Last week, Robinson Helicopter Company announced a collaboration with Unither Bioelectronics, a subsidiary of United Therapeutics, to support development of the hydrogen-electric helicopter that Unither unveiled in May.
The relationship between the companies isn’t new. For years, Robinson has quietly supported Unither behind the scenes, first as the company developed several iterations of a battery-powered R44, then as it swapped over to a hydrogen fuel cell system for better performance and range.
While the collaboration has been ongoing, the decision to formalize the relationship signals the partners’ mutual desire to accelerate progress toward a viable commercial product. It also reflects the forward-looking vision of Robinson CEO David Smith, who took over the reins of the famously conservative helicopter manufacturer in February of this year.
“With the agreement now publicized and shared, I think we’re in a position where we can be more direct and aggressive on achieving the mission of this project, which is to certify an architecture that then can be developed into the R66, which we believe is a better long-term package for what this mission requires,” Smith said in an interview with Vertical.
Unither’s mission is to deliver human organs in support of its parent company, which, under the leadership of CEO Martine Rothblatt, aims to address the ongoing shortage of transplantable organs through a variety of manufacturing techniques.
One of these is xenotransplantation, the use of organs from other species. United Therapeutics has recently been in the news for providing organs from genetically modified pigs to patients who are too sick to qualify for traditional organ transplants, although the company is still working to establish the viability of this approach.
In addition to its in-house development of a hydrogen-powered helicopter, United Therapeutics is also working with eVTOL developers including Vermont-based Beta Technologies. It ultimately aims to have a fleet of zero-emissions aircraft as an alternative to conventionally powered helicopters for rapid deliveries of manufactured organs at scale.
According to Smith, Unither’s compelling use case is sufficient to justify Robinson’s support of the project. “In this case, I don’t think we need mass adoption of these products to make our business case work,” he said. “To me, if we sell relatively small numbers, but it goes into really important missions like United Therapeutics, I think that’s a success.”
Yet he also sees long-term strategic advantages to investing in development of a hydrogen-electric helicopter, which will involve certifying an electric motor, high-voltage distribution system, fuel cell, and hydrogen containment system. “I think those are all phenomenal things to be a part of, and then each of those pieces could contribute differently to a long-term portfolio of options for us,” Smith said.
Meanwhile, Unither will benefit from enhanced access to Robinson’s knowledge and expertise as an original equipment manufacturer (OEM), as well as its substantial production capabilities down the line.
“When you’re trying to make some changes to an already type-certified vehicle, the data sets that the OEM has generated throughout the type certificate program of the baseline aircraft is of high value in terms of assessing the impact of any further design changes to the baseline product,” explained Mikael Cardinal, VP of program management and organ delivery systems and head of the United Therapeutics Organ Delivery Systems (UTODS) development program.
Cardinal said that Unither expects to tap Robinson’s subject matter experts for their input and design critiques as the company matures its hydrogen powertrain into a certifiable configuration. “But bottom line, I would say it’s really a dynamic and fluid relationship, and we are soliciting each other’s expertise based on the specific phases of the program, and it will certainly evolve with time,” he said.
A new design space
Unither’s hydrogen powertrain is a hybrid system that combines a low-temperature proton exchange membrane (PEM) fuel cell with a small booster battery pack. The Quebec-based company is demonstrating the technology on a four-seat R44, but ultimately aims to certify a conversion for the five-seat R66 with both Transport Canada and the U.S. Federal Aviation Administration in the form of a supplemental type certificate (STC).
United Therapeutics’ pursuit of electric and hydrogen-electric aircraft is strongly motivated by sustainability considerations. However, Smith pointed out that a hydrogen-electric aircraft also offers the opportunity for increased redundancy through the use of double or triple stack electric motors that could provide some degree of continued flight capability in the event of a partial failure.
That could conceivably allow a hydrogen-electric R66 to operate in some areas that are currently off-limits to single-engine helicopters, such as over congested areas in Europe.
“I don’t want to put a single motor stack back into a single-engine application — I want to give that that redundancy advantage,” Smith said, noting that Robinson and Unither have been having discussions on this topic with leading motor manufacturers. “It is an advantage that you have to design for; you have to make sure that it can do that and the architecture is capable of doing that under a range of conditions and failure modes, but it can be very promising.”
Smith said he also expects a hydrogen-electric helicopter to offer an improved noise signature versus conventional helicopters, although that will need to be validated through testing.
“When you compare it with a turbine — a lot of folks love a turbine sound, so I’m not saying it’s an unpleasant noise — but for residents and folks that are in neighboring communities, I think they’re going to appreciate a considerable reduction in noise,” he said.
When Cardinal unveiled Unither’s hydrogen-electric R44 demonstrator at the Vertical Flight Society’s Forum 80 in Montreal, Quebec, in May, he said that its first flight was “hopefully imminent.” However, the aircraft has remained in ground testing while Unither’s team works through some technical challenges.
“In the last few months, we’ve continued to perform additional ground testing to build confidence in our systems design and integration readiness, and we’re making a lot of learnings on a weekly basis to inform that readiness,” he told Vertical.
One particular area of focus has been the performance of the thermal management system, which must extract a large amount of heat from the fuel cell — a particular challenge in hovering flight with no ram air flow to assist. Typically, heat accounts for around half of the total energy produced by a PEM fuel cell.
“This is still a challenge, but we’ve had very positive results lately in the last few weeks,” Cardinal said, also mentioning electromagnetic interference (EMI) and electromagnetic compatibility (EMC) as another predictable challenge of system integration.
“I know we were expecting a first flight way early, but it is what it is, and we are making sure to develop that with a very robust risk management process in place,” he said.
For the time being, Unither’s principal focus is naturally on getting its technical demonstrator airborne. Looking to the future, however, both Unither and Robinson see a need for industry collaboration on hydrogen standards and infrastructure development, and are eager to participate in those discussions.
“I don’t think it’s desirable for any solo applicant to show up at the FAA or Transport Canada or any other regulator with a strategy that has been developed by a single team,” Cardinal said. “So I think that bringing the learnings in common for all those industry players that are developing and working on hydrogen power systems is obviously beneficial.”
Smith said that he can envision hydrogen being part of Robinson’s future product line, beyond the initial STC for the R66. “I could easily see a larger aircraft being of benefit for a hydrogen-based solution,” he said, noting that the tourism market in particular could benefit from a quieter, more sustainable form of propulsion.
However, he emphasized that hydrogen will be just one future option of many for Robinson customers.
“We’re not stopping production of any of our current products,” Smith said. “We’re not saying that the future will all be hydrogen. We’re definitely saying that we need to offer different types of tools for different types of customers.”
