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“Although the investigation is in its early stages, this incident raises serious questions about Boeing’s manufacturing quality control, oversight of contractors, and communications with the airlines, which may have contributed to the door plug bursting from the side of the airplane.”

WASHINGTON, D.C. – Senators JD Vance (R-OH), Edward J. Markey (D-MA), and Peter Welch (D-VT), members of the Senate Commerce, Science, and Transportation Committee, sent a letter to Boeing CEO David Calhoun requesting answers on the company’s manufacturing quality control, oversight of contractors, and communications. Last week, the door plug of a Boeing 737 MAX 9 operated by Alaska Airlines blew off the side of an airplane flying at 16,000 feet with 177 passengers and crew onboard. Within a day, the Federal Aviation Administration grounded all 737 MAX 9 planes. Subsequently, Alaska Airlines and United Airlines inspection crews found loose door plug bolts on a number of MAX 9 aircraft in their fleets. 

In their letter, Senators Vance, Markey, and Welch urged Boeing to cooperate fully with the National Transportation Safety Board’s (NTSB) ongoing investigation into the incident and called for the MAX 9 fleet to remain grounded until they are fully safe to return to the skies.

The senators’ letter to Mr. Calhoun reads, in part:  

“Although we are grateful that nobody was seriously harmed, this incident still posed an extreme danger for everyone onboard. Had the door plug blown out of the plane at 33,000 feet — and not 16,000 feet — the outcome likely would have been much worse… 

“Boeing’s quality assurance process appears to have been unable to identify the loose bolts — a serious oversight. Even more concerning, Boeing contracts the manufacture and installation of door plugs to Spirit AeroSystems, raising questions about not only Boeing’s internal quality control, but also its oversight of its contractors.”

Senators Vance, Markey, and Welch requested answers to the following questions about Boeing’s quality control procedures by January 18th:

  1. What steps is Boeing taking to provide swift and comprehensive guidance to air carriers conducting safety inspections of 737 Max 9 aircraft?
  2. Why did Boeing pull back its initial Multi Operator Message to air carriers?
  3. What steps is Boeing taking to identify any safety concerns in its supply chain and manufacturing processes that may have contributed to loose bolts?
  4. Is Boeing assessing its oversight of the role a contractor, Spirit AeroSystems, plays in constructing and installing door plugs?
  5. Was Boeing Board of Director’s Aerospace Safety Committee aware of any problems with Spirit AeroSystems’ production quality? If so, what actions has it taken to resolve those issues?

Read the full letter here