Leeham News and Analysis
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Bjorn’s Corner: Faster aircraft development. Part 9. Conceptual phase Certification work.
By Bjorn Fehrm and Henry Tam
September 26, 2025, ©. Leeham News: We do a series about ideas on how the long development times for large airliners can be shortened. New project talks about cutting development time and reaching certification and production faster than previous projects..
The series will discuss the typical development cycles for an FAA Part 25 aircraft, called a transport category aircraft, and what different ideas there are to reduce the development times.
We will use the Gantt plan in Figure 1 as a base for our discussions.
Figure 1. A generic new Part 25 airliner development plan. Source: Leeham Co. Click to see better.
*** Special thanks to Andrew Telesca for helping with this article***
Bjorn’s Corner: Faster aircraft development. Part 8. Conceptual System design.
September 19, 2025, ©. Leeham News: We do a series about ideas on how the long development times for large airliners can be shortened. New project talks about cutting development time and reaching certification and production faster than previous projects..
The series will discuss the typical development cycles for an FAA Part 25 aircraft, called a transport category aircraft, and what different ideas there are to reduce the development times.
We will use the Gantt plan in Figure 1 as a base for our discussions.
Figure 1. A generic new Part 25 airliner development plan. Source: Leeham Co. Click to see better.
*** Special thanks to Ron Everlove for helping with this article***
Bjorn’s Corner: Faster aircraft development. Part 7. Conceptual Design.
By Bjorn Fehrm and Henry Tam
September 12, 2025, ©. Leeham News: We do a series about ideas on how the long development times for large airliners can be shortened. New project talks about cutting development time and reaching certification and production faster than previous projects..
The series will discuss the typical development cycles for an FAA Part 25 aircraft, called a transport category aircraft, and what different ideas there are to reduce the development times.
We will use the Gantt plan in Figure 1 as a base for our discussions.
Figure 1. A generic new Part 25 airliner development plan. Source: Leeham Co. Click to see better.
Bjorn’s Corner: Faster aircraft development. Part 6. IT support.
By Bjorn Fehrm and Henry Tam.
September 5, 2025, ©. Leeham News: We do a series about ideas on how the long development times for large airliners can be shortened. New project talks about cutting development time and reaching certification and production faster than previous projects.
The series will discuss the typical development cycles for an FAA Part 25 aircraft, called a transport category aircraft, and what different ideas there are to reduce the development times.
We will use the Gantt plan in Figure 1 as a base for our discussions.
Figure 1. A generic new Part 25 airliner development plan. Source: Leeham Co. Click to see better.
Bjorn’s Corner: Faster aircraft development. Part 4. Feasibility studies.
By Bjorn Fehrm and Henry Tam
August 22, 2025, ©. Leeham News: We do a series about ideas on how the long development times for large airliners can be shortened. New projects talk about cutting development time and reaching certification and production faster than previous projects.
The series will discuss the typical development cycles for an FAA Part 25 aircraft, called a transport category aircraft, and what different ideas there are to reduce the development times.
We will use the Gantt plan in Figure 1 as a base for our discussions.
Figure 1. A generic new Part 25 airliner development plan. Source: Leeham Co. Click to see better.
Bjorn’s Corner: Faster aircraft development. Part 3.
By Bjorn Fehrm
August 15, 2025, ©. Leeham News: We do a series about recent ideas on how the long development times for large airliners can be shortened. New project talks about cutting development time and reaching certification and production faster than previous projects.
The series will discuss the typical development cycles for an FAA Part 25 aircraft, called a transport category aircraft, and what different ideas there are to reduce the development times.
We will use the Gantt plan in Figure 1 as a base for our discussions. Before we start the discussions, we outline the process to certify a transport category aircraft under the US FAA 14 CFR Part 25 regulations and how it relates to the Figure 1 plan.
Figure 1. A generic new Part 25 airliner development plan. Source: Leeham Co. Click to see better.
Bjorn’s Corner: Faster aircraft development. Part 2.
By Bjorn Fehrm
August 8, 2025, ©. Leeham News: We do a series about ideas on how the long development times for large airliners can be shortened. New projects talk about cutting development time and reaching certification and production faster than previous projects.
The series will discuss the typical development cycles for an FAA Part 25 aircraft, called a transport category aircraft, and what different ideas there are to reduce the development times.
We will use the Gantt plan in Figure 1 as a base for our discussions.
Figure 1. A generic Part 25 airliner development plan. Source: Leeham Co. Click to see better.
Bjorn’s Corner: Faster aircraft development. Part 1.
By Bjorn Fehrm
August 1, 2025, ©. Leeham News: Four years ago I did a series about aircraft development together with Henry Tam and Andrew Telesca. Both worked on the Mitsubishi Spacejet program. You can find the series here.
It was about the arduous task of developing and producing a certified aircraft for the FAA Part 23 standard and its EASA equivalent. The idea was to better describe what’s ahead for the many upstarts that wanted to develop 9-seat and 19-seat alternative propulsion aircraft.
Now we do a series about recent ideas on how the long development times for large airliners can be shortened. New projects talk about cutting development calendar time by one-third or more. Is this realistic?
Figure 1. The A350 development schedule from December 2011. Source: Airbus.
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Bjorn’s Corner: Air Transport’s route to 2050. Part 4.
By Bjorn Fehrm
January 10, 2025, ©. Leeham News: We do a Corner series about the state of developments to replace or improve hydrocarbon propulsion concepts for Air Transport. We try to understand why the development has been slow.
We listed the different projects in the second Corner of the series that have come as far as flying a functional model or prototype. In Part 3, we went through some of the causes of the slow growth. It was a mix of inexperienced startup managments, all wanting to be the new Elon Musk but lacking elementary knowledge in the aeronautical field, to what is the real hard part of an alternative propulsion concept.
Many startups developed new electric motors for eAirplane or eVTOL use, a relatively straightforward development when the real hard part is the batteries. We described how batteries differ significantly from fuel as an energy source in Part 3.
Now, we add a market aspect that is poorly understood by most players.
Figure 1. The Pipistrel Velis Electro trainer. Source: Pipistrel.
Bjorn’s Corner: Air Transport’s route to 2050. Part 3
By Bjorn Fehrm
November 1, 2024, ©. Leeham News: We do a Corner series about the state of developments to replace or improve hydrocarbon propulsion concepts for Air Transport. We will find that development has been very slow.
Last week, we listed the different projects that have come as far as flying a functional model or prototype, as we need this filter to reduce the hundreds of projects that have declared they want to develop such an aircraft type. We can see that we have only a certified two-seat trainer, and one project has a prototype that has started certification, the CX300 six-seater in Figure 1.
Why is the progress so slow?
Figure 1. The Alia CX300 six-seater started certification in 2023. Source: Beta Technologies.