Leeham News and Analysis
There's more to real news than a news release.
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.
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.
The range of the Airbus A321XLR, Part 2
Subscription required
By Bjorn Fehrm
September 7, 2023, © Leeham News: The advertised range of 4,700nm for the Airbus A321XLR enables true trans-Atlantic single-aisle routes that can originate further inland, both in the US and Europe. When EASA and FAA demanded that Airbus add extra fire protection around the tank that gives the extended range, rumors told of a substantial range loss.
Last week we could see that whatever the weight increase, the range loss is not substantial. Now we look at what Airbus could do to restore the range of the A321XLR.
Figure 1. The Airbus A321XLR. Source: Airbus.
Summary:
- We could see last week that the range shortfall from the rumored weight increases is less than rumored.
- When we look at the fixes for any range shortfall, they seem straightforward and doable.
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.
Bjorn’s Corner: New aircraft technologies. Part 26. Preliminary design
By Bjorn Fehrm
August 25, 2023, ©. Leeham News: We described the different phases of an airliner development program last week.
We will look at the Preliminary design phase this week, what work is done, the tools used, and how it can be made more efficient.
Figure 1. A typical new airliner family development plan. Source: Leeham Co..
The reality behind the eVTOL industry’s hyperbole, Part 7.
Subscription required
By Bjorn Fehrm
August 24, 2023, © Leeham News: We have looked at the promises the VTOL industry made in their Investor prospects and what the reality is as the VTOLs come closer to Certification and production.
We started by using Joby and Archer as examples; now, we wrap the series by looking at some other top VTOL OEMs and how their claims have changed as the projects come closer to reality.
Figure 1. The Lilium jet VTOL. Source: Lilium.
Summary:
- Joby Aviation and Archer are not alone in backpedaling on promised performance as certification nears; other OEMs that are investor-financed have the same problem.
- In summary, the VTOLs in the first generation can only fly short-range missions. Longer flights run into energy reserve and cost problems.
The reality behind the eVTOL industry’s hyperbole, Part 6.
Subscription required
By Bjorn Fehrm
August 17, 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 production.
We used our Aircraft Performance and Cost model to understand the data for the typical missions for the Joby S4 and Archer Midnight VTOLs and how the economics pans out for these missions. We now look at the results and compare them to what’s been projected from the OEMs.
Figure 1. The Joby S4 VTOL. Source: Leeham Co.
Summary:
- We found the VTOL OEM’s economics for the typical 10-minute shuttle flights optimistic.
- When we go back and look at investor deck projections, the cost comparison to helicopter costs were totally off the mark. When we correct this the VTOL is more expensive to operate then an equivalent helicopter.
Bjorn’s Corner: New aircraft technologies. Part 25. Efficient development
August 11, 2023, ©. Leeham News: We have described a number of technological advances that can be used to make the next-generation airliners more efficient and, thus, more environmentally friendly.
Part of developing more efficient next-generation aircraft is to change the development process to be more efficient. The last Boeing aircraft, the 787, took 7.5 years from launch to entry into service, and Airbus A350 took 8.5 years.
The target is to reduce this by up to 50%, but how?
Figure 1. The Airbus A350 development schedule. Source: Airbus.
Bjorn’s Corner: New aircraft technologies. Part 24. Single or dual aisle fuselage?
By Bjorn Fehrm.
August 4, 2023, ©. Leeham News: This is a summary article to Part 24P. Single or dual aisle fuselage. It summarizes the drag and weight simulations we have done on fuselages for the next generation 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?
Figure 1. The drag components of a Single Aisle airliner at 35kft and M0.78. Source; Leeham Co.