A TWA Boeing 747 flying from Los Angeles to London with more than 200 people on board lost part of a wing slat as it prepared to land at Heathrow Airport, the airline said Friday.
The Department of Transport said officers from the Air Accident Investigation Bureau have launched an inquiry into the April 20 incident, which a TWA spokesman called a "minor accident."
Aviation experts said the loss of a slat may affect low-speed handling and might force an aircraft to land at a faster speed.
The leading edge slats are 6 feet long and positioned along the front of each wing to increase lift. They are operated hydraulically to change the air flow over the wing and allow the aircraft to land at a slower speed.
A TWA spokesman, who demanded anonymity, said a 2-foot piece of the slat between the fuselage and the No. 3 engine on the right wing fell off after a bolt broke. This forced up the flap, breaking off a section of it, the spokesman said.
However, he said the damage did not cause any problems with the handling of the aircraft and denied there had been any emergency.
The spokesman said the piece that fell off would have weighed about four pounds. He said authorities were notified but the piece has not been found, he said.