Bjorn’s Corner: Air Transport’s route to 2050. Part 8

By Bjorn Fehrm

February 7, 2025, ©. Leeham News: We do a Corner series about the state of developments to replace or improve hydrocarbon propulsion concepts for Air Transport. We try to understand why the development has been slow.

We have covered the progress of battery-based aircraft and hybrids, where the last Corner was about the most sensible hybrids, the mild hybrids. Now, we turn to hydrogen-fueled alternatives.

Figure 1. The operation of a PEM fuel cell. Source: NASA.

 

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Bjorn’s Corner: Air Transport’s route to 2050. Part 7.

By Bjorn Fehrm

January 31, 2025, ©. Leeham News: We do a Corner series about the state of developments to replace or improve hydrocarbon propulsion concepts for Air Transport. We try to understand why the development has been slow.

We have covered the progress of battery-based aircraft and hybrids, both serial and parallel hybrids. A couple of mild hybrids have a larger chance of success than the ones we described. We will look into these and then start looking at different hydrogen-fueled alternatives.

Figure 1. The LEAP-1A with auxiliary gearbox. Source: Safran Transmissions.

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Bjorn’s Corner: Air Transport’s route to 2050. Part 6.

Bjorn Fehrm

January 24, 2025, ©. Leeham News: We do a Corner series about the state of developments to replace or improve hydrocarbon propulsion concepts for Air Transport. We try to understand why the development has been slow.

We have covered why the progress of battery-based aircraft is slow and also described what to expect at the end of this decade and the beginning of next.

Now, we look at hybrids, an inherently more complex design. Upstarts are changing to hybrids after realizing that battery-only aircraft will not have useful range this side of 2030.

Figure 1. The Heart Aerospace ES-30 has passed the phases in the article. Source: Heart Aerospace.

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Bjorn’s Corner: Air Transport’s route to 2050. Part 5.

By Bjorn Fehrm

January 17, 2025, ©. Leeham News: We do a Corner series about the state of developments to replace or improve hydrocarbon propulsion concepts for Air Transport. We try to understand why the development has been slow.

We have covered why the technical progress of battery-based aircraft has been slow. Now we look at what type of missions it can do this decade and beyond and why the limitations.

Figure 1. The Diamond eDA40 electric trainer. Source: Diamond. Read more

Bjorn’s Corner: Air Transport’s route to 2050. Part 4.

By Bjorn Fehrm

January 10, 2025, ©. Leeham News: We do a Corner series about the state of developments to replace or improve hydrocarbon propulsion concepts for Air Transport. We try to understand why the development has been slow.

We listed the different projects in the second Corner of the series that have come as far as flying a functional model or prototype. In Part 3, we went through some of the causes of the slow growth. It was a mix of inexperienced startup managments, all wanting to be the new Elon Musk but lacking elementary knowledge in the aeronautical field, to what is the real hard part of an alternative propulsion concept.

Many startups developed new electric motors for eAirplane or eVTOL use, a relatively straightforward development when the real hard part is the batteries. We described how batteries differ significantly from fuel as an energy source in Part 3.

Now, we add a market aspect that is poorly understood by most players.

Figure 1. The Pipistrel Velis Electro trainer. Source: Pipistrel.

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Bjorn’s Corner: Air Transport’s route to 2050. Part 3

By Bjorn Fehrm

November 1, 2024, ©. Leeham News: We do a Corner series about the state of developments to replace or improve hydrocarbon propulsion concepts for Air Transport. We will find that development has been very slow.

Last week, we listed the different projects that have come as far as flying a functional model or prototype, as we need this filter to reduce the hundreds of projects that have declared they want to develop such an aircraft type. We can see that we have only a certified two-seat trainer, and one project has a prototype that has started certification, the CX300 six-seater in Figure 1.

Why is the progress so slow?

Figure 1. The Alia CX300 six-seater started certification in 2023. Source: Beta Technologies.

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Bjorn’s Corner: Air Transport’s route to 2050. Part 2.

October 24, 2024, ©. Leeham News: We do a Corner series about the state of developments to replace or improve hydrocarbon propulsion concepts for Air Transport. We will find that development has been very slow.

We don’t have, and will not have, a certified and produced aircraft that can transport passengers using anything but classical propulsion concepts this side of 2028 and probably 2030 if we put the bar above five passengers.

This is 14 years after the flight of the Airbus E-Fan in 2014, which started a multitude of studies and projects to explore new, more environmentally friendly ways to propel aircraft.

Figure 1. The Airbus E-fan flying at the 2014 Farnborough Air Show. Source: Wikipedia.

Why is the progress so slow? Normal aircraft development takes seven to a maximum of nine years?

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Heart Aerospace’s revised ES-30, Part 3. UPDATED

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By Bjorn Fehrm

October 24, 2024, © Leeham News: We analyze Heart Aerospace’s latest evolution of the hybrid ES-30. The latest version, presented in spring 2024, is a parallel hybrid, putting gas turbine turboprop engines outside the electric motor engines.

After examining what such a parallel hybrid system means for aircraft dimensions and masses, we now fly the aircraft on a typical US short-haul route through our Aircraft Performance and Cost Model (APCM) to assess its operational performance.

Does the ES-30 make operational sense for an airline that needs a short-haul feeder?

Summary:
  • The parallel hybrid architecture gives the ES-30 certain operational flexibility to fly routes over 100nm, making it possible to replace present 30 seaters on such short routes.
  • However, the operational costs are considerably higher than today’s 30-seaters. As always, the problem is the battery costs.
  • UPDATE: Heart Aerospace contacted us after the article was published. The article has been complemented with their information.

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Bjorn’s Corner: Air Transport’s route to 2050. Part 1.

By Bjorn Fehrm

October 18, 2024, ©. Leeham News: In Corners over the last years, we have covered new airliner technology and engine developments that would apply to the next-generation airliners in the largest segment of the market, the single-aisle segment, or as we like to call it, the Heart of the Market segment, as it’s not sure it will be a single-aisle aircraft.

The series has assumed this generation will be hydrocarbon-fueled gas turbine-propelled airplanes. Therefore, it has not covered the current state of alternatives to gas turbine-based hydrocarbon propulsion.

We will cover this now. We are now 10 years into the discussions and work of reducing Air Transport’s reliance on hydrocarbon fuels, which started in earnest when Airbus flew the E-Fan battery-electric aircraft at the Farnborough Air Show in 2014, Figure 1.

How are we doing?

Figure 1. Airbus E-Fan at Farnborough Air Show 2014. Source: Wikipedia.

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Heart Aerospace’s revised ES-30, Part 2

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By Bjorn Fehrm

October 17, 2024, © Leeham News: We analyze Heart Aerospace’s latest evolution of the hybrid ES-30 (bottom aircraft in the picture), which replaces the original battery-based 19-seater (top aircraft) and the original ES-30 (mid aircraft).

The latest version, presented in spring 2024, is a parallel hybrid, putting gas turbine turboprop engines outside the electric motors. What are the advantages of the parallel hybrid version, and will it make the Heart ES-30 project more likely to succeed?

We use our Aircraft Performance and Cost Model (APCM) to understand the design choices and the costs involved.

Summary:
  • The latest revision of the Heart Aerospace hybrid electric aircraft, the ES-30, takes the hybrid architecture from a serial to a parallel system. It simplifies the architecture.
  • Does the revised ES-30 make airline operational sense? We analyze this using our Aircraft Performance and Cost Model.

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