Bjorn’s Corner: New aircraft technologies. Part 9P. Engine core advances

Subscription required

By Bjorn Fehrm

April 21, 2023, ©. Leeham News: This is a complementary article to Part 9. Engine core advances. It discusses in detail the next-generation propulsion system cores and what efficiency improvements to expect from different technological advancements.

Read more

The Small Airliner Problem

Subscription required

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.

Read more

Bjorn’s Corner: New aircraft technologies. Part 8. Propulsion advances

By Bjorn Fehrm

April 14, 2023, ©. Leeham News: This is a summary of the article New aircraft technologies. Part 8P. Propulsion advances. The article discusses how developing the next-generation airliner propulsion system will be the second most important area after we decide on the fuselage type and what to expect from increases in Propulsive efficiency.

Figure 1. The Ultrafan demonstrator readied for tests, with its 140-inch fan giving a bypass ratio of 16:1. Source; Rolls-Royce.

Read more

Bjorn’s Corner: New aircraft technologies. Part 8P. Propulsion advances

Subscription required

By Bjorn Fehrm

April 14, 2023, ©. Leeham News: This is a complementary article to Part 8. Propulsion advances. It discusses in detail the next-generation propulsion and what efficiency improvements to expect from different technological advancements.

Read more

The production cost trap for eVTOL upstarts

Subscription required

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.

Read more

Bjorn’s Corner: New aircraft technologies. Part 7. Propulsion

By Bjorn Fehrm

April 7, 2023, ©. Leeham News: This is a summary of the article New aircraft technologies. Part 7P. Propulsion. The article discusses how developments in the next-generation airliner propulsion system will be the second most important area for improved efficiency and lower emissions after we have decided on the fuselage type.

Figure 1. The CFM LEAP engine gained 15% efficiency compared to the engine it replaced, the CFM56. Source: CFM.

Read more

Bjorn’s Corner: New aircraft technologies. Part 7P. Propulsion

Subscription required

By Bjorn Fehrm

April 7, 2023, ©. Leeham News: This is a complementary article to Part 7. Propulsion. It discusses in detail the next-generation propulsion systems and what to expect from their possible increase in performance and efficiency.

Read more

The production cost trap for upstarts

Subscription Required

By Bjorn Fehrm

April 6, 2023, © Leeham News: The last five years have been among the busiest in aeronautical history, with announcements of new aircraft and VTOLs based on greener propulsion technologies. The public focus has been on the hurdle for these projects to achieve regulator certification, how long this will take, and how much it will cost. We have hundreds of experts publishing articles on the subject.

But there is another hurdle as large as certification for these projects: the initial production cost. It’s just that the knowledge about this more difficult-to-understand phase is poor among the experts. But, looking at history, the majority of new airliner entrants die during early production, not during development.

Why? We use our production cost model to explain.

Figure 1. Heart Aerospace ES-30; a typical startup project. Source: Heart Aerospace.

Summary:

• Startup projects fight to get the investments for development.
• Little do they know this is only halfway to success.

Read more

Bjorn’s Corner: New aircraft technologies. Part 6. Fuselage manufacturing

By Bjorn Fehrm

March 31, 2023, ©. Leeham News: This is a summary of the article New aircraft technologies. Part 6P. Fuselage manufacturing. The article discusses how a non-circular cross-section drives material use towards composites and the difficulties of manufacturing aeronautical composite structures in high volumes.

Figure 1. The elliptical NMA cross-section compared with A321 and 767 cross-sections. Source: Leeham Co.

Read more

Bjorn’s Corner: New aircraft technologies. Part 6P. Fuselage manufacturing

Subscription required

By Bjorn Fehrm

March 31, 2023, ©. Leeham News: This is a complementary article to Part 6. Fuselage manufacturing. It discusses in detail how to manufacture a non-circular fuselage that avoids fatigue problems.

Read more