Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- Bjorn’s Corner: Air Transport’s route to 2050. Part 24. May 30, 2025
- Does an A220-500 need a new wing and engines? Part 3. May 29, 2025
- Boeing’s future depends on FAA approvals May 26, 2025
- Updated, May 29, 2025: Department of Justice, Boeing OK to Non-Prosecution Agreement May 23, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 23. May 23, 2025
The Small Airliner Problem, Part 10. Cash costs for a battery-based airliner
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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.
Figure 1. The Heart Aerospace ES-30 hybrid 30-seat airliner. Source: Heart Aerospace.
Summary:
- The high operating weight and slow speed of a battery airliner increase the Airport/Airway fees and Crew costs for the ES-30.
- In summary, only one Cash cost remains competitive, and the COC total exceeds the cost of a 30-seater turboprop.
The Small Airliner Problem, Part 9. Maintenance costs for battery airliners with range extenders
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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.
Summary:
- The maintenance costs for a battery-based airliner are high. It’s the batteries that cost, not the electric motors.
- Adding range extenders complicates the propulsion system and adds further costs.
What’s the Green aviation news at Paris 2023?
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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.
Summary:
- The waves of Green propulsion solutions with inflated claims have calmed down.
- It’s replaced with operationally usable solutions that deliver tangible emission gains.
The Small Airliner Problem, Part 8. A battery-based airliner
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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.
Figure 1. The Heart Aerospace ES-30 hybrid 30-seat airliner. Source: Heart Aerospace.
Summary:
- There is a difference between what the theory says about aircraft range on batteries and how you have to fly in practice to keep battery costs down.
- The ES-30 has dual range-extending Turbogenerators. They get going more often and at a shorter range than advertised.
The Small Airliner Problem, Part 7. How affected are Green airliners?
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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.
Figure 1. The Heart Aerospace ES-30 hybrid 30-seat airliner. Source: Heart Aerospace.
Summary:
- We analyze the fundamental characteristics of a hybrid 30-seat airliner and compare it to the conventional airliners we characterized in the series.
- The negative cost trend for smaller airliners worsens for a battery or hybrid airliner.
Bjorn’s Corner: New aircraft technologies. Part 14. Airframe for lower friction drag
By Bjorn Fehrm
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.
Figure 1. JetZero Z5 250 seat BWB jet concept. Source: JetZero.
Bjorn’s Corner: New aircraft technologies. Part 14P. Airframe for lower friction drag
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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.
The Small Airliner Problem, Part 5
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By Bjorn Fehrm
May 18, 2023, © Leeham News: In our series about the viability of the business plans for small airliners (nine to 50 seats), we have covered how energy/fuel consumption, maintenance, and airway/airport fees scales with the size of the airliner.
The cost factor we now examine is the crew cost, where especially the flight crew cost development is troublesome, as pilots changed jobs during the COVID lull or retired early. When air traffic now rebounds, the lack of pilots drives wages and thus costs to new record levels.
Figure 1. The Heart Aerospace 30-seat ES-30 electric airliner. Source: Heart Aerospace.
Summary:
- The availability of flight crews is a major problem in the US market. It will spread to other geographies as air traffic picks up after COVID-19.
- The scaling of crew costs per transported passenger is unfavorable for smaller aircraft.
The Small Airliner Problem, Part 4
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By Bjorn Fehrm
May 11, 2023, © Leeham News: In our series about the viability of the business plans for small airliners (nine to 50 seats), we have covered how energy/fuel consumption and maintenance scales with the size of the airliner.
The cost factor we examine today is the cost of using the airport and airways infrastructure. Airlines pay for landing plus parking at airports and for using their passenger facilities. The airlines also pay for using the Air Traffic Control (ATC) infrastructure when flying the routes.
Each airport and national airway system have their own fee structures. We check how these scale with aircraft size.
Figure 1. The TECNAM P2021 piston prop airliner is also offered in an electric version called P-Volt. Source: TECNAM.
Summary:
- Airway fees scale differently per transported passenger to the airport fees.
- Overall, airport and airway fees are not proportional to carried passengers on a route.
The Small Airliner Problem, Part 3
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By Bjorn Fehrm
May 4, 2023, © Leeham News: In our series about the viability of the business plans for small airliners (nine to 50 seats), we have covered how energy and fuel consumption scales with the size of the airliner.
The cost factor we examine today is the maintenance cost for keeping an airliner fit for purpose and safe.
We use the Leeham aircraft performance and cost model to get the data for the maintenance costs for airliners going from nine to 200 seats.
Figure 1. The Cessna Sky Courier is a new 19-seat small airliner with conventional propulsion. Source: Textron Aviation.
Summary:
- The maintenance costs of an airliner scale differently from the energy and fuel consumption we studied last week.
- We discuss the scaling metrics for the airframe maintenance costs and how these differ from what drives engine maintenance costs.