Whether it’s a short jaunt or a longer journey, one eVTOL start-up is taking the road less traveled to make vertical flight more accessible to the common man.
For nearly a century, civil vertical flight has been nearly exclusively the domain of helicopters or gyroplanes suspended beneath a single, large, spinning overhead rotor. However, experts have long known that a “lift-compound” rotorcraft (i.e. with a wing) could achieve greater cruise speeds and efficiency than a traditional helicopter if the rotor was slowed to reduce drag during wingborne flight, but there were many technical and other challenges to overcome.
Jaunt Air Mobility was created in 2019 to bring the world’s first electric Slowed Rotor Compound (SRC) aircraft to market, leveraging recent advances in electric motors and controllers, lithium-ion batteries and fly-by-wire flight controls to overcome some of these challenges. Jaunt acquired the intellectual property of Carter Aviation Technologies, which had spent 25 years refining all the systems and components required to operate as a high-speed and energy-efficient compound helicopter, part airplane and part helicopter — which Jaunt says is the most efficient electric vertical takeoff and landing (eVTOL) configuration.
Jaunt’s five-seat Journey compound rotorcraft might not look as futuristic as an eVTOL aircraft with tilting wings, tilting propellers or multiple thrusters to transition from vertical to forward flight, but simplicity has its own elegance.
The Journey is designed to achieve fast and efficient high-speed flight, and to safely manage a loss of power using the wings and the stored energy of the high inertia/low disk-loading rotor to safely autorotate like a helicopter or glide like a fixed-wing aircraft to the ground in a controlled manner if it loses power at any speed or altitude.
From a certification perspective, Jaunt is the only company today that has declared that its eVTOL aircraft is being specifically designed to meet existing US Federal Aviation Administration (FAA) FAR 29 transport category rotorcraft rules; it will also have Category A (CAT A) multi-engine performance in the event that an electric motor or propeller fails.
Jaunt believes the combination of good aircraft design and rigorous certification testing will make the Journey, “the safest, quietest, and operationally efficient all-electric air taxi.” This is a bold claim — until you understand the aircraft and the company.
Since 1994, Jay Carter, Jr. had designed, built and test flown four different SRC technology demonstrator gyrocopters that coupled the speed, range and efficiency of an airplane with the runway independence of a helicopter (see “Modern Day Autogyros: Back to the Future,” Vertiflite, Fall 2003). Together, Carter’s SRC flight demonstrators have logged 300 piloted hours.
However, Carter’s deal to bring an electric SRC aircraft to market suffered a major setback when Mooney’s CEO retired and the Chinese owner dropped out of the Uber program. Convinced that electric SRC technology had a future, Carter and its supporters, such as Georgia Tech’s Dr. Daniel P. Schrage, started searching for a new business partner.
Jaunt Air Mobility
At the Vertical Flight Society’s 6th Annual Electric VTOL Symposium in Mesa, Arizona, in January 2019, VFS announced that Jaunt Air Mobility had acquired the rights to Carter’s SRC design, including its eVTOL air taxi work.
The start-up was co-founded by entrepreneur Kaydon Stanzione, an engineer and former Pentagon advisor (and prior Membership Chair on the VFS Board of Directors), and Martin Peryea, a well-respected senior rotorcraft engineer, executive and technologist. Stanzione was familiar with the technology through VFS affiliations and research he had conducted on SRC technology for the US Special Operations Forces, and was re-introduced to Carter at the VFS Forum 74 in May 2018.
Peryea worked for Bell Helicopter for 33 years, rising through the engineering organization to become VP of Commercial Engineering, chief engineer for Bell’s US government programs and the fly-by-wire super medium Model 525 Relentless, and a highly regarded Bell Technical Fellow. In 2016, he left Bell to become VP of Engineering at Triumph Aerospace Structures (sold earlier this year to Arlington Capital Partners and renamed Qarbon Aerospace).
In 2010, Peryea had participated in a critical design review of Carter’s four-seat Personal Air Vehicle (PAV), after AAI Corporation signed a licensing agreement in 2009 to use the PAV as a platform for a vertical takeoff, high-speed, long-range unmanned aircraft system (UAS). AAI (since absorbed into Textron Systems) was a subsidiary of Bell-parent Textron, and Bell engineers supported AAI for this effort.
When Uber launched the Elevate project, Peryea met with many eVTOL developers, including Carter, to understand how Triumph could play a role in the emerging industry. Peryea left Triumph to become Jaunt’s chief technical officer (CTO) in April 2019, and two months later, Uber announced on the opening day of the third Elevate Summit in Washington, DC, that the Jaunt Journey SRC was the sixth aircraft being developed for Elevate.
The first Elevate Summit played a significant role in mobilizing global interest and investment in eVTOL technology and the air mobility ecosystem, and Jaunt immediately benefited from Uber’s market insights, which established very specific performance, noise, economic and passenger experience targets.
Uber only selected vehicle partners that were developing all-electric VTOL aircraft with wings, which is the most energy-efficient means of achieving high cruise speeds. Jaunt found itself in good company as Uber vetted scores of companies and designs, but only selected eight companies as vehicle partners — Aurora Flight Sciences (now part of Boeing), Bell, Embraer, Hyundai, Joby, Overair (a spinoff of Karem Aircraft), Pipistrel and Jaunt — with only Jaunt developing a rotorcraft with a single-main rotor.
Carter Aviation Technologies
Since its inception in 1994, Carter Aviation Technologies has been granted multiple patents for SRC aircraft and related technology.
Much has been written about Carter’s quest to achieve a high Mu ratio (the ratio of airspeed to rotor tip speed), which he saw as essential to achieve high-speed, long-range rotary-wing flight (see “Carter’s Slowed-Rotor/Compound: Putting a New Spin on an Old Concept," Vertiflite, March/April 2013).
His first prototype was the CarterCopter Technology Demonstrator (CCTD) autogyro (N121CC), first flown on Sept. 23, 1998, which had a max takeoff weight (MTOW) of 4,200 lb (1,900 kg). The futuristic CCTD had a five-place, pressurized, largely composite cabin, a 32-ft (9.8-m) diameter unpowered rotor, a 32-ft span wing, twin tail and an 8-ft (2.4-m) variable pitch pusher propeller powered by a 325-hp (242-kW) Chevrolet Corvette LS-6 engine.
Carter's main focus was researching stability in high-speed flight, so the demonstrators were kept less complex by achieving vertical flight with a jump takeoff. The stiff, high-inertia rotor was powered on the ground to a high rotational speed of 365–425 RPM to achieve a jump takeoff. The propeller then increased pitch for forward flight and the rotor was unpowered, initially driven by inertia, transitioning to autorotation as the air passed through it. The aircraft gradually transitioned to wingborne flight, which was complete by about 125 mph (200 km/h).
The CCTD was partially funded by NASA research grants and private investors, and achieved its maximum Mu of 1.0 on June 17, 2005, but was permanently grounded after a hard landing.
The Carter PAV autogyro was the company’s second-generation technology demonstrator, initially with a MTOW of 3,800 lb (1,724 kg). The PAV featured a four-seat cabin, 45-ft (13.7-m) diameter rotor and wing, and a conventional 250–350 hp Lycoming TIO-540 piston engine driving a 78-inch, (2-m) pusher propeller.
The PAV prototype (N110AV) first flew without wings in Olney, Texas, in January 2011, and with wings attached a year later. The second PAV (N210AV) made its first flight in 2014.
In 2014, Jay Carter, Jr. received the VFS Paul E. Haueter Award for an outstanding technical contribution to the field of vertical takeoff and landing aircraft development other than a helicopter. The Carter PAV ultimately achieved flights at advanced Mu ratios as high as 1.16, an altitude of almost 18,000 ft (5,500 m), a level flight true airspeed of 214 mph (344 km/h), varying rotor speed down to 100 RPM, and a flight of more than one hour.
Illustrations of the 2017 Mooney/Carter SRC electric air taxi depict a sleek rotorcraft with a two-bladed main rotor, low wing with a swivelling thruster mounted on the tail for anti-torque control and forward thrust.
The Jaunt Journey SRC design has some resemblance, but now has a high wing and four wing-mounted propellers for anti-torque. Independent, redundant electric motors power the main rotor for vertical flight and hover.
The main rotor RPM (and power) gradually decreases as the aircraft accelerates and the wings begin to provide lift. In cruise, the rotor is nearly unloaded but still rotating at its optimum speed to minimize total aircraft power consumption and maintain rotor stability. Since rotor rotational drag increases with the cube of RPM, when the RPM is reduced by a third, the rotor will generate 4% of the rotational drag and 18% of the total rotor drag compared to flight at full RPM.
The Journey is designed to safely, efficiently and quietly fly a pilot and four passengers, with a range of 80–120 miles (130–190 km), cruise at speeds up to 175 mph (280 km/h), and have a noise signature of 55 dB in cruise and 69 dB during takeoff and landing (compared to 85 dB and 90 dB, respectively, for a similarly sized helicopter).
One benefit of acquiring Carter’s SRC technology is that the Journey can use a similar rotor and rotorhead to the one Carter developed. The rotor head features a flexible-beam assembly for collective pitch control and a tilting hub in lieu of cyclic control.
To achieve optimum speed, the Jaunt Journey reduces RPM and unloads the rotor in wingborne flight to reduce power, vibration, loads and noise. Carter progressively refined his rotor design by adding heavy tungsten tip weights ahead of the blade center of pressure (the quarter-chord line), forcing a large forward center of gravity while keeping the center of lift near the quarter-chord line.
The weights provide high rotational energy storage and stability in high-speed flight. All rotorcraft blades use tip weights in the leading edge for stability, but since the retreating blade on the Jaunt Journey is in reverse flow, the loss of stability is overcome by adding additional weight, which improves the advancing blade stability and the entire rotor system stability.
Historically, the major technological barrier to introducing SRC technology on a helicopter had been the lack of a certified direct drive aircraft engine or multi-speed gearbox that could cover the wide RPM range. Carter foresaw the benefits of electric aircraft propulsion a decade ago when he filed a patent in November 2011 for a “Power Rotor Drive for Slowed Rotor Wing Aircraft” that used an electric motor or a variable speed transmission. This was followed in April 2012 with a patent application for an “Electric Motor Powered Rotor Drive for Slowed Rotor Winged Aircraft.”
Jaunt has also signed a partnership with VerdeGo Aero (see “Hard-Core Hybrids,” Vertiflite, May/June 2021), which is developing a family of hybrid-electric engines that could provide the aircraft with extended range or the ability to fly in regions with no electric charging infrastructure.
The wing design is similar to the high-lift wing of a glider and optimized for cruise flight rather than takeoffs and landings. According to a patent application filed by Carter, Jeffrey R. Lewis and Peryea, published in November 2019, one of the benefits of placing propellers at the wing tips is “to reduce the wing tip vortex and induced drag.”
The primary role of the tilting mast on the Journey is to maintain an optimum pitch of the wings and the fuselage, providing the pilot with good forward visibility, keeping the cabin level for passengers, and providing the aircraft with a wide center of gravity when loading passengers or cargo. Ride quality is further enhanced by the mast’s flexible supports, which are designed to isolate rotor loads from the passenger cabin.
Jaunt is raising funds to advance its design and develop a full-scale flight demonstrator aircraft and supporting infrastructure. The timeline calls for the first flight of the preproduction Journey in 2023, low-rate production in 2025 and certification in 2025-2026.
The company’s management team has extensive experience in aircraft design, validation, test, certification and commercialization of aircraft.
The company’s senior leadership now includes Jesse Crispino, Chief Operating Officer; Dr. Simon Briceno, Chief Commercial Officer; Dr. Chittur (Venkat) Venkatasubban, Chief Engineering Fellow (Flight Technology); Dr. Sanjay Gattani, Chief Engineer Aircraft Certification; Jeff Lewis, Senior Engineer; Robert Pratt, Program Manager; and Nancy Richardson, Chief Communication Officer.
Crispino was previously the director of the Systems Integration Management Office for the 160th Special Operations Aviation Regiment, US Army Special Operations Aviation Command. He’s an Army experimental test pilot (fixed- and rotary-wing) with certification experience on six Army aircraft.
Briceno was a member of the research faculty and head of the Transformative Aviation Concepts Division in the Aerospace Department at Georgia Tech. He conducted several landmark studies on AAM with NASA and led aviation safety programs with the FAA.
Venkatasubban has 40 years of experience in senior positions leading engineering teams in the aerospace industry at companies such as Cirrus Aircraft, Bombardier Aerospace, Raytheon Aircraft, Hawker-Beechcraft, Bell and Terrafugia.
In September 2020, Peryea became CEO of Jaunt as a new round of fundraising began.
Collaborative Industry Relationships
Many of the companies selected to be Uber Elevate partners have gone out of their way to highlight how vertically integrated they are as a company, as far as designing, building and operating their eVTOL aircraft.
Jaunt is taking a more traditional aerospace industry approach that leverages agreements with Tier 1 aerospace systems integrators for technical and cost risk reduction. In the past two years, Jaunt has established collaborations with key industry participants, two of whom have been named: BAE Systems and CAE.
Peryea says one of the attractions for Tier 1 companies is the high production volumes the advanced air mobility (AAM) market is expected to generate. This provides an opportunity to recover non-recurring engineering costs in a much shorter period than for traditional commercial and business aviation aircraft or helicopters. And there is also an opportunity to apply systems and manufacturing processes developed for eVTOL aircraft to other products sooner than would traditionally be possible with low-rate production programs.
Jaunt believes that vertically integrated eVTOL developers will be challenged to master all the technologies integrated into their aircraft, and regulators will be very cautious certifying mission-critical systems developed by companies they have never worked with before.
In December 2019, Jaunt announced it was partnering with BAE Systems to provide the battery energy management system, high voltage power distribution and flight control computers for the Journey.
The flight control system resembles that of the Bell 525, for which BAE developed the fly-by-wire flight controls when Peryea was the aircraft’s chief engineer. In the cockpit, the controls have been designed for simplified vehicle operations (SVO). The pedals control the yaw axis through actuation of the rudder and differential propeller thrust. Like a helicopter, the left stick controls the vertical axis via main rotor blade pitch. The right stick controls the longitudinal axis — through longitudinal hub tilt, mast angle tilt and the elevator — and the lateral axis — including lateral rate, lateral speed, and position hold — through lateral hub tilt and aileron deflection.
Jaunt says the flight control system employs a traditional back-driven, force-feedback stick trim management system to provide the pilot with full awareness of the remaining control margin by providing a displacement trim. It also provides automatic entry into autorotation in the event of total electric propulsion loss — the control laws manage blade and mast tilt to maintain RPM and establish the aircraft for steady state autorotative flight.
Other design features include CAT A performance to overcome a failed motor condition (like a “one engine inoperative” or OEI); the control laws will automatically adjust the power on the remaining motors to compensate, and performance is enhanced by tactile limit cueing for the collective stick during CAT A takeoff and landing. The Journey will also use automatic mode switching between all flight modes and transition between various states (as determined by speed or altitude), without needing any mode switches.
BAE Systems also has 20-plus years of experience developing and integrating electric propulsion systems, which in the case of the Journey will include multiple electric motors powering the rotor and the propellers.
“We are leveraging decades of experience in flight controls and energy management systems to develop solutions that will enable the next generation of flight,” said Ehtisham Siddiqui, VP and General Manager of Controls and Avionics Solutions at BAE Systems. “We are continually advancing the state of the art in high-integrity energy systems, specifically battery technologies, and have validated that our designs will meet the requirements for advanced air mobility aircraft. We are proud to bring a holistic, integrated approach to controls and power management for Jaunt.”
In May, Crane Aerospace & Electronics announced that it was collaborating with BAE to provide specific expertise on the power management systems for Jaunt. Crane will conduct a series of studies to explore the exact power needs to determine an optimum power electronics solution for the Journey.
Uber established very specific direct operating cost (DOC) targets for each of its air vehicle partners.
Jaunt says the Journey will cost about 44% less to operate than a similar-size light turbine helicopter (like the Bell 505) on a flight hour basis, with most of the savings resulting from lower energy and maintenance costs — even including battery replacement costs.
The company believes the Journey’s performance and economics will make it very competitive for a number of AAM missions (e.g. urban air taxi, airport shuttle, middle-mile freight), as well as a replacement for helicopters used for air ambulance, search and rescue, law enforcement and humanitarian relief missions.
Jaunt says the Journey will be among the quietest VTOL aircraft — helicopter or eVTOL — flying in tomorrow’s skies.
The primary reason is that the aircraft’s main rotor is significantly larger than the two-bladed rotors on similar capacity helicopters, such as the Bell 206B and Robinson R66 — which are both 33-ft (10.1-m) in diameter — resulting in lower blade loading and a much slower RPM.
Jaunt believes this will make the Journey 100 times quieter (a 20 dB reduction in noise) than similar weight helicopters during takeoff, landing and overflight.
In 2019, Jaunt began formulating a strategy to move the majority of the company’s design, manufacturing and aircraft certification activities to Canada.
This was influenced by Peryea’s long association with the Canadian aerospace industry and Transport Canada Civil Aviation (TCCA), which began 35 years ago when Bell opened its factory at Mirabel, north of Montreal, and transitioned all its commercial helicopter production and certification activities to Canada over the next four years.
The favorable impressions were further reinforced when Triumph was contracted to build the high-speed wing for Bombardier’s flagship Global 7500 business jet (Bombardier later bought the wing factory from Triumph).
Transport Canada is also highly regarded when it comes to commercial aircraft certification. In fact, the centralized aircraft certification office in Ottawa probably has more experience certifying commercial rotorcraft than any regional FAA office on its own, with this especially true when considering all the new helicopters certified or upgraded in Canada by Bell. In addition, TCCA is responsible for all new helicopter models certified by the FAA and the European Union Aviation Safety Agency (EASA) that are introduced to Canada, which is the world’s second-largest civil rotorcraft market.
Peryea also considered Quebec a very favorable business site since the province is very supportive of aerospace innovation and many world-leading, locally-based aerospace manufacturers — such as Bell, Bombardier, Pratt & Whitney, CAE and their suppliers — have benefited as a result.
To support this goal, Jaunt announced on May 6 that it would establish design and manufacturing operations in Canada, had appointed Eric Côté as President of the Canadian operations (see “Leadership Moves,” Vertiflite, July/Aug 2021), and was actively seeking Canadian investors.
Côté is a pilot and has recent CEO experience in leading the Soucy Group, a worldwide engineering and manufacturing organization with 10 independent companies; it has 1,800 employees active in the defense, power sports, industrial and agriculture sectors. During Côté's 15-year tenure at Soucy, his strategic vision and leadership allowed him to set up a strong and mobilized organization with an increased presence on five continents.
Before his time at Soucy, Côté spent 15 years with Bombardier Aerospace in senior-level positions (manufacturing engineering, operations strategies, continuous improvement and industrialization), including the establishment of aerospace manufacturing and assembly organizations in other countries.
On May 12, CAE announced it will support Jaunt in developing the company's aircraft systems integration lab in Montreal, Canada. As part of the agreement, CAE and Jaunt intend to build an engineering simulator that will accelerate cockpit design and system development, and will reduce airworthiness flight test time. The Jaunt Aircraft Systems Integration Lab (JASIL) program is designed to de-risk the aircraft program's schedule and manage development costs by identifying integration issues and proving failure modes early in the program.
When Jaunt first announced that it was planning to certify the five-seat Journey at a transport category rotorcraft — FAR Part 29, TCCA CAR 529 and EASA CS-29 — it raised a few questions, since the aircraft has a maximum takeoff weight of less than the 7,000-lb (3,175-kg) Part 27 cutoff.
But Peryea is quick to explain that Jaunt is using Part 29 as the certification basis for the Journey because it represents the highest safety standards for rotorcraft. He believes that’s what passengers and communities will expect if eVTOL aircraft are flying overhead at high frequencies.
The company is very confident about the technology readiness of the SRC system and the ability of each of its technology partners to meet Part 29 requirements, which will also comply with EASA Special Condition for VTOL (SC-VTOL) for “Category Enhanced.”
Compared to the rotorcraft related requirements of Part 23 and Part 27, Part 29 requires that flight critical systems meet the requirements of probability of catastrophic failure of less than 10-9 per flight hour. It also requires the use of Systems Safety Assessment processes, robust software design processes to meet Development Assurance Level (DAL) A for functions that could exhibit catastrophic failures, and sets out specific requirements for bird strike, fatigue and damage tolerance, lightning strike and fire protection. Category A means the aircraft can land or carry on a flight if there is a critical motor failure.
Many of Jaunt’s competitors plan to certify their aircraft under FAR Part 23 regulations, but Peryea points out that rules for eVTOL aircraft are still under development and no one has successfully completed a certification program for the latest Part 23 (Amendment 64) rules.
The opportunity to develop an eVTOL aircraft for the Uber Elevate ridesharing network helped define a lot of the early characteristics of the Journey, but the company recognized that it needed to look beyond Elevate’s three launch cities of Dallas/Fort Worth, Texas; Los Angeles, California; and Melbourne, Australia.
In October 2020, Jaunt announced the establishment of the Access Skyways alliance, a group of partner companies providing expertise to support the integration of AAM.
Jaunt announced it had signed memorandums of understanding (MOU) with PS&S Integrated Services, an architectural and engineering firm with experience in vertiport design, and PRICE Systems, which specializes in predictive cost modeling and has the capability to calculate passenger demand for air taxi services.
The expansion of the Access Skyways is one of the responsibilities of Briceno, which includes establishing partnerships across the AAM ecosystem, similar to what Jaunt is doing with the Tier 1 companies on the aircraft development side.
Jaunt has also secured launch customers for the Journey, which have already provided important insights regarding desirable aircraft features and infrastructure requirements, Peryea noted.
In September 2020, Jay Carter hosted a flight demonstration of the PAV for Jaunt employees and consultants (see “Jaunt Starts a New Chapter,” Vertiflite, Nov/Dec 2020). Briceno says it was a very worthwhile undertaking because it allowed everyone to see firsthand how an SRC flies.
Earlier this year, Jaunt completed three Small Business Technology Transfer (STTR) studies for the AFWERX Agility Prime office, via contracts through the Air Force Research Laboratory. These contracts covered extreme fast charging (XFC), advanced manufacturing of thermoplastics, and acoustics.
Jaunt worked with BAE Systems and Binghamton University in New York to assist in designing a large-scale, fast-charging system nearly twice as efficient as current chargers on the market today.
Working with Triumph/Qarbon Aerospace and Georgia Tech, Jaunt validated and quantified the benefits of using thermoplastics for large-scale structures in the manufacturing process of this new aviation segment.
Lastly, with Penn State and Continuum Dynamics, Inc., Jaunt validated the Journey’s acoustic profile. The company noted in a recent press release, “Our acoustics work confirmed our eVTOL aircraft will operate at the lowest possible noise levels capable with today’s technology and be imperceivable when flying overhead.”
Jaunt expects to establish similar research partnerships with companies and academic organizations in Quebec in the future.
Jaunt Air Mobility believes that the future of vertical flight is harnessing the power of electric propulsion to make slowed rotor compound rotorcraft exceptionally better.
In addition, it recently submitted an SRC design to the US Air Force’s High-Speed VTOL (HSVTOL) Challenge (see “Air Force Challenges Industry for High-Speed VTOL,” pg. 22). This configuration, called the MAV55, uses VerdeGo Aero’s hybrid-electric drive system technology with the GE Aviation Catalyst engine. The MAV55 is designed for an 11,000-lb (5,000-kg) useful load and would carry 12 troops to 1,400 nm (2,600 km) at a cruise speed of 268 kt (500 km/h).
Jaunt also sees other potential applications of SRC technology. With its low noise and low-cost approach, Jaunt Journeys could provide better solutions for the common man, the warfighter and more.
About the Author
Ken Swartz runs the agency Aeromedia Communications in Toronto, Canada. He specializes in aerospace market analysis and corporate communications. He’s worked in the regional airline, commercial helicopter and commercial aircraft manufacturing industries for 30+ years and has reported on vertical flight since 1978. In 2010, he received the Helicopter Association International’s “Communicator of the Year” award.
Administered by The Vertical Flight Society This information on this website is provided for public use. However, you may not copy entire sections of this website and post them on your own website — because that's plagiarism!
2700 Prosperity Ave, Suite 275
Fairfax, Virginia, USA - 22031