Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- RTX Q1 2025 Earnings: GTF Talk Takes A Back Seat To Tariffs April 22, 2025
- Tariffs Tumult Takes Over GE Aerospace Q1 2025 Earnings Call April 22, 2025
- Boeing reports mixed results of latest employee survey, but middle management and officers remain key obstacles April 22, 2025
- Hopes for 1Q financial progress turns into bumpy ride for Boeing April 21, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 18. April 18, 2025
Bjorn’s Corner: Sustainable Air Transport. Part 42. eVTOL range.
By Bjorn Fehrm.
October 21, 2022, ©. Leeham News: This is a summary of the article Part 42P, eVTOL range. It discusses the range of a typical eVTOL flying a feeder mission from a city center to an airport.
The 42P article details the energy consumption for each stage in the mission and the range we fly. We summarize the results here.
Figure 1. The Vertical Aerospace VX4 in an early rendering with similar looks to the eVTOL we discuss. Source: Vertical Aerospace.
Bjorn’s Corner: Sustainable Air Transport. Part 42P. eVTOL mission range. The deeper discussion.
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October 21, 2022, ©. Leeham News: This is a complementary article to Part 42, eVTOL mission range. It discusses the typical maximum range we can expect from a certified eVTOL by mid-decade.
We have described the vehicle and the mission data in the three previous Corners; now, we analyze the energy consumption for the mission and discuss the range we can achieve.
Bjorn’s Corner: Sustainable Air Transport. Part 33. eVTOL batteries.
August 19, 2022, ©. Leeham News: This is a summary of article Part 33P, eVTOL batteries. This article discusses the trickiest system on an eVTOL, the battery system.
The battery system supplies the energy to the VTOL, and given today’s and tomorrow’s battery technology; it’s a tight resource that needs a lot of pampering.
Figure 1. We use graphs in the Pipistrel spare parts catalog to show the battery system of the Pipistrel Velis Electro. Source: Pipistrel and Leeham Co.
Bjorn’s Corner: Sustainable Air Transport. Part 31. Mixed architectures.
By Bjorn Fehrm
August 5, 2022, ©. Leeham News: This week, we look at two eVTOLs that don’t fit the terminology we use; Multicopters, Vectored thrust, or Lift and Cruise. The Vertical VX4 and Archer Maker are Lift and Cruise designs, but they use vectored thrusters for the cruise thrust, Figure 1.
Figure 1. The Vertical VX4. Source: Vertical Aerospace.
Airbus prepares contrail flight tests
July 21, 2022, © Leeham News at Farnborough Air Show: Airbus is converting two Arcus high-altitude gliders to check if the contrails produced by hydrogen combustion engines create an environmental problem.
The background is that experts can’t agree if the water vapor produced by hydrogen combustion (which merges hydrogen with oxygen to water) can cause global warming or not. The only way to resolve the dispute and gain fundamental knowledge is to fly and measure.
Figure 1. First flight with the Blue Condor program’s test aircraft. Source: Airbus.
Bjorn’s Corner: Sustainable Air Transport. Part 27. Multicopters.
July 8, 2022, ©. Leeham News: We will start the analysis of the market’s most prominent VTOL variants by looking at the simplest version, multicopters.
When we analyze the multicopters, we can go through some fundamentals of how VTOL operates and the technology used.
Figure 1. The VoloCity multicopter of the Volocopter company. Source: Volocopter.
Bjorn’s Corner: Sustainable Air Transport. Part 26. VTOLs.
By Bjorn Fehrm
July 1, 2022, ©. Leeham News: Last week, we finished our discussions around Fuel Cell-based airliners using hydrogen as fuel.
We could see the technology has true zero emissions, but the maturity of the many parts needed (hydrogen tank and fuel system, multi-MegaWatt class aeronautical fuel cells, motors, and controls) are not there. We are in the crawling before walk stage with sub-MegaWatt systems to make their first flights over the next years.
Another area claiming Green credentials is the VTOL space. Because these are based on electric technology, VTOLs are claimed as environmentally friendly and a good way to transport people.
We will analyze this industry and its claims of being an efficient, environmentally friendly way of transportation.
Figure 1. Joby S4, the VTOL project that has come the furthest. Source: Joby Aviation.
Bjorn’s Corner: Sustainable Air Transport. Part 25. High Temperature Fuel Cell-based 70-seat airliner
By Bjorn Fehrm
June 24, 2022, ©. Leeham News: Last week, we discussed how a High Temperature Fuel Cell (HTFC) could improve the installation of a propulsion system in our 70-seat airliner. We now add this variant to the systems we examined for installation effects and efficiencies.
The deeper discussion is in the sister article, Part 25P. High Temperature Fuel Cell-based 70-seat airliner.
Figure 1. The ATR 72-600 70-seater turboprop. Source: ATR.
Bjorn’s Corner: Sustainable Air Transport. Part 25P. High Temperature Fuel Cell-based 70-seat airliner. The deeper discussion.
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June 24, 2022, ©. Leeham News: This is a complementary article to Part 25, High Temperature Fuel Cell-based 70-seat airliner. It adds the masses and efficiencies of a High Temperature Fuel Cell system to our 70-seat airliner fuel cell variants.
Bjorn’s Corner: Sustainable Air Transport. Part 24. High Temperature Fuel Cells
By Bjorn Fehrm
June 17, 2022, ©. Leeham News: Last week, we looked at the installation effects and efficiencies of the fuel cell systems we discussed in earlier parts of the series.
We could see the variants were significantly heavier than the propulsion system they would replace for an ATR72 size aircraft. The discussion assumed classical PEM fuel cells, also called Low Temperature PEM Fuel Cells. Now we look at if High Temperature PEM Fuel Cells can improve the installation situation.
Figure 1. The ATR 72-600 70-seater turboprop. Source: ATR.