Report: Presidential aircraft maintainers ignored cleaning procedures meant to avoid fire

Shoddy maintenance work on an aircraft in the Air Force One fleet at a Boeing facility in Texas last year caused more than $4 million in contamination to the aircraft's oxygen system, the Air Force said in an accident investigation summary released this week.

Air Force Materiel Command chief Gen. Ellen Pawlikowski convened an Accident Investigation Board to review the incident, though the service did not say when that assessment began.

"Three Boeing mechanics supplied and used contaminated tools, parts, components, a regulator, and an unauthorized cleaning procedure while performing oxygen system leak checks" during regular maintenance on the VC-25A from April 1-16, 2016, the May 9 summary stated. "To prevent a fire hazard, the VC-25A aircraft maintenance manual requires all tools and components used on the . . . oxygen systems to be 'oxygen clean' so contaminants do not exceed specified levels prior to oxygen system maintenance."

Mechanics did not heed "explicit warnings" about cleanliness during their work, lacked enough oversight of the timeliness and quality of that work, and did not use what they learned in training to properly maintain the oxygen system, the report stated.

The first Boeing mechanic gave another worker parts that were not properly cleaned and a cleaning solution to use on the aircraft's oxygen system, according to the report. The second mechanic and a third looked for contaminated parts on the aircraft, and the third worker tried to sanitize those parts and a regulator built by the second mechanic with the solution in an "unauthorized procedure."

The second mechanic "connected these parts, components, and the regulator to the MA’s oxygen system," the summary said. "Upon finding a non-oxygen clean regulator connected to the MA, Boeing tested the regulator and contamination was found."

No one was hurt as a result of the improper work.

(UPDATE MAY 10: "Boeing is committed to partnering with the United States Air Force to provide the highest standard of support for the VC-25A," company spokesman Jerry Drelling said May 10. "Because of our commitment to our customer, we self-funded all mitigation and repair work. As noted in the AIB report, Boeing took swift action to self-report the incident to the U.S. Air Force.")

The Air Force is currently in negotiations to replace the Air Force One fleet of two 1990s-era Boeing 747-200s -- designated the VC-25A -- with two 747-8 aircraft, to be delivered in fiscal year 2024. Presidential aircraft are based at Joint Base Andrews, MD.

The service did not answer further questions by press time.