Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- China bans Boeing, US parts imports in tariff war April 15, 2025
- Boeing welcomes COMAC competition as Asia-Pacific demand soars April 15, 2025
- How good is the C929? April 14, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 17. April 11, 2025
- Uncertainty plagues airline, aerospace, lessor industries over tariffs April 10, 2025
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.
Bjorn’s Corner: New engine development. Part 28. Wrapup.
By Bjorn Fehrm
October 11, 2024, ©. Leeham News: We have done an article series on why engine development takes longer than airframe development. Part of the reason is that advancements in engine technology can deliver considerably higher fuel consumption reductions than airframe advancements.
The change of engines for the A320 series and 737 MAX delivered a 15% improvement in engine efficiency. In contrast, the airframe improvement was less than half, mainly by stacking cabin seats closer together.
Figure 1. The 4:1 gear ratio Utrafan demonstrator in the Rolls-Royce test cell. Source: Rolls-Royce.
Bjorn’s Corner: New engine development. Part 26. New versus old, Trent 1000 vs. XWB
By Bjorn Fehrm
September 27, 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.
In our look at examples of recent developments with problems and these put in a historical perspective, looking at the reliability and durability of its predecessor we compare the Rolls-Royce Trent 1000 for the Boeing 787 to the Trent XWB for the Airbus A350.
Figure 1. The Rolls-Royce Trent 1000 with its wide cord hollow titanium fan. Source: Rolls-Royce.
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 25. New versus old, CFM56 vs. LEAP
By Bjorn Fehrm
September 20, 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.
In our look at examples of recent developments with problems and these put in a historical perspective, we compare the CFM56 to the LEAP, comparing their reliability and durability.
Figure 1. The CFM56 with its mid-span shrouded titanium fan. Source: CFM.
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 23. Development risks.
By Bjorn Fehrm
September 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 have covered the parts of an engine that involve challenging technology and which decide its reliability (dispatch consistency) and durability (time on wing). Now, we discuss why modern engine design is more challenging regarding these parameters than airframe design.
Figure 1. The Pratt & Whitney GTF in cross-section, one of the new engines. Source: Pratt & Whitney.
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 21. The High Turbine.
August 23, 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. We discuss why.
In our journey through an engine, we have reached the turbine part, where we will dig deeper into the high-pressure turbine. This is the most stressed part of the engine and has a major influence on engine performance and durability.
Figure 1. Our example engine, the LEAP-1A cross-section with the high-pressure turbine marked. Source: CFM.
Bjorn’s Corner: New engine development. Part 20. Temperatures.
By Bjorn Fehrm
August 16, 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 different areas of a gas turbine except the exhaust (Figure 1). Before we go to the exhaust and the different outputs from a gas turbine Core, we look at the temperatures and how to cope with them in the different sections of a gas turbine.
Figure 1. The gas turbine cycle and its parts. Source: Rolls-Royce: The Jet Engine.