Loose nut caused oxygen fire.
The report attributed the mishap to a loose nut connecting a metal oxygen tube to a fitting that was poorly tightened by a civilian maintenance contractor, L-3 Communications, during a major overhaul of the 51-year-old aircraft. The flaw had gone undetected in the year since the jet was returned to the 55th Wing in the spring of 2014.
But the report also suggests that problems at L-3 go beyond a single nut.
Investigators found that only one of 11 nuts at junctions on the jet’s oxygen system had been properly tightened during the overhaul at L-3’s Greenville, Texas, maintenance base.
They also found evidence L-3 was using old, substandard parts in the oxygen system, and that some parts were the wrong size. And it criticized the standards L-3 mechanics followed in maintaining the oxygen systems on the 1960s-vintage aircraft as vague and contradictory.
The report attributed the mishap to a loose nut connecting a metal oxygen tube to a fitting that was poorly tightened by a civilian maintenance contractor, L-3 Communications, during a major overhaul of the 51-year-old aircraft. The flaw had gone undetected in the year since the jet was returned to the 55th Wing in the spring of 2014.
But the report also suggests that problems at L-3 go beyond a single nut.
Investigators found that only one of 11 nuts at junctions on the jet’s oxygen system had been properly tightened during the overhaul at L-3’s Greenville, Texas, maintenance base.
They also found evidence L-3 was using old, substandard parts in the oxygen system, and that some parts were the wrong size. And it criticized the standards L-3 mechanics followed in maintaining the oxygen systems on the 1960s-vintage aircraft as vague and contradictory.