• 01 May 2024 06:57 PM
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Electric CTOL/STOL News, May/June 2024

Here’s our roundup of recent news on battery-electric, hybrid-electric and hydrogen-electric conventional takeoff and landing (eCTOL) and electric short takeoff and landing (eSTOL) aircraft for advanced air mobility (AAM) applications.

Safran and Turbotech Test H2 Engine
Safran and Turbotech tested a hydrogen-fueled gas turbine engine for the light aviation market, the two companies said on Jan. 29. The test occurred on Jan. 11 in Vernon, France, and involved a Turbotech TP-R90 regenerative turboprop engine. The initial tests in January used gaseous hydrogen fuel, while a second stage of testing planned for later this year will use liquid hydrogen and a liquid storage system developed by Air Liquide. The tests are in support of the BeatHyFeul joint project, which seeks to explore hydrogen propulsion solutions for light airplanes. It is supported by the French Civil Aviation Authority (DGAC) and is led by Turbotech and Elixir Aviation, with support from partners Safran, Air Liquide and Daher.

Cosmic Aero Raises Seed Funds
Cosmic Aerospace announced on Feb. 6 that it had raised €4.5M ($4.8M) in a seed funding round. The funds will go towards the development of a 24-passenger, battery-powered electric aircraft, the Cosmic Skylark, which the Brussels-based company said could have a range of up to 620 miles (1,000 km). The company is aiming to conduct its first flight of a full-scale demonstrator in 2026, with a service entry planned for 2030. Pale blue dot, a Swedish investment firm, led the round.

Surf Air to Operate 90 Electra eSTOL Aircraft
Surf Air and Electra Aero announced a partnership to offer leased Electra eSTOL aircraft for regional transportation, the two companies said on Feb. 15. Under the agreement, Surf Air, a California-based company that owns Southern Airways Express, secured early delivery positions for 90 Electra eSTOL aircraft, which it intends to integrate into its network and lease to other operators. Additionally, the two companies will collaborate on the development of route networks for Surf Air’s network and a predictive analytics system to reduce operating costs. Virginia-based Electra Aero is developing a nine-passenger eSTOL aircraft (shown); it is currently testing its hybrid-electric EL-2 Goldfinch.

Aura Powers on INTEGRAL E
Aura Aero conducted a power-on test of its two-seat INTEGRAL E prototype on Feb. 19. In a demonstration for investors, partners and the media, the power-on test and propeller revolution represented a milestone for Aura Aero, the Toulouse, France-based company said in a press release. First flight of the aircraft was stated to begin “in a few weeks,” while entry into service is planned for 2026. The INTEGRAL E is an electric version of the company’s INTEGRAL S trainer. The company envisions a 19-seat Electric Regional Aircraft, or ERA, the design for which it unveiled in May 2023 (see “Electric CTOL/STOL News,” Vertiflite, July/Aug 2023).

Whisper Aero Unveils Airliner Concept
On March 1, Whisper Aero unveiled a concept for a 100-passenger electric airliner. The Whisper Jetliner concept features 22 ducted fans integrated into the aircraft’s wing and could have a battery-electric range of up to 769 mi (1,238 km), according to the Tennessee-based sustainable aviation company. Whisper CEO Mark Moore revealed the concept in a presentation at the Ohio Air Mobility Symposium and Whisper submitted the concept as a proposal for NASA’s Advanced Aircraft Concepts for Environmental Sustainability (AACES) 2050 program. The design is the second aircraft concept from Whisper, which unveiled its design for a nine-passenger eSTOL aircraft, the Whisper Jet, in June 2023 (see “Electric CTOL/STOL News,” Vertiflite, July/Aug 2023). Like the Whisper Jet, Whisper Aero does not intend to build the Whisper Jetliner itself, preferring instead to work with partners on turning this concept into a reality.

FAA Approves Pipistrel Velis Electro, 100th Delivered
Pipistrel, the Slovenian light aircraft manufacturer and Textron subsidiary, announced on March 4 that the US Federal Aviation Administration (FAA) had granted it a light sport aircraft (LSA) exemption for the Velis Electro, Pipistrel’s light trainer. The exemption, which the FAA issued on March 1, will allow flight schools in the US to use the Velis Electro, potentially lowering the costs of learning to fly, said Pipistrel in a statement. The Velis Electro is estimated to reduce the cost per flight training hour by 75% compared to a Cessna 175, according to Pipistrel’s petition to the FAA. In what was a first for electric aviation, the European Union Aviation Safety Agency (EASA) certified the Velis Electro in 2020, though it has a more expansive definition of light-sport aircraft than the FAA.

There were already several aircraft in the US, operated under experimental tickets. In addition, Modern Technology Solutions Inc. (MTSI) accepted delivery of a leased Velis Electro in October, to be used by the US Air Force’s AFWERX Agility Prime program for operational assessment, at its New Braunfels National Airport near San Antonio, Texas (see also “Electric VTOL News,” Vertiflite May/June 2024, pg. 74).

Meanwhile, Pipistrel announced the following week that it had produced its 100th Velis Electro, which it delivered to Green Aerolease, “a French sustainable aircraft rental business with ambitions to accelerate the environmental transition of the aviation industry across Europe through its turnkey rental service.” The Velis Electro is now in service in over 30 countries worldwide.

Airbus Gives Update on Hydrogen Airliner Plans
Airbus intends to select a propulsion system for its ZEROe hydrogen airliner in 2026–2027, said Mathias Andriamisaina, Airbus’s lead for ZEROe demonstrators and testing, on March 6. The company will need to decide between burning hydrogen in a turbine engine or using hydrogen fuel cells, explained Andriamisaina in a presentation at the Clean Aviation Annual Forum in Brussels. Airbus intends to launch its program to develop the ZEROe in 2028–2029, with commercial service entry planned for 2035. In January, Airbus conducted a test of a fuel cell-powered engine (see “Electric CTOL/STOL News,” Vertiflite, March/April 2024).

Aviation Week noted that burning hydrogen in a turboprop or turbofan engine is a lighter-weight option, while “using it in a fuel cell to produce electricity…favors efficiency.” Burning hydrogen, however, also produces nitrogen oxides (NOx), while fuel cells only produce water vapor (see “Airbus Highlights Sustainability Initiatives in Annual Summit,” Vertiflite, Jan/Feb 2023). In June 2023, Airbus announced the successful test campaign of its hydrogen fuel cell system, which reached its full-power level of 1.2 megawatts; by the end of the year, the company had powered on the full “iron pod,” including the electric motors needed to spin a propeller, as well as the control units and cooling systems.

Rolls-Royce Tests Electric Motor
On March 28, Rolls-Royce Electrical announced that it had completed the assembly of its 320-kW electric motor and begun initial, passive tests of the direct drive motor. The tests occurred at the company’s facility in Trondheim, Norway, though teams from five Rolls-Royce locations worldwide contributed to the project. Following additional tests of the motor’s functionality, the next stage of testing will take place in Munich, Germany. The electric motor is designed for commercial regional air mobility applications, specifically electric commuter aircraft with a 9–19-passenger capacity. Rolls-Royce announced in November that it intended to sell its Rolls-Royce Electrical unit, primarily comprised of the business that it acquired from Siemens in 2019 (see “Rolls-Royce Retrenches,” Vertiflite, March/April 2024).