Leeham News and Analysis
There's more to real news than a news release.
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?
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.
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 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.
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.
Bjorn’s Corner: New engine development. Part 10. Airframe integration
By Bjorn Fehrm
May 24, 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.
In the last Corner, we looked at the nacelles used for a turbofan engine and for an open-rotor engine. Now, we go one step further and look at the integration of modern engines on an airliner.
Figure 1. Boeing 737NG (left) and MAX (right) nacelles compared. Source: Leeham Graphic from Boeing 737 images.
Airbus’ A350-1000 or Boeing’s 777-8? Part 1
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By Bjorn Fehrm
May 9, 2024, © Leeham News: We are doing an article series comparing the capabilities of the Airbus A350-1000 and the Boeing 777X series. We started with the 777-9, the larger model. Now, we continue with the shorter 777-8, an aircraft closer in size to the A350-1000.
The 777-8 was originally launched in a shorter version together with the 777-9. Then, it went very quiet around the 777-8, with some analysts speculating that the passenger version would not be done. The 777X freighter, the 777-8F, was launched in January 2022. It became a bit longer than the 777-8. This now forms the final definition of the 777-8.
Summary:
- The comparison of the A350-1000 and the 777-8 is comparing the longer-narrower versus the shorter-wider.
- Which is the best? We use Leeham’s Aircraft Performance and Cost Model (APCM) to find out.
A350-1000 or 777-9? Part 4
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By Bjorn Fehrm
May 2, 2024, © Leeham News: We are doing an article series comparing the capabilities of the Airbus A350-1000 and the Boeing 777-9. We looked at the development history of the aircraft and then their capability and fuel economics.
We could see that the 777-9 is trailing the A350-1000 in payload range, partly because we compare the base version of the 777-9 with a further developed A350-1000. Now, we investigate what the 777-9 performance would be should we include a typical future development of the Maximum TakeOff Weight (MTOW).
Summary:
- The A350-1000 has a clear payload-range advantage over the standard 777-9.
- With an in-service Maximum TakeOff Weight (MTOW) development like the A350-1000, the difference is reduced.
A350-1000 or 777-9? Part 3
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By Bjorn Fehrm
April 25, 2024, © Leeham News: We are doing an article series comparing the capabilities of the Airbus A350-1000 and the Boeing 777-9. We looked at the development history of the aircraft and compared their size and payload capacity.
Now, we use our Aircraft Performance and Cost Model (APCM) to fly the aircraft on a typical route and compare their performance. We also look at their stage of development and the potential for future upgrades inherent in the design.
Summary:
- The A350-1000 has got its Maximum TakeOff Weight (MTOW) increased four times since entry into service.
- The latest MTOW hike to 322t gives the A350 a clear payload-range advantage over the 777-9. Any increase in the 777-9’s MTOW will have to come after type certification.