An inquiry is under way after two British Airways planes "clipped" one another on the ground at Heathrow.
The Boeing reversed into the Airbus A321
BA said a Washington DC-bound Boeing 777 backed into an Airbus A321, which had arrived from Zurich, on 27 July.
BA said both jets were moving slowly at Terminal 4 and all 300 passengers aboard the evening flights would have had their seatbelts on.
"The aircraft will be thoroughly examined before either are permitted to operate again," said a BA spokesman.
There were 200 passengers on board the Airbus and 100 on the Boeing, said BA. No-one was hurt.
They were disembarked and rebooked onto the next available flights. Some passengers were offered hotel accommodation for the night.
BA said: "We are aware that two British Airways aircraft clipped one another as one pulled on to its stand on arrival at Heathrow and the other left its stand.
"We are launching an immediate investigation into what happened.
"Safety and security is paramount to British Airways and we would never compromise that."