"The insider, an airman with 20 years' experience, revealed a number of technical problems and fuel leaks, including an incident during a UK flight in November 2004 that he believed could have brought down the plane.
It was only when they landed that the damage was discovered
In the incident, he said, a hot-air pipe had ruptured below fuel tanks and superheated air had "blasted out", melting the seals"
I have first hand experience of said incident as I was on shift at the time. As a result of the pipe rupturing, (it was never ascertained during which stage of flight the failure occurred) that particular system was isolated and not reinstated for a good few months until inspections and/or replacement pipes were fitted. It eventually led to that particular ac being withdrawn from service (after sitting in a shed for a good few months whilst the lords and masters decided what to do with it) and sent to be chopped up at Woodford.