Plane's door comes off and lands 20ft from couple out for a walk

Parts of the 70lb door from the British Airways flight badly damaged two cabin windows. Damage was also caused to the plane’s fuselage and tail fin, and fragments of the 6ft by 4ft underwing access door were even forced inside the cabin.

Some of the 272 passengers on board the Antigua-bound flight were so terrified they started praying.

One said: "There was the sound of a massive crack as the panel hit the windows. It was horrifying. No-one knew the extent of the damage. People were scared stiff."

A couple walking in woods near Reigate, Surrey, saw a "substantial" part of the door hit the ground just 20ft from them and another "large portion" fell nearby. Other debris was discovered by a dog walker.

A report into the incident said that the captain of the plane decided to return to Gatwick but, while he was dumping fuel prior to landing, a "gradually increasing hissing noise" was heard around the damaged windows and a slight vibration felt through the cabin floor.

The captain thought this could indicate a "deteriorating situation" and immediately returned to the airport, where the plane touched down safely 45 minutes after taking off. However, it was some ten tonnes above its normal maximum landing weight.

The report, by the Department for Transport’s Air Accident Investigation Branch (AAIB), concluded: "Although major airframe damage did not occur in this case, the loss of the door constituted not only a hazard to those on the ground but it also had the potential to hazard the aircraft."

Investigators said that cabin crew members had felt "a thump and heard a loud bang" when the door detached in the June 2003 incident.

The outer pane of a window was found to have suffered substantial impact damage, while debris found inside the cabin included a dark blue 2sq in fragment.

According to the AAIB report, this section was thought to have been forced into the cabin between a window seal and a window frame.

Later inspection of the aircraft found six deep gouges in its fuselage, caused as the door was thrown open violently as the Boeing 777 was climbing towards 6,000ft.

The report said it was likely that only one of the door’s 13 catches had been fastened, despite several pre-flight inspections by a variety of different people.

It said the failure to spot this error could have been caused by a deviation from standard checking procedures, which "may have been commonplace". The AAIB recommended a review of BA’s maintenance procedures.

BA said it had immediately carried out its own investigation following the incident and had since made several changes to its maintenance systems and procedures.

A spokesman said yesterday: "We note the one recommendation in the AAIB report, which we co-operated with. We have an open safety culture and always study these rare events carefully, to ensure we learn from them."