Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- Parent agency, FAA often at odds as politics outweighs safety June 26, 2025
- Electric Flight and the Ugly Duckling June 25, 2025
- Engine makers tout “Plan A” but have “Plan B” backups in R&D June 23, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 27. June 20, 2025
- Pontifications: A Personal Note June 19, 2025
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.
Bjorn’s Corner: New engine development. Part 24. New versus old, GTF versus V2500
By Bjorn Fehrm
September 13, 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 have covered the engine’s different parts and their technology challenges. We now look at some examples of recent developments with problems and put them in a historical perspective.
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.
Bjorn’s Corner: New engine development. Part 19. Turbines.
By Bjorn Fehrm
August 9, 2024, ©. Leeham News: We do an article series about engine development. The aim is to understand why engine development now has longer timelines than airframe development and carries larger risks of product maturity problems.
To understand why engine development has become a challenging task, we need to understand engine fundamentals and the technologies used for these fundamentals.
We have covered the problem areas of (Figure 1) compression in the compressor and combustion. Now, we look at the power-generating section, the turbines.
Figure 1. The gas turbine cycle and its parts. Source: Rolls-Royce: The Jet Engine.
Bjorn’s Corner: New engine development. Part 18. Combustors.
By Bjorn Fehrm
August 2, 2024, ©. Leeham News: We do an article series about engine development. The aim is to understand why engine development now has longer timelines than airframe development and carries larger risks of product maturity problems.
To understand why engine development has become a challenging task, we need to understand engine fundamentals and the technologies used for these fundamentals.
We have covered the problem areas of (Figure 1) compression in the compressor and combustion, with its requirements on low Soot and NOx emissions. Now we look at how combustors are designed to achieve such low emissions.
Figure 1. The gas turbine cycle and its parts. Source: Rolls-Royce: The Jet Engine.
Rolls-Royce aims to shorten hydrogen program pace
By the Leeham News Team
July 25, 2024, © Leeham News, Farnborough Air Show: Rolls-Royce is calling in data specialists Tata Consultancy Services (TCS) to help speed up the development of its hydrogen program, with the help of quantum computing and generative artificial intelligence.
Rolls-Royce hydrogen testing at DLR, Cologne. Credit: Rolls-Royce
The partnership – announced this week at the Farnborough International Airshow – aims to significantly shorten the design time for new hydrogen-powered propulsion systems under development at Rolls-Royce facilities.
The environmental benefits of hydrogen are gaining increased attention and have been front and centre at this year’s airshow. Hydrogen forms a central plank of the Rolls-Royce alternative fuels program.
Anupam Singhal, president of the TCS manufacturing division, told LNA the rationale for the collaboration with the engine manufacturer was bringing proven hydrogen-powered engine designs to market as quickly as possible.
“We have to look at all the tools and technologies available to us to make the entire ecosystem more sustainable,” he said. “Can we cut short the whole engine design time? Can we have this engine on the wing as quickly as possible?”
Under the expanded partnership, TCS will provide engineering skills and support for system design, component design, supply chain support, and program management to Rolls-Royce as it addresses three key challenges related to hydrogen: fuel combustion, fuel delivery, and fuel systems integration with an engine.
TCS has been working with Rolls-Royce for more than a decade, including testing to demonstrate the integration of technologies required for 100% hydrogen fuel operation on a modified Pearl 15 engine. However, this new partnership is not tied to any one product and aims to streamline the Rolls-Royce development program across its various hydrogen research projects. Read more
Bjorn’s Corner: New engine development. Part 16. Compressor air use.
By Bjorn Fehrm
July 19, 2024, ©. Leeham News: We do an article series about engine development. The aim is to understand why engine development now has longer timelines than airframe development and carries larger risks of product maturity problems.
To understand why engine development has become a challenging task, we need to understand engine fundamentals and the technologies used for these fundamentals.
We have covered the problem areas of a compressor and how these achieve power-to-air-pressure conversion efficiencies of over 90% by using advanced 3D airflow modeling. Now, we look at the users of the air from the engin’s compressor.
Figure 1. The gas turbine cycle and its parts. Source: Rolls-Royce: The Jet Engine.
To what extent can the A321XLR replace the Boeing 757, Part 3
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By Bjorn Fehrm
July 11, 2024, © Leeham News: We are comparing the Airbus a321XLR to the Boeing 757 to understand to what extent it can replace the 757 on the longer routes it operates for major airlines like United, American, and Delta.
We have looked at the development and operational history of the aircraft, their Apples-to-Apples capacity and range. Now, we use Leeham’s Aircraft Performance and Cost Model (APCM) to compare the operational costs of the aircraft.
Summary:
- The Boeing 757-200 has the same passenger capacity as the A321LR/XLR and a larger cargo capacity.
- Its range can compete with the A321LR but not the XLR. Both beat the 757 on operational economics.
Bjorn’s Corner: New engine development. Part 14. The compressor problems.
By Bjorn Fehrm
July 5, 2024, ©. Leeham News: We do an article series about engine development. The aim is to understand why engine development now has longer timelines than airframe development and carries larger risks of product maturity problems.
To understand why engine development has become a challenging task, we need to understand engine fundamentals and the technologies used for these fundamentals.
We covered the basics of how a compressor works last week. Now, we look at the challenges in compressor design (there are plenty).
Figure 1. The gas turbine cycle and its parts. Source: Rolls-Royce: The Jet Engine.
Bjorn’s Corner: New engine development. Part 13. The compressor.
By Bjorn Fehrm
June 28, 2024, ©. Leeham News: We do an article series about engine development. The aim is to understand why engine development now has longer timelines than airframe development and carries larger risks of product maturity problems.
To understand why engine development has become a challenging task, we need to understand engine fundamentals and the technologies used for these fundamentals.
We have covered the need for the axial speed of the core air to decrease and increase depending on the needs of the core engine’s sections. Now, we will start to look at the different parts of the core in more detail. We start with the compressor.
Figure 1. The gas turbine cycle and its parts. Source: Rolls-Royce: The Jet Engine.