The Australian Transport Safety Bureau did not conduct an on scene investigation of this occurrence. The information presented below was obtained from information supplied to the Bureau.
The crew of a Boeing 737, registered VH-TAH, reported that, on 15 May 2004, during the take-off roll on runway 34 Left at Sydney Kingsford Smith Airport, they felt shuddering from the nose wheel. The crew of a subsequent landing aircraft reported debris on the runway. An inspection found tyre segments and pieces of aircraft structure. The 737 crew were notified and elected to return for a landing.
An investigation by the operator found that the 737 struck a Boeing 747 thrust reverser blocker door that had fallen from an aircraft that had previously used the runway. That door damaged the 737 nose landing gear tyre and gashed the aluminium skin of the fuselage. The investigation was unable to identify the 747 and whether the loss of the door occurred during take-off or landing.
This was the second reported occurrence of a blocker door falling from a 747 aircraft. At least two 747 operators (one Australian and one international) are known to have found that an earlier 747 blocker door modification had a deficient metal/composite bond. The Australian 747 operator has initiated a project to scope and implement a new modification program to repair or replace all blocker doors.