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 19. April 25, 2025
- How good is the C929? Part 2. April 24, 2025
- Boeing First Quarter Results Update: China is 10% of the backlog, with 500 in “Unidentified” April 24, 2025
- Boeing First Quarter Results: Tariffs, Return flights, $10.55bn asset sale April 23, 2025
- RTX Q1 2025 Earnings: GTF Talk Takes A Back Seat To Tariffs April 22, 2025
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.
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 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.
The Small Airliner problem, Part 2
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By Bjorn Fehrm
April 27, 2023, © Leeham News: We started a series about the viability of the business plans for small airliners (nine to 50 seats) last week in the light of a continuing decline of regional airlines in the US and Europe.
To understand whether fundamentals are stacked against small airliners, we look at operational cost factors and how these scale with aircraft size. Then we add the revenue and yield and discuss the conditions for viable business plans for different size aircraft.
This week we use the Leeham airliner performance and cost model to compare the airframe energy and fuel consumptions for airliners spanning nine to 200 seats.
Figure 1. Eviation Alice is a battery-based nine-seat electric aircraft. Source: Eviation.
Summary:
- On an airframe energy level, a smaller airliner consumes more energy per transported passenger than a larger one.
- If we change the metric to propulsion energy consumption, the trend is augmented as small propulsion solutions are less efficient than larger ones.
The Small Airliner Problem
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By Bjorn Fehrm
April 20, 2023, © Leeham News: New Sustainable aircraft projects, for economical reasons, target small airliner types as first projects and then, after proving the concept, to move up in size. The number of 9-seat, 19-seat, and 30- to 50-seat upstarts announced over the last years must be in the hundreds.
They all claim major advances in environmentally friendly propulsion and that their first aircraft have viable business models. In their business plans, there are elaborate explanations why local air services will flourish through the introduction of small, environmentally friendly aircraft.
The reality is another. The airliner size, where more than 100 aircraft per year are delivered, is 200 seats increasing, and sales below 50 seats have slowed to a trickle. ATRs, the leading supplier of airliners below 70 seats, delivered five 50-seater turboprops during 2022 out of a total of 29. The 50-seater model stayed at around 10% of deliveries between 2014 to 2019 before COVID, when total production was 70 to 80 turboprops per year.
There are economic reasons for these low numbers, and these are not changing for the better. We will explore these reasons using our airliner Performance and Cost model in a series of articles, where we compare operational costs for 9-, 19- and 50-seaters to the larger aircraft.
Figure 1. The latest small airliner project from Maeve Aerospace. A 50-seater battery-based electric aircraft. Source: Maeve Aerospace.
Summary:
- We show the cost factors and their proportions for different airliner sizes.
- Then we look at how these factors scale with aircraft size.
The production cost trap for eVTOL upstarts
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By Bjorn Fehrm
April 13, 2023, © Leeham News: Last week, we gave the example of a new propulsion principle 30-seat airliner as a project that would face the liquidity strain of initial production costs. We continue today with a look at the leading eVTOL projects, where development costs are passing $1bn and growing.
What will be the cash burn before these projects generate positive cash flow from serial production sales and services? We use our production cost model to analyze the situation.
Figure 1. Our generic eVTOL uses an early rendering of the Vertical VX4 as an illustration. Source: Vertical Aerospace.
Summary:
- VTOL projects promise early payback of invested capital.
- Our production cost model says otherwise.
Bjorn’s Corner: Sustainable Air Transport. Part 58. Summary Part 2.
By Bjorn Fehrm
February 17, 2023, ©. Leeham News: Last week, we summarized that SAF is the short-term solution for GreenHouse Gas (GHG) reduction for Air Transport, and hydrogen is the longer-term solution for up to medium-haul flights.
What about battery and hybrid aircraft? It’s the go-to solution for ground transport (except for long-haul trucks, which are going hydrogen, Figure 1)?
Figure 1. Mercedes hydrogen truck from the world’s largest truck maker. Source: Daimler trucks.
Bjorn’s Corner: Sustainable Air Transport. Part 57. Summary
By Bjorn Fehrm
February 10, 2023, ©. Leeham News: We started the present series around Sustainable Air Transport on the 7th of January 2022, more than a year ago. During this time, we have covered a lot of subjects regarding the emissions from Air Transport.
It’s time to wrap up the series and summarize what we covered and learned.
Figure 1. Our energy consumption and where it’s coming from. Source: Our World in Data.