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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.
The development program
Before we discuss how to make the traditional airliner development program in a shorter time, let’s look at what phases there are and what will be done in each phase. We also include the rough number of people involved at the aircraft OEM and their suppliers in each phase in Figure 1.
Feasibility phase
Before the actual development of a new airliner starts, there is a continuous ongoing phase at established airliner OEMs called the Feasibility phase. An OEM conducts continuous studies in its current and potential future market segments. These studies are conducted by the OEM’s Future Airplanes group.
The feasibility phase examines interesting market trends and segment sizes, matching them with new technologies and configurations to identify market opportunities. As the studies show an opportunity for a new airliner project, a feasibility project gathers pace and will eventually pass over to a Conceptual design phase.
Conceptual design
The Conceptual design phase can be from a year to several years in length. Typically, it transforms the continuous research in the Feasibility phase to a more focused analysis of a few design candidates and how well these respond to the market segment needs that the airliner project shall satisfy.
The OEM’s Future Airplanes group is now complemented by Line R&D personnel and representatives from Sales and Marketing. The dialogue with key technology providers, especially for the engines, intensifies.
Preliminary design
After the Conceptual design, we proceed to the Preliminary design. Now key suppliers are chosen, and the performance and cost data for the airliner are developed so that performance guarantees and prices can be established. These are presented to the reference airline group and to potential launch customers.
Once the information is solid enough and the customer is ready to order the aircraft, an authority to offer and program launch is initiated. In the preliminary design phase, the team has expanded to hundreds of specialists in different disciplines.
Detailed design
After launch, the preliminary data undergoes various refinement steps, culminating in a design freeze. The freeze now allows for the large work of detailed design to begin. A modern airliner is made of about four million parts. Some of these are standard parts, such as rivets/fasteners, cables/tubes, and connectors, but most are custom designs.
Now, thousands of designers start the job of designing all structural parts in CAD, make stress and other simulations, and then enter all the design data for parts and systems in the PLM (Product Lifecycle Management) system. Subsuppliers start their design work to adapt existing system components or design new ones.
Prototype manyfacturing
Once the detailed design has converged to a release for the production stage, the parts for the aircraft prototypes are ordered based on the produced design data.
The assembly of the prototypes engages hundreds of people from mixed engineering and factory teams.
Testing and Certification
The testing of system components isolated and in rigs is going on as soon as their design are established. The certification work is continuous, spanning from conceptual design to various stages. Here, the timeline focuses on the testing and certification activities performed around the prototype aircraft, as well as their systems in the system rigs.
Production preparation, Production
As detailed design produces the initial designs on parts, they are analyzed for serial production suitability by production preparation engineers.
Final design data is issued to the supply chain, and the production parts are ordered when the testing of systems and prototypes has shown the designs to be ready for production.
Gradually, the serial production of the aircraft starts. The total throughflow times for serial production parts are in excess of two years.
Entry into service, Fleets support
Finally, the training and service departments prepare the hundreds of manuals and databases that must be onboarded with the aircraft at Entry Into Service, EIS.
We will go through these phases, examining the work done, the tools used, and the certification work and interaction that need to be completed. Then we will discuss the possibilities for accelerating the different phases and what’s needed for such acceleration.
Very interesting stuff to follow in this series- thank you, Björn.
Historically, airplane development took 4 years – less for derivatives, and a few months longer for new models. This was the case for 727, 737, 747, 757 and 767 (concurrently) and the 777, and many of the competing products from McDonnell Douglas. It was my clear impression that project management and awesome communication and coordination were at the heart of that record.
In 2002, I had a very clarifying conversation with a very smart, well-informed, hard-working financial analyst. He asked, “Do you really need 40 people in a coordination meeting?” I thought a minute and said, yeah, that sounds about right. He said, “I really don’t know, but GE has [several hundred] propulsion engineers, and Boeing has [about 2/3 as many] propulsion engineers, and maybe Boeing doesn’t need that many.” He said that, in his world the next word after “coordination” was “cost,” and those coordination costs are not really needed with “mature” products like airplanes. [Another long story there, of course.]
Then he said, “that’s what markets do well – manage coordination costs.” In that moment, I was as baffled by his world view, as he was of mine. I said, look; let’s build a new airplane with your market-based view for mature products. If you’re right, you [and people who look like you] will be very happy. If I’m right, we will all be very unhappy.
Two years later, Boeing launched the 787, under the ShareValue business model.
Now, 21 years later, I have to think that question is settled.
The point of this long story, is really a restatement of Scott Hamilton’s review today, of Ortberg’s first year. After one year, we are still not sure whether Ortberg is committed to an engineering problem-solving culture, or is Ortberg still embedded in the Shareholder Value cost-cutting world view?
Bjorn characterizes the Detailed Design phase as frozen. It isn’t, really. In the detailed design phase, the program will need to solve 20,000 problems [Mike Delaney’s number; my number was 40,000, but I defer to Delaney on this point.] Solving those problems early, with design changes that engage all stakeholders is the key to success.
The 4-year cycle times were dependent on the problem-solving culture and the degree of coordination and communication.
The wildly out-of-control cycle times we’ve seen since the late 90’s are the direct consequence of the weak problem-solving culture that you get when pretend your products are “mature” and you let markets try to solve all your problems.
The last problem solving method airplane developed at Boeing was the X-32. Two airplanes from scratch. The first flew in 3.5 years and the second (an airplane that hovers) completed flight test at 4.5 years. It was all completed under the live fire drill that was the merger. The engineering team put their heads down and focused on the job at hand. It couldn’t had have gone better from a development standpoint. Competition was winner take all so not exactly the commercial business model but those airplanes were built to a standard of safety that would have amazed the FAA if they were involved.
Stan:
Great perspective. I have no answers but framing the question is a start.
Even the best run, aka A380 had a couple of show stopper issues. Worst was the wiring. Ungh. Other was the tech issue of the wing ribs shimming, how do you foresee or catch that?
The A350 has gone well, but the lead into it was time consuming in the false starts on the A330 Mk 1-IV. And in the end Airbus did the A330Mk ? and while not a runway seller, its rate 4 (slowly moving up to 5 in a few years).
While not direct, Boeing and NG seem to have produced a prototype F-47 in a short time frame. LM did with the F-35 but then turning it into a viable product, still on going.
Are the testing methods and paperwork confirmation really outdated and a major part of the time delays?
Chuckling at Stan’s comment about the out of control cycle times since the late ‘90’s… and that’s for mostly derivative airplanes, but the real reason is the lack of leadership. Back in the ‘70’s, 80’s, 90’s there were great leaders such as Alan Mulally and Joe Sutter.
One way manufacturers, especially Boeing, speed up the development process is by the use of ‘Exemptions to the Rule’
Meaning the CFR’s have very specific requirements and rules for airplane certification… for everything!
Sometimes meeting these rules requires much more detailed engineering, manufacturing and certification timelines to accomplish to the letter of the law. To skirt this and do it a different way, Boeing (and Airbus) will apply for these Exemptions – perfectly legal – both by the FAA and EASA to work around the law.
The manufacturer however must apply for and meet requirements on approval for an ALOS or Acceptable Level Of Safety – from the regulators for the specific CFR they are trying to skirt. Meaning we will grant this but first prove it’s still safe.
A good example of this is the current Max engine A/I work around until the problem can be solved.
I’m paraphrasing all this because this can all get very detailed.
One only needs to search the FAA website and see the massive amount of Exemptions granted especially to Boeing since the dawn of the jet age. It’s eye opening.
Good job on this series Bjorn!