June 29, 2022

Why did Boeing halt production of the 737 for 10 days in May?

Supply issues have hit Boeing and others before, but haven’t completely halted production of the 737 or other planes. So what has changed?

Boeing has had production issues before, most recently with the 787. While these were technically delivery issues, not production issues, they were certainly related to defects of some sort. Boeing is currently in talks with the FAA to finalize terms for inspecting its 787 backlog.

Photo: United

Boeing halted production of the 737 MAX when the type was grounded. But the plane was returned to service more than a year and a half ago now. Boeing is busy working on certifying the remaining variants of the family. But this production stop affected the current variants of the aircraft. According to several sources, the problem is related to a wiring connector.

All certified aircraft components come with the appropriate certifications and approvals. Boeing therefore cannot simply replace a “low” wiring connector with a different part to continue production of the 737. The pandemic has caused many supply chain disruptions around the world, including some for seemingly “simple” components or raw materials. Sudden, mostly unpredictable lockdowns and/or additional checks have had this effect, among others.

[Not] Keep things in stock

One aspect of mass production that likely has a role in Boeing’s 737 shows in May is “just-in-time” manufacturing. Simply put, it is a process that allows a manufacturer to avoid having to keep large inventories of a part in stock. The principle applies to complex machines such as cars or planes. With thousands or even millions of parts, the storage space and the sorting facilities that large stocks would require, pose limits to production.

As the name suggests, just-in-time manufacturing brings the necessary parts into the factory just as they are fitted to the product. But as Leeham News explainsthis requires a fairly advanced level of coordination and timing, with suppliers and contractors having their own subcontractors, with their own supply chains. And during the pandemic, this long-established choreography has faltered — or failed.

To maintain its 737 production, Boeing had to [re]introduce some stocks of key parts. Other top tier manufacturers and suppliers have done the same. But that’s far from the whole story. The pandemic and its aftermath may have been (and still are in some places) a challenge. But this is not the first time that Boeing has had delivery delays for key components.

Photo: Air Canada

737 Production and “traveled” work

Airbus has also faced similar issues in the past. And when they did, manufacturers didn’t have to shut down their 737, A320 or other production lines for 10 days or more. What they did was keep the production line moving and worry about missing parts later. Obviously, this does not work for ALL parts. But it is often possible to continue the rest of the assembly, without stopping production.

This is called “shifting labor” and can be a necessary evil of just-in-time manufacturing. But this is something manufacturers try to avoid as much as possible. It is often necessary to disassemble several components to reach the location of the missing parts. This makes this work laborious and inefficient. It can also introduce failure points and quality issues.

Why did Boeing halt production of the 737 for 10 days in May?

Photo: Boeing

So in May, Boeing decided to shut down its 737 production line in Renton, keeping the planes in the line, rather than taking them outside and “travelling the work”. Boeing still lags considerably behind Airbus. The American manufacturer is aiming for a production rate of 31 737 MAX per month by the end of the year. Despite these latter issues, that would remain the goal. Airbus is currently in the mid-40s per month, aiming for over 50 by the end of the year.

As we have seen, Airbus has had its own production problems. The European manufacturer had to update or replace some of its older Finish Assembly Lines (FAL) for the A320 Family. Airbus has done much of this work during the pandemic, in space where it previously built the A380, in Toulouse, France. Airbus also wants to introduce another A320 production line at its US plant in Mobile, Alabama.