Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- The BWB has a long way to go before flying passengers, freight May 12, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 21. May 9, 2025
- Does an A220-500 need a new wing and engines? Part 2. May 8, 2025
- Embraer downplays tariff impact on 2025 results May 6, 2025
- JetZero readies effort for private equity fund raising May 5, 2025
The reality behind the eVTOL industry’s hyperbole, Part 6.
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By Bjorn Fehrm
August 17, 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 production.
We used our Aircraft Performance and Cost model to understand the data for the typical missions for the Joby S4 and Archer Midnight VTOLs and how the economics pans out for these missions. We now look at the results and compare them to what’s been projected from the OEMs.
Figure 1. The Joby S4 VTOL. Source: Leeham Co.
Summary:
- We found the VTOL OEM’s economics for the typical 10-minute shuttle flights optimistic.
- When we go back and look at investor deck projections, the cost comparison to helicopter costs were totally off the mark. When we correct this the VTOL is more expensive to operate then an equivalent helicopter.
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.
Bjorn’s Corner: New aircraft technologies. Part 24. Single or dual aisle fuselage?
By Bjorn Fehrm.
August 4, 2023, ©. Leeham News: This is a summary article to Part 24P. Single or dual aisle fuselage. It summarizes the drag and weight simulations we have done on fuselages for the next generation Heart of the Market airliners. When it comes to drag and weight for a 250-seat airliner that shall replace today’s Single Aisle, is a Single Aisle fuselage lower in drag and weight than a Dual Aisle fuselage?
Figure 1. The drag components of a Single Aisle airliner at 35kft and M0.78. Source; Leeham Co.
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.
Bjorn’s Corner: New aircraft technologies. Part 23. Efficient flight speeds
By Bjorn Fehrm
July 28, 2023, ©. Leeham News: We touched on efficient flight speeds in Part 21, but it was focused on fuel efficiency and how new technologies require the airliner to fly at new altitude-speed combinations to maximise the fuel efficiency gains.
We now look at how to fly the airliner cost-efficiently, which is slightly different from how to fly it fuel efficiently.
Figure 1. The difference between lowest fuel burn speed (Mmr) and long-range cruise speed Mlrc. Source: Airbus.
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.
Bjorn’s Corner: New aircraft technologies. Part 22. Engine characteristics.
By Bjorn Fehrm
July 21, 2023, ©. Leeham News: Developments in engines and airframe technologies require that future airliners are flown differently to maximize the technology benefit.
After looking at the consequences of new developments for the airframe, we now analyze what engine developments mean for how they will be sized and flown.
Figure 1. The RISE engine from CFM. Source: CFM.
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.
Bjorn’s Corner: New aircraft technologies. Part 21. Changed flight profiles
By Bjorn Fehrm
July 14, 2023, ©. Leeham News: Developments in engines and airframe technologies require that the aircraft are flown differently to maximize the benefits.
We start by locking what changes in parasitic and induced drag mean for how airliners fly.
Figure 1. A Truss Braced Wing airliner shall fly higher. Source: Boeing.