The Future of Advanced Air Mobility

Tier 1 Achieves First Flight With Electrified Robinson R44 Helicopter

Tier 1 Engineering conducted the first flight of an all-electric Robinson R44 using the MagniX 350 electric propulsion unit (EPU) earlier this month. The three-minute flight took place June 4 at the Los Alamitos Army Airfield in Southern California in a little over six months since the start-up selected the MagniX motor in December 2021.

The integration of the MagniX EPU has been handled by Tier 1, which has developed its own battery system. In the first instance, the electric version of the four-seat helicopter is being developed for Lung Biotechnology PBC, a biotech company that is focused on alleviating the shortage of transplantable human organs. 

"This historic flight, of an all-electric helicopter with a certifiable electric engine, was an important step towards obtaining aircraft certification. We are excited to expand the flight tests to greater distances and demonstrate safe reliable all-electric flight," said Tier 1 president Glen Dromgoole. Tier 1 is working with the Los Angeles FAA Aircraft Certification Office (ACO) on the “e-R44” project to obtain a supplemental type certificate for the conversion program. Lung Biotechnology PBC plans to acquire a fleet of aircraft to fly transplant organs.

Engine supplier MagniX has been powering all-electric aircraft since December 2019. The company’s electric motors have been flown on fixed-wing aircraft including the Cessna 208B Grand Caravan and DHC-2 Beaver and it has been selected to power larger aircraft under development including a hydrogen-fueled, 40-seat Dash 8, Faradair’s 18-passenger Beha, and the nine-seat Eviation Alice. The company is based in Redmond, Washington.  

Tier 1 first flew an all-electric R44 in 2016 using a 1,100-pound lithium-polymer battery pack and twin electric motors from Rinehart Motion Systems. Other all-electric helicopters flew as early as 2010 with Sikorsky's Firefly project. 

Tier 1 Engineering has selected MagniX’s Magni350 electric propulsion unit (EPU) to power its planned converted version of the Robinson R44 helicopter. The start-up is seeking an FAA supplemental type certificate (STC) to bring the eR44 model into commercial service to carry human organs for transplant procedures.

The company has yet to publish performance data for the production version of the eR44, but it is expected to have a flight endurance of around an hour at speeds of around 90 mph. The standard piston-powered R44 can fly up to 345 miles.

Another California-based start-up, Eco Helicopters, has been working on a plan to use electric-powered R44s for air taxi services. It has previously worked with Tier 1 Engineering to achieve this objective.

Lung Biotechnology is owned by Martine Rothblatt, whose United Therapeutics group has also committed to using Beta Technologies' Alia 250 eVTOL aircraft and EHang's EH216 Autonomous Aerial Vehicle for organ-transplant flights.