Writer

Charlotte Bailey

Canadian biotech company Unither Bioélectronique has made what it claims is the world’s first piloted hydrogen-electric helicopter circuit flight. This was completed on April 10 using a modified Robinson R44, one year after the demonstrator first flew, but not announced until May 7.
The test flight was conducted under an experimental flight permit as part of the ongoing Project Proticity. Announced in August 2024, this partnership between the United Therapeutics subsidiary and Robinson Helicopters is looking to develop zero-emission helicopters based on the latter company’s R44 and R66.
The hydrogen-electric circuit flight builds on the <a href="https://www.ainonline.com/aviation-news/business-aviation/2025-04-07/unither-achieves-1st-hydrogen-powered-helicopter-flight">inaugural flight</a> of the technology demonstrator in April 2025. This was performed using gaseous hydrogen powering two low-temperature proton exchange membrane fuel stacks, with an adjacent battery pack. The hover lasted just over three minutes.
Project Proticity now intends to scale the system to the larger R66. Unither states that its intended end-use of the aircraft is to “help deliver manufactured organ alternatives to patients in need, while creating a scalable zero-emission transportation network.” The partners are targeting future certification pathways with the U.S. and Canadian regulators. &nbsp;&nbsp;
In May 2024, Unither revealed that it was looking to add hydrogen-enabled capabilities to its existing <a href="https://www.ainonline.com/aviation-news/futureflight/2024-08-19/unither-bioelectronics-plans-hydrogen-powered-helicopters">battery-electric</a> research. Having flight-tested three generations of electric R44 prototypes, it explained that it was “deep into the building and testing stage” of cryogenically cooled liquid hydrogen cells. These, explained Unither, could potentially quadruple the all-electric R44’s range: enabling deliveries of organs to transplant centers across the U.S.
Meanwhile, the FAA has issued <a href="https://www.govinfo.gov/content/pkg/FR-2026-05-06/html/2026-08938.htm">special conditions </a>that will apply for a supplemental type certificate to install Skyryse's <a href="https://www.govinfo.gov/content/pkg/FR-2026-05-06/html/2026-08938.htm">fly-by-wire flight controls</a> in the R66 helicopter. Skyryse, which applied for the approval in April 2023, described its technology as "the first fully digitized aircraft operating system that enhances safety and offers optionally piloted capabilities.” The company has been working on autonomous flight systems for several years.

News about environmental issues relating to aircraft operations, including noise issues, emissisions, and regulations. See Fuel for biofuel.

Modified R44 Claims World’s First Hydrogen-electric Helicopter Circuit

Unither Bioélectronique expands envelope of experimental aircraft 

Unither Bioélectronique has made what it claims is the world’s inaugural piloted hydrogen-electric helicopter circuit flight, using a modified R44.

Modified R44 Flies Hydrogen-electric Helicopter Circuit

2024 Corporate Aviation Leadership Summit

News and issues relating to the aerospace industry that are related to the science, engineering and business of flight in space involving civil, industrial and military applications, and similar topics related to flight in the atmosphere of the Earth that are not covered more directly by other AINonline subject channels. In other words, both astronautical and aeronautical subjects, except for those aeronautical topics that are specifically covered elsewhere on this website.

Environmental research program had already used three quarters of previously agreed funding

UK’s FAAM Research Aircraft Formally Ceases Operations 

Charles Alcock

News and developments about airplanes, helicopters and unmanned air vehicles used in all varieties of operations, including airlines, military, business, commercial, general aviation and private.

News and developments about aircraft engines, including turbofan, turboprop, turboshaft and piston.

A joint venture with the University of Nottingham is a product of the H2Gear program

GKN-backed Start-up Focuses on Cryogenic Power Distribution

News and developments about aviation fuel, including jet fuel, aviation gasoline, and biofuel.

News and issues relating to business, corporate and private aviation, primarily regarding turbine-engine-powered airplanes and helicopters. Subjects include aircraft, engines, maintenance, operations, personnel, acquisitions, accidents, safety, security, and training.

Industry calls for changes to Refuel EU rules

SAF Mandate Complicates European Bizav’s Green Intentions

News and issues regarding all manner of civil and military rotorcraft and their powerplants, including helicopters, tilt rotors and unmanned air vehicles.

Technology to fly onboard clean-sheet, all-electric, ducted-fan gyrocopter 

DLR Tests Experimental Vibrational Anti-Icing System  

Curt Epstein

Measure could spur further growth in the SAF industry

NBAA Applauds House Passage of Pro-SAF Legislation

News about bills, laws, regulations and other governmental decisions affecting aviation and aerospace. Topics include FAA re-authorizations, taxes on fuel and aviation activities, environmental legislation, ICAO decisions, governmental mediation of labor conflicts and World Trade Organization disputes and decisions.

EU Court to decide if industry is “an environmentally sustainable economic activity."

EU Court Set to Rule on Business Aviation's Sustainability Status

New developments at FBOs including regulations and noise issues; legal disputes; openings, acquisitions and mergers.

The California FBO/MRO wants to grow sustainably

Desert Jet Partners with 4Air on Sustainability Efforts

News about simulators and training procedures, as well as workforce.

News and issues concerning general aviation, specifically airplanes and helicopters powered by piston and alternative engines (i.e., non-turbine powered aircraft). Subjects include aircraft, engines, personnel, acquisitions, accidents, safety, security and training.

In this article

Robinson R44 Series

Robinson Helicopter Company

More In Sustainability and Environment