernal; and Sebastien Vigneron, Senior VP of Engineering, Wisk Aero.

Peryea said that Jaunt Air Mobility is seeking to complete the design of the full-scale, crewed, pre-production test vehicle and begin pre-production aircraft fabrication. Meanwhile, in the months ahead, SkyDrive, which is preparing to launch air taxi services with its eVTOL aircraft at the 2025 World Expo in Osaka, Japan, will conduct a series of educational sessions with various stakeholders in the region to improve public acceptance and familiarity with eVTOL aircraft, said Yasukochi. This year, Supernal is planning to begin test flights of its full-scale S-A2 eVTOL aircraft prototype and submit applications for the certification of its vehicle. “2024 is going to be a really busy year for us,” said Park of Supernal.

The second day of TVF 2024, Feb. 7, featured seven sessions on eVTOL aircraft — three in the morning and four in the afternoon — as well as four sessions on aeromechanics. The first eVTOL session addressed AAM perspectives and featured presentations by Dr. Sergio Cecutta, SMG Consulting; Willi Tacke, Flying Pages; Pamir Sevincel, Blackbird; and a joint presentation by Gwen Lighter, GoAERO, and Dr. Sky Sartorius, Boeing. Mike Hirschberg of VFS moderated the session.

Cecutta highlighted the fact that fixed-base operators (FBOs) could provide an interim or long-term solution to the absence of infrastructure for eVTOL aircraft at airports. Willi Tacke said that he expects the first operations involving eVTOL aircraft could occur in Shenzhen, China, due to the combination of government support and the availability of infrastructure.

Sevincel’s talk was titled, “Vectored-Thrust: The Dominant Design for eVTOL v1.0?” He noted, “The important part is that, as an ecosystem, the design choices we make today… is going to shape what the eVTOL industry will be like decades ahead.” Lighter and Sartorius outlined the details of the GoAERO competition rules, highlighting that they were looking for feedback on the challenging demonstration requirements.

Electric propulsion was the subject of the second eVTOL session of the morning. Moderated by Luigi Ricci Moretti, the session featured presentations by Dr. Jaydip Das, Carpenter Electrification; Dr. Krista Tweed, Hottinger Brüel & Kjær; and Eric Bartsch, VerdeGo Aero.

Tweed discussed a few of the challenges that arise from new propulsion technology on eVTOL aircraft, such as the effects of vibration, the presence of many motors on each air vehicle and the use of high voltages. “As with any system, there are a variety of thermal, mechanical and electrical failures that can happen,” said Tweed, underscoring the need for testing to understand system behavior.

Bartsch took the opportunity offered by TVF to discuss publicly for the first time the VH-4T turbine hybrid system, the third hybrid powerplant architecture product offered by VerdeGo Aero. “The transformation revolutionary technology is often not the battery, it’s the electric motor,” argued Bartsch. Military missions are driving a lot of the adoption of hybrid electric powerplants, he said.

The third session of Symposium’s second day addressed hydrogen-electric propulsion. Chaired by Luigi Ricci Moretti, the session featured presentations by Danielle McLean, CEO of HYSKY Society; John Piasecki, CEO of Piasecki Aircraft Corp.; and Bill Spellane, COO of Alaka’i Technologies.

McLean outlined how the educational non-profit was spun out of the Vertical Flight Society’s H2eVTOL Council, and how the Department of Energy was investing heavily in hydrogen hubs across the US (see “Hydrogen Gains Ground,” Vertiflite, Nov/Dec 2023).

Piasecki Aircraft is planning to begin ground testing its Hydrogen coAXial Electric Lift (HAXEL) in August, with the first flights — potentially the first hydrogen-powered flights of its kind — scheduled to begin this fall. HAXEL, said Piasecki, will inform the development of the full-scale 885-shp (660-kW) hydrogen fuel cell test stand. Piasecki will use the test stand to validate the performance, reliability and safety of hydrogen-powered helicopters, namely its PA-890 High Temperature Proton Exchange Membrane (HTPEM) hydrogen fuel cell-powered helicopter.

Alaka’i Technologies, meanwhile, is developing a multi-rotor, hydrogen-powered aircraft for inter-city transportation. The company has built two full-scale demonstrator aircraft that it flies “almost every day,” Spellane said. Both generations of demonstrators are designed to easily accommodate new components and technologies, a reflection of the ongoing advances in areas such as lightweight hydrogen fuel cells and electric powertrains.

“We already fly at the MTOW [maximum takeoff weight] that we intend to sell this into market, so it’s a matter of executing on the engineering challenges and the certification challenges,” Spellane said. The company is at “about stage 3” of an accepted FAA G-1 Certification Basis, and is working with the FAA on the G-2 Means of Compliance.

The first afternoon eVTOL session on Feb. 7 addressed personal eVTOL aircraft. Moderated by Andy Mearns of Multicopter Aerospace Consulting, the session included presentations by Ken Karklin, CEO, Pivotal; Chen Rosen, CTO, AIR EV; and Dr. Carl Dietrich, CEO, Jump Aero.

In the last year, Pivotal has trained more than a dozen new pilots to test fly its BlackFly / Helix ultralight demonstrator, said Karklin. Although Pivotal is primarily aiming for private customers, the company imagines its aircraft could have defense applications, potentially as an uncrewed vehicle for cargo delivery or medical evacuation. The company is also exploring two-seat versions.

AIR, meanwhile, was pleased by the introduction in July 2023 of the US Federal Aviation Administration’s (FAA’s) proposed Modernization of Special Airworthiness Certification (MOSAIC) regulatory framework for light sport aircraft (see “Washington Report,” Vertiflite, March/April 2024), which it thinks could propose another pathway to offer its AIR ONE aircraft to the public. Still, said Rosen, the public’s response to MOSAIC has illustrated a lingering misperception of eVTOL aircraft and the AAM industry. Despite the wide variety of eVTOL aircraft concepts currently in development, “there is a view of the entire eVTOL ecosystem as a very homogenic thing,” said Rosen, advocating that simple personal eVTOL aircraft should be treated separately from more sophisticated air taxis.

Session seven, the second eVTOL session of the afternoon, focused on AAM missions and was moderated by Elan Head. It featured presentations by Dr. Parimal Kopardekar, NASA; Chris Silva, NASA; and Jim Sherman, AIAA.

“We really would like to accommodate the growing aviation need without overloading the air traffic control system,” said Parimal Kopardekar. NASA is exploring how third-party services and applications, which began with integrating small drones into the airspace, could offer part of the solution for future AAM needs, such as weather and 3-D mapping. NASA has sunset its Advanced Air Mobility National Campaign (see “NASA’s National Campaign,” Vertiflite, May/June 2020); going forward, NASA’s AAM efforts will be devoted to “technology capability level demonstrations of key concepts and key ideas and technologies,” said Kopardekar.

The second day of TVF closed with a session on uncrewed VTOL aircraft and another on military applications. Pamir Sevincel moderated the former, session eight, which featured presentations by Dr. Hector Xu, CEO of Rotor; Manal Habib, CEO of MightyFly; and Johnny Doo, President of International Vehicle Research. Session nine was moderated by Angelo Collins and featured Lt. Col. John “Wasp” Tekell, Air Force AFWERX Agility Prime, and Mitchell Burnside Clapp of DARPA’s Tactical Technology Office.

The third day of TVF 2024 featured six sessions on eVTOL aircraft, as well as four sessions on aeromechanics. The morning of Feb. 8 opened with a session on eVTOL design and manufacturing. Luigi Ricci Moretti moderated session 10, which featured presentations by Thomas Nascenzi, M4 Engineering; Dr. Bob Yancy, Hexcel; Stacy Biel, Toray; and Joe Meyer, RE:Build Manufacturing.

Yancy observed that, should the AAM industry prove successful, it will see higher aircraft build rates — perhaps hundreds of aircraft per month — than other sectors of the aviation industry. “This industry will present some unique challenges to material suppliers,” said Yancy. “But I’m hoping that this industry will help propel some real advances in manufacturing and material development that will benefit not only this industry but other industries as well.” In expectation of higher build rates, Toray’s customers, said Stacy Biel, are interested in looking at means of high-volume production and ways of taking “today’s materials or next-generation materials and process them in a quicker fashion.”

Meyer presented an overview of RE:Build Manufacturing, a family of industrial businesses “combining cutting-edge enabling technologies, operational superiority and strategic [mergers and acquisitions] to build America’s next-generation industrial company.” Its goal is to help revitalize the US manufacturing base over the coming decades, “creating substantial opportunities for our employees and the communities where we operate.”

The eVTOL session 11 addressed standards and certification. Moderated by Mike Hirschberg, it featured presentations by Dave Franks, SAE International; Ryan Naru, Joby Aviation; Chip Palombini, Beta Technologies; Dr. Mike Romanowski, Archer Aviation; Chris Courtney, CAE; and Anna Dietrich, Anna Dietrich Consulting.

Franks described the many relevant SAE committees working to develop standards for the AAM industry and invited experts to join the committees to help shape the future. Naru and Palombini discussed their electric aircraft charging systems (see “Competing Standards,” Vertiflite, Jan/Feb 2024), while Dietrich gave an overview of some of the opportunities and challenges of the proposed MOSAIC rules and other regulations.

The AAM industry will need to develop consensus standards on topics like autonomy, infrastructure, operational factors, safety, simulators, and so on, said Archer’s Romanowski. “As much work as there is going to be for us in the industry, private sector and academic community to come together around those standards, the workload on the agencies is going to be significant because they’re going to have to evaluate those standards,” he said.

The afternoon of Feb. 8 opened with eVTOL session 12, which addressed regulations. The session featured presentations by Shawn Kozica, FAA Office of NextGen; Ludovic Aron, the European Union Aviation Safety Agency (EASA) Representative to the US; and Tom Gunnarson, Lead of Regulatory Affairs at Wisk, who also moderated the session.

The FAA is on target to publish the Special Federal Aviation Regulation (SFAR) for powered-lift aircraft in the fall of 2024. “We know that [the SFAR] is a definite area of importance to [the industry], so we’re working pretty hard on that,” said Kozica. Late this year, the FAA expects to update “EB 105, Vertiport Design,” which it initially published in September 2022; the Advisory Circular on vertiport design is expected in 2025. The Department of Transportation also expects to publish the joint AAM Interagency Working Group (IWG) National Strategy Report. The FAA is also seeking to expand its outreach on AAM with local communities by working with its regional teams around the country. “We need our regional teams to be engaged sooner than they usually would in implementing a specific operation,” said Kozica.

Insurance and telematics were the subjects of eVTOL session 13, which was moderated by Andy Mearns. It featured presentations by Connor Haarhuis, Global Aerospace; Danny Maco, AeroTelematics; Scott Gault, Newfront Insurance; and Alistair Blundy, Skyrisks.

Telematics, the practice by automotive insurance providers of collecting data on individual driving habits in exchange for potentially discounted premiums, could be an opportunity for those in the AAM industry, particularly for the manufacturers of personal eVTOL aircraft, explained Maco. “The easier you make it for your customers to buy insurance, the easier they are to make a decision on buying an aircraft,” said Maco. The potential benefits of applying this approach to those in the commercial AAM space could be even greater than it has been for fleets of commercial ground vehicles, he said.

Bristow, the “world’s leading provider of vertical flight solutions to customers and governments worldwide,” has partnered with eight different AAM companies to provide critical safety, operational, certification and logistics expertise to guide the launch of eVTOL and other AAM services. The company intends “to diversify our fleet and service offerings by utilizing multiple AAM aircraft to build robust network capabilities and support various end markets.”

Session 14 featured a panel discussion on autonomous infrastructure and operations, and covered the gamut of considerations for smart infrastructure, including artificial intelligence (AI) and Machine Learning (ML), sensors, communications, blockchain, security and noise perception. Moderated by Jim Sherman, the panel featured Mike DiCosola, CEO of Drone Industry Systems Corp. (DISC) and Vertiport Infrastructure Systems Corp. (VISC); Prof. Jasenka Rakas of the University of California, Berkeley, and Deputy Director of the FAA’s NEXTOR Center of Excellence; Virginia Stouffer, President of Transformational Technologies LLC; Ken Freeman, a secure airspace project engineer at NASA Ames; and Andy Christian, a psychoacoustics research engineer at NASA.

The final eVTOL aircraft session of TVF 2024 addressed challenges and opportunities. Moderated by Ken Swartz of Aeromedia Consultants, the session featured presentations by Mandy Nelson, Director of Strategic Relationships for AAM, Bristow; Kuljeet Sandhu, CEO, Nalwa Aero Pvt Ltd.; and Peter Jesson, Lead Customer Project Engineer for UAM, Rolls-Royce Electrical.

Nalwa Aero is developing India’s first five-seat eVTOL aircraft. The Nalwa 5x has 12 tilting electric ducted fans (EDFs), each powered by an electric motor. The EDFs are mounted on the canard and the rear box wing. The motors are powered by a hydrogen fuel cell and lithium batteries. Rolls-Royce Electrical (previously part of Siemens, see “Rolls-Royce Retrenches,” Vertiflite, Mar/Apr 2024) develops electric propulsion units and electric distribution systems that are compatible with battery, hydrogen fuel cell, turbogenerator and other systems.

TVF 2025

VFS will hold Transformative Vertical Flight 2025 on Feb. 4–6 in Phoenix, Arizona. It will feature the 11th Biennial Autonomous VTOL Technical Meeting and the 12th Annual Electric VTOL Symposium. Details are posted at www.vtol.org/tvf2025. The call for papers will be posted in May. Plan to attend!