Leeham News and Analysis
There's more to real news than a news release.
Bjorn’s Corner: Sustainable Air Transport. Part 36. Battery Management.
By Bjorn Fehrm
September 9, 2022, ©. Leeham News: Over the last weeks, we have discussed the cells that make up the battery system for an eVTOL.
The battery system has 10,000 cells or more. All these must, on an individual level, be managed to ensure they operate inside their allowed values. The Battery Management System, BMS, has this responsibility. It’s one of the most critical safety systems in an eVTOL.
Figure 1. The Battery Management System and battery packs from EP Systems. Source: EP Systems.
ICAO report outlines steps to reduce aviation’s carbon output
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By BRYAN CORLISS
Sept. 5, 2022, © Leeham News: Saying the climate crisis now is at “Code Red for Humanity,” the UN-sponsored International Civil Aviation Organization is calling on nations and companies to increase their investments toward techniques and technologies that can reduce aviation’s climate impact.
It won’t be easy, ICAO said in its Environmental Report 2022, which was released in July.
The aviation industry will be one of the hardest to ween off carbon-based forms of energy, a recent report concluded.
“Scaling the production of sustainable aviation fuels (SAF) and other energy sources requires substantial investment and financial support from both fuel suppliers and governments on top of what would be needed for associated infrastructural changes,” the report said. “This is particularly important, considering that the drop-in fuels have the largest potential to reduce the overall emission from international aviation by 2050.”
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Bjorn’s Corner: Sustainable Air Transport. Part 35. Lilium battery cells.
By Bjorn Fehrm
September 2, 2022, ©. Leeham News: This is a summary of the article Part 35P, Lilium battery cells.
It discusses the requirement the Lilium jet principle puts on its battery cells and how this is solved, both with a slightly different cell type and with some operational adaptations.
Figure 1. The final Lilium VTOL configuration with 30 jets. Source: Lilium.
Bjorn’s Corner: Sustainable Air Transport. Part 35P. Lilium battery cells. The deeper discussion.
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September 2, 2022, ©. Leeham News: This is a complementary article to Part 35, Lilium battery cells. It discusses the requirement the Lilium jet principle puts on its battery cells and how this is solved, both with a modified cell type and with some operational adaptations.
Bjorn’s Corner: Sustainable Air Transport. Part 33P. eVTOL batteries. The deeper discussion.
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August 19, 2022, ©. Leeham News: This is a complementary article to Part 33, eVTOL batteries. It discusses the trickiest system on an eVTOL, the battery system.
While Lithium Ion batteries have come a long way since the electric flight ideas took off in 2015, the battery system is still the biggest challenge for eVTOL designers, not only for total energy content but for a range of parameters.
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 32. Mixed architectures, Part 2.
August 12, 2022, ©. Leeham News: Last week, we looked at two eVTOLs that don’t fit the terminology we use; Multicopters, Vectored thrust, or Lift and Cruise, the Vertical VX4, and the Archer Maker. We look at Airbus’ CityAirbus NG this week, a Lift and Cruise design like no other (Figure 1).
Figure 1. The Airbus CityAirbus NG. Source: Airbus.
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.
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.