Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- Better transparency needed on Boeing’s 1Q earnings call April 22, 2024
- Bjorn’s Corner: New engine development. Part 4. Propulsive efficiency April 19, 2024
- Boeing unlikely to meet FAA’s 90-day deadline for new safety program April 18, 2024
- Focus on quality not slowing innovation, says GKN April 18, 2024
- Boeing defends 787, 777 against whistleblower charges April 17, 2024
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 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.
Bjorn’s Corner: New aircraft technologies. Part 10. Engine choice
By Bjorn Fehrm.
April 28, 2023, ©. Leeham News: This is a summary of the article New aircraft technologies. Part 10P. Engine choice. The article discusses the engine architecture choices that must be made when developing the next-generation airliners.
Figure 1. The Pratt & Whitney high bypass geared turbofan technologies. Source: Pratt & Whitney.
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.
Bjorn’s Corner: New aircraft technologies. Part 3P. Airframe improvements
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By Bjorn Fehrm
March 10, 2023, ©. Leeham News: This is a complementary article to New aircraft technologies. Part 3. Airframe improvements. It discusses in detail the areas of an airliner airframe where tangible improvement can be made to make it more efficient and thus lower cost combined with less Green-House-Gas (GHG) emissions.
Bjorn’s Corner: New aircraft technologies. Part 2. Target markets.
March 3, 2023, ©. Leeham News: We started a series last week that will look at what environmental and air traffic economy improvements we can get with traditional aeronautical technology developments.
Before we look at technology, we must define what air transport market has the highest impact from changes. Useful technology developments are not necessarily the same for Regional, Narrowbody, or Widebody aircraft.
Figure 1. The distribution of Available-Seat-Kilometer by airplane type 2019. Source: JADC.
Bjorn’s Corner: Aircraft technology developments. Part 1.
By Bjorn Fehrm
February 24, 2023, ©. Leeham News: In the Sustainable Air Transport series we finished last week, we described new aircraft technologies developed to reduce Green House Gas (GHG) emissions.
There was one area we didn’t discuss, the progress on conventional technologies to reduce the fuel burn of an airliner.
We now start a series, digging deeper into what we can do with conventional technologies to reduce the fuel burned per passenger kilometer and, thus, GHG emissions.
Figure 1. Truss braced wing, a way to reduce aircraft drag. Source: Boeing.