Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- Boeing reports mixed results of latest employee survey, but middle management and officers remain key obstacles April 22, 2025
- Hopes for 1Q financial progress turns into bumpy ride for Boeing April 21, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 18. April 18, 2025
- Natilus: Composite BWB, entry-into-service by 2029, 570 on order April 17, 2025
- China bans Boeing, US parts imports in tariff war April 15, 2025
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 15. Airframe for lower Induced drag
By Bjorn Fehrm
June 1, 2023, ©. Leeham News: Last week, we examined ways to lower the dominant drag of an airliner, the air friction drag (Figure 1).
Now we look at the second largest drag component, the Induced drag, and how it can be reduced. We go through the fundamentals of the drag to understand how to affect it. Then we look at aircraft changes to reduce Induced drag and if these make sense on an overall aircraft efficiency level.
Figure 1. The drag components on a typical single-aisle airliner at cruise. Source: Leeham Co.
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 6
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By Bjorn Fehrm
May 25, 2023, © Leeham News: In our series about the viability of the business plans for small airliners (nine to 50 seats), we have covered the cost factors that make up the Cash Operating Cost, COC (Fuel, Maintenance, Airway/Airport fees, Crew costs).
We now compile the Cash Operating Cost for the aircraft on a typical sector and discuss the result.
Figure 1. The D238eco 40-seat airliner. Source: Deutsche Aircraft.
Summary:
- The Cash Operating Costs do not reduce in proportion to passenger numbers for a smaller airliner.
- As a consequence, a small airliner needs a higher load factor or yield to be viable.
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.
Bjorn’s Corner: New aircraft technologies. Part 12. Airframe efficiency improvement
By Bjorn Fehrm
May 12, 2023, ©. Leeham News: This is a summary of the article New aircraft technologies. Part 12P. Airframe efficiency improvement. The article discusses the different drag types that affect an airframe, their magnitudes, and the physics behind them. Airframe efficiency improvements are about reducing these drags.
Figure 1. The drag types that affect our single-aisle airliners. Source: Leeham Co.
Bjorn’s Corner: New aircraft technologies. Part 12P. Airframe efficiency improvement
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By Bjorn Fehrm
May 12, 2023, ©. Leeham News: This is a complementary article to Part 12. Airframe efficiency improvement. It discusses in detail the next-generation airframe improvements we can expect. We start with detailing the size of airframe inefficiency for today’s airframes, then look at the areas we can improve.
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 11. Airframe.
By Bjorn Fehrm
May 5, 2023, ©. Leeham News: In our series on the different technologies available when developing next-generation airliners, we have covered the fuselage configuration and engine options.
Now we turn to airframe technologies. We will look at different airframe architectures, their advantages, and disadvantages. To support the discussion, we will model the different variants in our Airliner Performance and Cost model to understand their characteristics.
Figure 1. The Boeing truss-braced wing is a candidate for the next Heart of the Market airliner. Source: Boeing.