Common Themes
Flawed Assumptions
Within the first few years of service, the Concorde fleet had experienced a relatively high rate of tire failures, and associated airplane damage. The most serious of these incidents occurred on June 14, 1979 during takeoff from Dulles International Airport. In this incident, a dual tire failure occurred, followed by a wheel failure that resulted in significant damage to the left wing, including debris that penetrated several fuel tanks.
Photo of left wing penetration by wheel fragments from June 14, 1979 incident (left)
Photo of fuel leaking from Concorde's left wing on take-off from Dulles International Airport, June 14, 1979 (right)
Photo of a piece (32 x 32 cm) of the No. 5 fuel tank bottom
recovered from runway 26 following takeoff of flt 4590
on July 25, 2000
Of the 57 tire failure/deflation events that the investigators studied, the Dulles incident was the only one where a piece of tire tread was found to have penetrated a fuel tank. In the early 1980's, several safety enhancements were implemented into the Concorde fleet intended to improve tire reliabilities, and reduce the risk of wheel failure. In the nearly 20 years that followed, substantial improvements in the rates of tire failures were observed.
As a result of substantial improvements in tire reliabilities, it was generally assumed that the risks associated with tire failures had been adequately mitigated. A tank failure similar to that of flt 4590 had never been observed in civil aviation, involving a piece of tire debris causing large fuel tank openings, and a massive fuel leak.