Bjorn’s Corner: New aircraft technologies. Part 31. Detailed design -3

By Bjorn Fehrm

September 22, 2023, ©. Leeham News: Last week, we discussed program management methods for the Detailed design phase of an airliner development program. While the modern Agile work methods suit smaller projects, the sheer size and complexity of an airliner project that involves hundreds of companies require more structured management methods with Agile used for areas where it’s suitable.

We now go a step deeper than program and configuration management and look at development techniques and tools for Detailed design.

Figure 1. The development plan for a new airliner. Source: Leeham Co.

Read more

Bjorn’s Corner: New aircraft technologies. Part 30. Detailed design -2

By Bjorn Fehrm

September 15, 2023, ©. Leeham News: Last week, we described the beginning of the Detailed design phase of an airliner development program. We discussed the importance of a good information set from Preliminary design, ideally as a collection of digital models forming a Preliminary level digital twin.

We now discuss how the work is managed in the Detailed design phase and how to speed up the work and make it more efficient.

Figure 1. The development plan for a new airliner. Source: Leeham Co.

Read more

Bjorn’s Corner: New aircraft technologies. Part 29. Detailed design

By Bjorn Fehrm

September 8, 2023, ©. Leeham News: We described the Preliminary design phase of an airliner development program over the last weeks. Now our project is transitioning into Detailed design.

It’s the most challenging part of the project as we now go from perhaps a thousand people involved at the OEM into tens of thousands and even more people at consultancies and suppliers.

 

Figure 1. A new airliner family development plan. Source: Leeham Co.

Read more

Bjorn’s Corner: New aircraft technologies. Part 28. Alternative Preliminary design

By Bjorn Fehrm

September 1, 2023, ©. Leeham News: We described the Preliminary design phase of an airliner development program last week. One could say this was the classical way that aircraft projects conduct Preliminary design.

There is a different way that Conceptual and Preliminary design can be run. It’s more along the lines of pre-development of functions, as a reader commented on two articles back.

Figure 1. An alternative new airliner family development plan. Source: Leeham Co.

Read more

Bjorn’s Corner: New aircraft technologies. Part 26. Airliner development program

By Bjorn Fehrm

August 18, 2023, ©. Leeham News: We started last week to look at how to make the development of a new airliner family more efficient.

First, we describe how development projects are phased and how many people with what competencies are engaged in each phase. Then we can start the discussion of what changes can be made and what would be the consequences.

Figure 1. The JetZero Blended Wing Body that USAF partially funds to prototype. Source: USAF and JetZero.

Read more

Bjorn’s Corner: New aircraft technologies. Part 24P. Single or dual aisle fuselage?

Subscription required

August 4, 2023, ©. Leeham News: This is a complementary article to Part 24. Single or dual aisle fuselage? It discusses in detail the drag and weight simulations we have done on different fuselage types for the next generation of “Heart of the Market” airliners.

When it comes to drag and weight for a 250-seat airliner that shall replace today’s Single Aisle, is a Single Aisle fuselage lower in drag and weight than a Dual Aisle fuselage?

Read more

The reality behind the eVTOL industry’s hyperbole, Part 3.

Subscription required

By Bjorn Fehrm

July 27, 2023, © Leeham News: We look at the promises that the VTOL industry has made in their Investor prospects and what the reality is as they come closer to Certification and present their production-level prototypes. We also analyze whether these capabilities will be the final level.

Today we go through the trickiest part of any electric aircraft or eVTOL, the batteries. They are large, very heavy, and the most difficult part to certify on the aircraft, as the battery is dangerous if not designed, produced, and managed correctly.

Figure 1. The Joby Aviation S4 production prototype. Source: Joby Aviation.

Summary:
  • The battery system of an eVTOL sets restrictions on the operational usefulness of the category.
  • The everyday operational utility of VTOLs is far from the industries’ claims.

Read more

Bjorn’s Corner: New aircraft technologies. Part 21. Changed flight profiles

By Bjorn Fehrm

July 14, 2023, ©. Leeham News: Developments in engines and airframe technologies require that the aircraft are flown differently to maximize the benefits.

We start by locking what changes in parasitic and induced drag mean for how airliners fly.

Figure 1. A Truss Braced Wing airliner shall fly higher. Source: Boeing.

Read more

The reality behind the eVTOL industry’s hyperbole


Subscription required

By Bjorn Fehrm

July 13, 2023, © Leeham News: We have done a deep dive series on the cost problems experienced by small airliners and how these make life difficult for alternative propulsion projects.

The eVTOL industry also faces problems, but here it’s more its own overinflated promises that rub. It’s the subject of our next deep dive.

We look at what the top OEMs promised in the past and what the reality is as they come closer to Certification.

When it comes down to it, what missions can be flown and what cannot? Are the missions that can be flown enabling a new industry?

Figure 1. The Joby production prototype as presented on 28th June. Source: Joby Aviation.

Summary:

  • Investor prospects promised Total Available Markets (TAMs) as large as $500billion with flights at up to 200 miles per hour to destinations hundreds of miles away
  • The reality is more profane. None of these promises hold water.

Read more

Bjorn’s Corner: New aircraft technologies. Part 20. Efficient flying

By Bjorn Fehrm

July 7, 2023, ©. Leeham News: We explore different technologies in the series that can make our next-generation airliners more efficient and, thus, less polluting.

We have discussed developments of engine and airframe technologies, such as Turbofans versus Open Rotors and different airframe configurations to minimize drag and, thus, energy consumption.

When utilizing these developments to increase efficiency we must fly the aircraft in a different way depending on the technology.

And how we fly the aircraft is not only influenced by the factors we have discussed. We must consider factors at the airplane level, at the airliner operational level, and finally, at the airline fleet level.

Figure 1. The NMA concepts included dual aisle airliners. Source: Leeham Co.

Read more