Outlook 2024: Milestone year for alternative energy development

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By Scott Hamilton and Bjorn Fehrm

Jan. 18, 2024, © Leeham News: Twenty twenty four is 10 years after the Sustainable Aircraft discussions started when Airbus flew its battery-powered E-Fan before the world’s OEMs and press in July 2014 at the Farnborough Air Show.

The time that has passed is longer than the normal development time for a new aircraft, and what have the hundreds of projects that started in the wake of the E-Fan achieved? We have one new two-seat trainer, the Pipistrel Velis Electro, in production, but not much else.






A typical urban air mobility vehicle concept.

There has been no lack of electric airplane project announcements, one more fanciful than the other. Operational ranges and economics that will enable the replacement of the typical regional turboprops have been presented, but the two functional demonstrators we have in the air that go beyond nine seats are hydrogen fuel cell aircraft, not battery-electric or hybrid electric.

We have hybrid five and nine-seat commuters flying in prototypes, and a couple of hybrids will start production during the year. These will reach the market in 2025 or 2026, but how operationally viable these is still not clear. But beyond nine seats, there are only plans, no projects that plan to fly prototypes this year or next.

The one-battery electric project, Eviation Alice, flew once, then packed up, declaring we needed better batteries. It’s clear the job of exchanging the hydrocarbon combustion engine for aircraft is much harder than thought. The problem is that aircraft are supposed to fly for hours, and the energy density of normal fuel is still 50 times higher than for batteries.

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The Exception to the Green Propulsion Rule

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By Bjorn Fehrm

November 30, 2023, © Leeham News: The interest in Green alternative propulsion for airliners started in earnest at Farnborough Air Show 2014, where Airbus flew the E-Fan battery-electric aircraft. What followed was a dense stream of alternative propulsion airliner projects.

They all have in common that nothing much has come out of them. We have a Pipistrel two-seat trainer that can fly for 50 minutes on batteries, but not much else. More elaborate projects have wide slips in their plans, and nine years later, we lack real prototypes for all projects.

We have functional models flying for nine-seat hybrids and 19/30-seat hydrogen fuel cell aircraft that swap one engine for a Green alternative. Of the latter, there is one project that stands out from the rest. It has shown real progress over the last years and has realistic plans for a 55-seat hydrogen airliner that can be operational in three to four years.

We will analyze why the Universal Hydrogen ATR fuel cell project is the exception to the “Green Propulsion Rule,” that nothing comes out of all plans, and why it could be the first Green Propulsion airliner, ending a 10-year draught.

Figure 1. The Universal Hydrogen Dash 8-300 functional demonstrator. Source: Universal Hydrogen.

  • A Green Propulsion project means the airliner does not use hydrocarbon-burning (Kerosene or SAF) gas turbines.
  • The project that breaks the rule that nothing seems to reach practical use this side of 2030 is the Universal Hydrogen ATR project.

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Hydrogen flight integrator AeroTec created 3,000 parts in 12 months

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By Bryan Corliss

March 9, 2023 © Leeham News – AeroTec learned “a lot about hydrogen” as it prepared Universal Hydrogen’s (UH2) Dash-8-300 flying testbed for its first flight last week

AeroTec Chief Technology Officer Dale Goulding./AeroTec photo

“Hydrogen wants to escape,” said Dale Goulding, the chief technology officer for Seattle-based AeroTec. “It’s a very small molecule that wants to get out of whatever container you put it in.” 

For that reason, Universal Hydrogen’s modular capsule makes refueling easier than it would be if the companies tried to replicate the fuel-pumping process used to refuel carbon-powered aircraft, he said. 

“It’s been no problem at all,” Goulding said. “Just roll them in and out. It’s real easy.”

Goulding led a team of roughly 60 AeroTec employees working out of Grant County International Airport in Moses Lake, WA., which was where Universal Hydrogen’s first flight took place on March 2. The plane took two passes over the airfield, flying with a hydrogen fuel cell powering one propeller, while a second kerosene-powered motor was on idle, in case it was needed.

The short flight was intended to “get up, get down safely, then look at all the data,” he said; taking concepts out of the lab and putting them into the sky.


  • Hydrogen fuel cell, electric motor power propeller
  • AeroTec hustled to create 3,000 unique parts
  • Next steps are up to Universal Hydrogen

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First flight of Universal Hydrogen Dash 8 opens new era, company says

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By Scott Hamilton

March 6, 2023, © Leeham News: Universal Hydrogen (UH2) last week took off with its demonstrator aircraft for what it believes is the beginning of a new era.

The first flight of a hydrogen-powered De Havilland Dash 8-300, developed by Universal Hydrogen, occurred on March 2, 2023. Credit: Leeham News.

The Dash 8-300 took off from the Moses Lakes (WA) airport at 8:41 am on March 2 for a short flight circling the former US Air Force Base, now called Grant County International Airport. On one circle, the test pilots throttled back the Jet A-fueled Pratt & Whitney PW123 engine, flying on the No. 2 electric motor, powered by hydrogen fuel.

Thus, UH2’s Dash 8 became the second largest plane (after the Soviet-era Tu-155) to fly on hydrogen and the first to fly solely on clean energy given that the No. 1 engine was at idle.

LNA previously reported details of UH2’s airplane plans.

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How UH2 moves forward is detailed below.


  • UH2 raised $100m. Another $200m-$250m is required to bring the aircraft to market.
  • UH2 has 247 orders and commitments.
  • ATR-72 will be the first H2-powered airliner to enter service. The Dash 8-300 will follow.
  • A fueling company, not an airplane company.

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