Heart Aerospace’s revised ES-30

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By Bjorn Fehrm

September 26, 2024, © Leeham News: Heart Aerospace has revised its environmentally friendly aircraft for the third time. The variants started in September 2020, when Heart presented an all-electric, battery-based 19-seat airliner that should test fly by now and be available in 2026, Figure 1, top aircraft.

Two years later, in September 2022, it all changed. The aircraft was changed to a 30-seater with a serial hybrid propulsion system using turboextenders to increase the operational range, Figure 1, aircraft two.

After another 20 months, the configuration changed again to the third iteration in Figure 1, which will fly in prototype in 2026 and be available to airlines in 2029.

In an article series, we explain the reasons for these changes and analyze whether the changes in the aircraft have increased the likelihood of the ES-30 entering the market in 2029.

Figure 1. The Heart Aerospace regional airliner series. Top, the ES-19, then the ES-30, and finally, the revised ES-30. Source: Heart Aerospace.

Summary:
  • Heart Aerospace has followed the typical trajectory for an electric aircraft startup.
  • It begins with an all-electric, battery-based airliner that will change regional flying.
  • Gradually, reality sets in, and all-battery architecture becomes a serial hybrid and, finally, a parallel hybrid.
  • We analyze if the evolution trail increases the chances we will fly on Heart Aerospace airliners come 2030.

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Bjorn’s Corner: New engine development. Part 22. High Turbine technologies.

By Bjorn Fehrm

August 30, 2024, ©. Leeham News: We do an article series about engine development and why it has longer timelines than airframe development. It also carries larger risks of product maturity problems when it enters service than the airframe of an airliner.

We reached the turbine part on our way through the engine, where we last looked at high-pressure turbine temperatures. It’s the most stressed part of the engine and, in most cases, decides its durability. To understand why, we look closer at turbine technologies.

Figure 1. Our example engine, the LEAP-1A, is in cross-section with booster to compressor bleed valve area marked with a red circle. Source: CFM.

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Maeve, P&W Canada team for new hybrid propulsion system airplane

By Bjorn Fehrm and Scott Hamilton

July 24, 2024, © Leeham News at Farnborough International Airshow: Start-up airplane company Maeve and Pratt & Whitney Canada (PWC) have teamed for the design of a new eco-airplane driven by a new type of hybrid electric propulsion system with a target service entry date of 2032.

The M80 aircraft is the latest iteration of a design conceived by Maeve of the Netherlands. It is a 76 to 96-seat twin-engine aircraft that is compliant with the restrictive US pilot Scope Clauses, which limit the size, number, and weight of airplanes operated on behalf of US major airlines. Maeve originally designed a four-engine, 44-passenger electric aircraft called the M01.

Figure 1. The Maeve M80 combines an all-new powerplant from Pratt & Whitney Canada and downward wing droops instead of upward winglets. Source: Maeve.

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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.

Summary:
  • 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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Bjorn’s Corner: New aircraft technologies. Part 29. Detailed design

By Bjorn Fehrm

September 8, 2023, ©. Leeham News: We described the Preliminary design phase of an airliner development program over the last weeks. Now our project is transitioning into Detailed design.

It’s the most challenging part of the project as we now go from perhaps a thousand people involved at the OEM into tens of thousands and even more people at consultancies and suppliers.

 

Figure 1. A new airliner family development plan. Source: Leeham Co.

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The reality behind the eVTOL industry’s hyperbole, Part 7.

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By Bjorn Fehrm

August 24, 2023, © Leeham News: We have looked at the promises the VTOL industry made in their Investor prospects and what the reality is as the VTOLs come closer to Certification and production.

We started by using Joby and Archer as examples; now, we wrap the series by looking at some other top VTOL OEMs and how their claims have changed as the projects come closer to reality.

Figure 1. The Lilium jet VTOL. Source: Lilium.

Summary:
  • Joby Aviation and Archer are not alone in backpedaling on promised performance as certification nears; other OEMs that are investor-financed have the same problem.
  • In summary, the VTOLs in the first generation can only fly short-range missions. Longer flights run into energy reserve and cost problems.

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Bjorn’s Corner: New aircraft technologies. Part 25. Efficient development

August 11, 2023, ©. Leeham News: We have described a number of technological advances that can be used to make the next-generation airliners more efficient and, thus, more environmentally friendly.

Part of developing more efficient next-generation aircraft is to change the development process to be more efficient. The last Boeing aircraft, the 787, took 7.5 years from launch to entry into service, and Airbus A350 took 8.5 years.

The target is to reduce this by up to 50%, but how?

Figure 1. The Airbus A350 development schedule. Source: Airbus.

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The reality behind the eVTOL industry’s hyperbole, Part 4.

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By Bjorn Fehrm

August 3, 2023, © Leeham News: We look at the promises that the VTOL industry has made in their Investor prospects and the reality as they come closer to Certification and Production.

After looking at claims of range and utility, we now look at the operating economics. To do that, we need to predict the net sales price of these machines. We use our Aircraft Performance and Cost Model (APCM) to predict the production cost over time and, thus, the needed net sale price of the VTOLs.

Figure 1. The Archer Aviation Midnight VTOL mockup at the Paris Air show. Source: Leeham Co.

Summary:
  • The VTOLs are big; the Archer Midnight is the size of a nine-seater commuter aircraft (Figure 1). Aircraft costs are related to size and weight.
  • VTOLs use aeronautical production methods and supply chains for parts and systems. The production costs are, therefore, predictable.

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The reality behind the eVTOL industry’s hyperbole, Part 3.

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By Bjorn Fehrm

July 27, 2023, © Leeham News: We look at the promises that the VTOL industry has made in their Investor prospects and what the reality is as they come closer to Certification and present their production-level prototypes. We also analyze whether these capabilities will be the final level.

Today we go through the trickiest part of any electric aircraft or eVTOL, the batteries. They are large, very heavy, and the most difficult part to certify on the aircraft, as the battery is dangerous if not designed, produced, and managed correctly.

Figure 1. The Joby Aviation S4 production prototype. Source: Joby Aviation.

Summary:
  • The battery system of an eVTOL sets restrictions on the operational usefulness of the category.
  • The everyday operational utility of VTOLs is far from the industries’ claims.

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The reality behind the eVTOL industry’s hyperbole, Part 2.

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By Bjorn Fehrm

July 20, 2023, © Leeham News: We look at the promises that VTOL OEMs made in their Investor prospects and the scale-down in capabilities as Certification comes closer. We also analyze whether the reduced capabilities will be the final cuts.

In the end, it’s about how operationally useful real-world eVTOL will be and what mission they do better or cheaper than helicopters. It will decide whether the category will have a breakthrough or not.

Figure 1. The Joby Aviation S4 production prototype. Source: Joby Aviation.

Summary:
  • The Investor’s presentations from eVTOL OEMs are full of “up to” for speeds and feeds.
  • When we use our aircraft and eVTOL performance model, the reality is well short of the claims.

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