Airbus A340 Crash lands at Heathrow Airport 5th November 1997 With partial undercarriage failure.
Airline = Virgin Atlantic
Pilot's Name = Tim Barnby
Investigation discovered that a 4 inch metal pin belonging to the left braking system had worked loose during take-off and had become lodged in such a way as to keep the wheel-doors from opening. Accident Report- http://flightsafety.org/ap/ap_dec00.pdf