Boeing 737 MAX Production To Be Investigated Amid Debris Findings

Boeing faces scrutiny on two fronts concerning its 737 MAX aircraft. A federal grand jury investigation is underway into the design of the 737 MAX’s flight-control systems. Additionally, The Wall Street Journal, with sources familiar with the details, reported today that factory rules and regulations are being investigated by the US Department of Justice (DOJ) and Federal Aviation Administration (FAA).

737 MAX getty
Boeing is storing approximately 400 737 MAX jets that are awaiting delivery. Photo: Getty Images

Fined for debris left in aircraft

In addition to this, other investigators are looking into Boeing’s compliance with “mandatory production rules and safeguards”. This comes as foreign object debris (FOD) was discovered in various locations of inspected 737 MAXs. Discovered in approximately half of inspected aircraft, FOD was found left in fuel tanks and/or other interior spaces. The material was left behind by workers in the production and assembly process.

Reported FOD includes “tools, rags and other materials,” which would clearly present safety concerns in the daily operation of the aircraft. Boot coverings were also specifically mentioned.

Sources report that the Federal Aviation Administration will possibly pursue civil-enforcement action. This may include a multimillion-dollar fine against Boeing. The federal regulator will also draft plans for increased government oversight and enhanced assembly-line inspections. This is being done in anticipation of MAX production resuming in the months ahead.

Boeing 737 MAX Production To Be Investigated Amid Debris Findings
Foreign object debris was found inside MAX fuel tanks. Photo: Getty Images

While the anonymous source reports that no final regulatory decisions have been made by the FAA, Boeing stated today that it has incorporated additional training for workers and updated its debris-prevention audits.

The Seattle Times had reported in the past that investigators from the Department of Justice were gathering information regarding manufacturing problems at the South Carolina plant where Boeing assembles its 787 Dreamliner model. This issue is also something Simple Flying reported on last July.

“A pattern of assembly-line problems”

Investigations by both the DOJ and FAA include interviews with a Mr. Ed Pierson, who was once a production supervisor in Renton. Pierson alleges a pattern of assembly-line problems that go as far back as 2018. These include fatigued workers, sloppy workmanship, and chaotic assembly-line practices.

Boeing 737 MAX
The 737 MAX grounding has led to airlines being unable to carry out planned refurbishments. Photo: Getty

While Pierson’s allegations did not specifically mention debris, he later stated that the presence of FOD inside an aircraft “is just the sort of mistake that overworked factory employees are likely to make.” Pierson urged senior Boeing officials to temporarily shut down MAX production to deal with the safety issues he flagged.

Government officials conducting the investigation are also inquiring as to why FAA officials took six months to have a face-to-face interview with Pierson after a letter was sent to the Administration’s head warning of an “unstable production environment”.

More recently, an interim report released last month by House Democrats supported Pierson’s claims of undue management pressure to ramp up production rates. The report says that there was intense financial pressure on managers as well as on workers to avoid program delays.

Statement from Boeing

While Boeing says it does not comment on any potential investigations, it provided Simple Flying with a statement on its FOD policy. Here is a portion of it:

“Safely returning the 737 MAX to service is our top priority. While conducting maintenance we discovered Foreign Object Debris in undelivered 737 MAX airplanes currently in storage. That finding led to a robust internal investigation and immediate corrective actions in our production system, which we have also implemented across all of our commercial airplane programs. We are also inspecting all stored 737 MAX airplanes at Boeing to ensure there is no FOD.”

As a precautionary measure, Boeing recommends to its 737 MAX customers to inspect fuel tanks for FOD as part of their storage procedures, this includes checking for corrosion.


The details of the investigation shouldn’t come as too much of a surprise given what we know about the 737 MAX and its origins. With the threat of losing large narrowbody orders to Airbus and its A320neo, Boeing was under huge pressure to deliver a next-generation 737 with similar efficiencies in a very short timeframe.

Given everything both the United States and Boeing are facing now, it will be interesting to see how this resolves and if large penalties will result, and how soon that might be.

What do you think of Pierson’s allegations? What kind of penalties should Boeing face if wrongdoing is confirmed? Let us know your thoughts in the comments.