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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.
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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.
July 7, 2023, ©. Leeham News: We explore different technologies in the series that can make our next-generation airliners more efficient and, thus, less polluting.
We have discussed developments of engine and airframe technologies, such as Turbofans versus Open Rotors and different airframe configurations to minimize drag and, thus, energy consumption.
When utilizing these developments to increase efficiency we must fly the aircraft in a different way depending on the technology.
And how we fly the aircraft is not only influenced by the factors we have discussed. We must consider factors at the airplane level, at the airliner operational level, and finally, at the airline fleet level.
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By Bjorn Fehrm
July 6, 2023, © Leeham News: In our series on costs factors that make up Cash Operating Cost for a battery-based airliner with range extenders, we now add Crew costs and Airport/Airway fees.
We then have all the components of the Cash Operating Cost (COC) for the ES-30 and can compare it to a normal propulsion 30-seat turboprop.
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By Bjorn Fehrm
June 29, 2023, © Leeham News: In our series on fundamental costs factors that make up Cash Operating Cost, COC (Fuel, Maintenance, Airway/Airport fees, Crew costs) for new Green airliners, we have analyzed the energy costs and now move on to the maintenance costs.
For a battery-based airliner with range extenders, it’s a complex mix of battery and gas turbine costs.
Figure 1. The Heart Aerospace ES-30 hybrid 30-seat airliner. Source: Heart Aerospace.
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By Bjorn Fehrm
June 22, 2023, © Leeham News: Every announcement from aircraft deals, OEM updates, or supply chain news now has the words Sustainable/Sustainability injected in every second sentence. It doesn’t matter what the subject is; if it’s about a gas-guzzling way of transporting people at supersonic or even hypersonic speeds or at the other end in an eVTOL which is only as fast as your car on a US highway.
What is the real news about making our air transport system less polluting behind this misuse of the buzzwords? You have to search behind the headlines and the announcements that you know will not turn the dial. Let’s tour the Paris Air Show 2023 and look at the real developments in Sustainability.
Figure 1. First flight of Universal Hydrogen’s DH8-300 with a hydrogen propulsion system on the starboard side. Source: Universal Hydrogen.
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By Bjorn Fehrm
June 15, 2023, © Leeham News: In our series on fundamental costs factors that make up Cash Operating Cost, COC (Fuel, Maintenance, Airway/Airport fees, Crew costs), we have started analyzing if the size related cost factors also apply to green propulsion airliners and if the trends stay the same or change.
We use the Heart Aerospace ES-30 project as an example of a battery-based airliner with range extenders. Last week we developed the fundamental aero data for the aircraft with our Aircraft Performance and Cost model; now, we fly representative sectors and look at the energy and fuel consumptions compared to a similar-sized turboprop airliner.
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By Bjorn Fehrm
June 8, 2023, © Leeham News: We have analyzed the costs factors that make up Cash Operating Cost, COC (Fuel, Maintenance, Airway/Airport fees, Crew costs), and how these vary with different size airliners. The aim was to search for fundamental trends and if these disadvantaged a smaller airliner versus a larger one.
We found that a smaller airliner (we analyzed from 190 seats down to 9 seats) has structural cost disadvantages versus a larger model. The analysis was made with conventional gas turbine-propelled planes so as not to complicate the work. Now we introduce airliner types with green propulsion concepts and see if the trends stay the same or change.
May 26, 2023, ©. Leeham News: This is a summary of the article Part 14P. Airframe for lower friction drag. The article discusses in detail a Blended Wing Body (BWB) type airframe and how it reduces the wetted area and, thus, air friction drag compared to a conventional tube and wing airframe.
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By Bjorn Fehrm
May 26, 2023, ©. Leeham News: This is a complementary article to Part 14. Airframe for lower friction drag. It discusses in detail the Blended Wing Body (BWB) type of airframe that shall reduce the airframe wetted area and thus air friction drag.