• 08 Nov 2022 08:25 AM
• 0

Tier 1 Engineering’s Electric e-R44 Makes First Cross-Country Flight

By Kenneth I. Swartz
Vertiflite, Jan/Feb 2023

On Oct. 29, Tier 1 Engineering, in collaboration with Lung Biotechnology PBC, invited the Vertical Flight Society to the scenic Coachella Valley of California to witness the world’s first all-electric cross-country helicopter flight.

More than 700 electric vertical takeoff and landing (eVTOL) aircraft concepts have been catalogued in the authoritative VFS World eVTOL Aircraft Directory (see www.eVTOL.news/aircraft), but only a small number have flown as full-scale prototypes, and only a handful with an experienced pilot at the controls, and only the Tier 1 Engineering battery-electric e-R44 has been flown with two people onboard (see “Tier 1 Engineering Pioneers Electric e-R44,” Vertiflite, July/Aug 2022).

Now Tier 1 Engineering has raised the bar again with its first e-R44 flight outside its US Federal Aviation Administration (FAA)-approved test site at Los Alamitos Army Airfield, six miles (9.6 km) east of Long Beach Airport.

The third-generation battery-electric e-R44 conversion of the popular Robinson R44 helicopter was piloted by Ric Webb, CEO of Part 135 charter operator OC Helicopters, and Dr. Martine Rothblatt, CEO of United Therapeutics; the helicopter was outfitted with a 50-lb (23-kg) payload to simulate a transplant organ care system in the rear cabin.

The helicopter took off from Jacqueline Cochran Airport (KTRM) and landed at Palm Springs International Airport (KPSP) at 11:11 am, covering the FAA-approved 24-mile (39 km) route in a flight time of 20 minutes.

The e-R44 was greeted by dozens of guests invited to Palm Springs Airport by Tier 1 Engineering and United Therapeutics, the project sponsor, to witness the historic occasion, including representatives of electric-engine maker, magniX, Unither Bioélectronique and the Vertical Flight Society.

“This was the first-ever electric-helicopter flight between two cities and between two airports,” said Rothblatt, adding that it demonstrated that “it is practical to deliver transplantable organs by electric helicopters from hospital to hospital.”

“The e-R44 is perfectly capable of flying 20-minute trips with a good reserve,” said Glen Dromgoole, Founder and Principal of Tier 1 Engineering, noting the battery cells had a 50% state of charge (SOC) on landing.

“We believe we're developing a really practical solution for short duration rotorcraft flights such as organ deliveries, pilot training, scenic tours and other inner-city trips.”

Recognized Visionary

Rothblatt has a well-deserved reputation for looking far into the future and orchestrating new business and technology outcomes.

“I've always had a strong personal attraction to aviation since taking my first flight at Santa Monica Airport while I was in college,” she explained. “And over the years, my fascination with aviation grew. I became interested in satellite communications as a way to literally fly outside of the planet's atmosphere, to be in continuous free fall, yet stay above the earth in outer space.”

“That fascination with satellite communications led me to build, design and launch a number of communication satellites, culminating with the Sirius XM satellite system, which today provides lifesaving weather information to literally tens of thousands of aircraft in flight over North America.”

Rothblatt was CEO of Sirius XM in 1994 when the family’s eight-year-old daughter, Genesis, was diagnosed with pulmonary arterial hypertension (PAH), a serious, life-threatening disease.

“I was completely crushed by this news. And I decided over a period of weeks of deep soul-searching to quit all my positions in satellite communications and devote my entire life to creating a cure to save my daughter,” said Rothblatt.

After a comprehensive search, Rothblatt was able to obtain the intellectual property rights to a promising drug therapy that had never entered commercial production — which ultimately saved Genesis’ life and led to the founding of United Therapeutics in 1996. Its four PAH medicines today have literally saved the lives of tens of thousands of people.

Over the past decade, the company’s subsidiaries have made tremendous progress addressing the acute national shortage of transplantable lungs and other organs with a variety of approaches that either delay the need for such organs or expand the organ supply.

This includes Lung Bioengineering, Inc.’s use of a dome-like ex-vivo lung perfusion device (ex vivo means “outside the body”) — first pioneered at Toronto General Hospital in Ontario, Canada — to extend the preservation time of lungs and allow organs that once would have gone unused to be considered for transplant.

The company has also made major investments in xenotransplantation, which uses the hearts and kidneys of genetically modified pigs in human transplantation.

“Earlier this year, we saved the first life of a man who was dying of heart disease, with a genetically modified heart grown in a pig in our company's laboratories,” said Rothblatt, who recently appeared at CNN’s Life Itself conference to talk about UT’s groundbreaking technology that allows pig lung scaffolds to be 3D printed with human stem cells to make a patient-specific organ.

“Our project today began in 2016, about six years ago, when I first met with Glen Dromgoole ... and I presented to him the United Therapeutics business plan of creating an unlimited supply of transplantable organs, and also our company's mission to do everything we can with as low a carbon footprint as possible,” explained Rothblatt. 

The biotechnology company's headquarters in Silver Spring, Maryland, for example, is the 210,000-ft² (19,500-m²), elliptical-shaped "Unisphere," which became the largest site-powered net zero commercial building in the US when it opened in 2018.“Our mantra is that it is possible to both save the lives of our patients and save the atmosphere of our planet,” she added.

Electric Vertical Flight

Rothblatt has to become one of the leading champions of electric vertical flight and was the 2022 recipient of the Vertical Flight Society’s Paul E. Haueter Award, which is given for an outstanding technical contribution to the field of vertical takeoff and landing (VTOL) aircraft development other than a conventional helicopter or an operational vertical flight aircraft (see “78th Annual Grand Awards Ceremony,” Vertiflite, July/Aug 2022).

The dream of electric vertical flight is not new, but it has taken decades for the enabling technology to mature (see “Orlando Helicopter's Electric Sikorsky S-52,” Vertiflite, Nov/Dec 2021), which is a process well understood by this serial entrepreneur and technology visionary.

“United Therapeutics’ mantra is to always have multiple shots on goal, because developing a revolutionary new technology like electric vertical aviation is such an uncertain and risky endeavor that you can never predict the future perfectly to know all the things that could go wrong or might go wrong or might go right that you hadn't anticipated, for example, [hydrogen] fuel cells are rapidly becoming more and more practical,” said Rothblatt.

“I love technology development, but nobody is smart enough to know exactly the straight line from here to where you go. It's like playing chess. At the beginning of a chess game, even the most brilliant chess player can't know all the moves to victory. What you can know are the moves to kind of gradually control the center of the board and maximize your optionality. And that's what I've tried to do in electric aviation.”

An accomplished fixed-wing and helicopter pilot, Rothblatt started researching the feasibility of electric vertical flight and shared the specifications of a zero-emissions electric rotorcraft with a number of aerospace companies to launch a research project. Dromgoole was the first person to positively respond to Rothblatt’s line of inquiry. Tier 1 Engineering then received a contract in early 2016 to rapidly build and fly a proof-of-concept electric helicopter based on the hugely popular four-seat Robinson R44.

Rothblatt’s early-stage funding of Tier 1 Engineering’s e-R44 conversion in Santa Ana, California — as well as Beta Technologies’ Alia-250 electric aircraft in Burlington, Vermont; EHang’s multicopter eVTOL aircraft in Guangzhou, China; and Piasecki Aircraft’s hydrogen-powered PA-890 — were all driven by a much larger vision to create a new zero-emissions transportation system to fly the growing supply of transplant organs that will be available in the mid-to-late 2020s (see “Electric VTOL for Organs on Demand,” Vertiflite, March/April 2019).

Third Generation e-R44

Tier 1 Engineering took delivery of a prototype magni250 on Dec. 6, 2021, to integrate into its third-generation e-R44, which will be the basis for its FAA supplemental type certificate (STC) application (see “Tier 1 Teams with magniX for New e-R44,” Vertiflite, Jan/Feb 2022). The airframe of the proof-of-concept e-R44 aircraft, N3115T, is being reused as a platform for the new electric motor, which has two modules stacked in parallel and powered by separate inverters for redundancy.

The magni250 is twice the diameter of the original YASA motor, but is a better match to the speed and torque of the Lycoming IO-540-AEA5 leaded-fuel piston-engine used on the standard Robinson R44.

This has helped to simplify the e-R44 rotor drive system by replacing the engine reduction gearbox that was required for the 5,600 RPM YASA motor, as well as the R44’s original vee-belt drive and automatic tensioner with a synchronous belt drive. The changes have simplified pilot workload and result in additional weight savings.

The initial ground runs of the third-generation e-R44 began behind the Tier 1 offices in Santa Ana on March 31, 2022, with Webb and Rothblatt performing system checks to validate the cooling system and engine controls of the magni250 electric engine.

This was followed by a first flight at Los Alamitos on June 4 that lasted three minutes, with Webb and Rothblatt once again at the controls.

Cross-Country Flight

Tier 1 Engineering has been planning a cross-country e-R44 flight for several years, but ground and air testing of the new magni250 propulsion system delivered last December needed to mature before the FAA would grant the required flight permit.

Dromgoole told VFS that the third-generation e-R44 was subjected to more than 50 ground tests before the e-R44 was ready to make its first hover, including low and high-power runs with the aircraft anchored firmly to the ground in Santa Ana. Some of the tests simulated various engine fault scenarios and the pilot response.

Since early June, the helicopter had completed 16 test flights totaling approximately three hours, as well as extensive testing at full power with the e-R44 anchored to the ground through the summer.

The e-R44 was brought by trailer to Thermal Airport in the week prior to the flight, along with a ground charging unit.

On the morning of the record setting flight, Webb and Rothblatt flew the approved route in a piston-engine Robinson R44 owned by Lung Biotechnology shortly before they took off in the e-R44.

“Today was absolutely thrilling,” said Rothblatt after landing. “I flew together with my pilot Ric Webb and we were backed up by a whole team of flight engineers at Tier 1 Engineering.”

The e-R44 “was a completely stable platform. We were able to monitor changes in torque, temperature and battery state of charge. It was very stable. It went as predicted from our numerous ground tests and earlier short flight tests. We also monitored our altitude, air speed [for this] FAA-approved flight profile.

“And having previously test flown the flight in a gas-powered R44, I would say this e-R44 flew just as well, if not better, [and was] much quieter. And with a very good feeling in your heart that while you're flying this e-R44, you are effectively taking carbon dioxide out of the atmosphere because you're not putting any more in,” said Rothblatt.

 

Header image: The third-generation battery-electric e-R44 conversion flew 24 miles (39-km) between Jacqueline Cochran Airport (KTRM) and Palm Springs International Airport (KPSP). Photo Dan Megna.