Two planes clipped each other at Heathrow Airport, causing minor damage to both aircraft.
There were no injuries and no delays in the incident, which involved a British Airways plane with 121 passengers on board and a Virgin Atlantic aircraft.
Virgin Atlantic said its empty Boeing 787-9 was being towed from the stand at Terminal 3 when it happened.
The airline added that the plane had just landed and was being transported to a different part of the airfield.
One of the wings of the plane being towed clipped the other aircraft.
The passengers on the British Airways flight were scheduled to depart to Accra, Ghana, at 12:40 BST.
British Airways said it provided an alternative aircraft for them, which was rescheduled to take off at 18:00.
Virgin Atlantic said it was investigating and that maintenance checks were being made on its aircraft, which has been taken out of service.
The tow movement was provided by a ground-handling company under contract by Virgin Atlantic, it said.
A Heathrow spokesperson said: "We are working alongside emergency services and our airline partners in response to an incident involving two aircraft on the ground earlier today."
The spokesperson added: "At present, no passenger injuries have been reported and we do not anticipate there to be any ongoing impact to airport operations."
Emergency services attended the scene as a precautionary measure.
The Met Police said it was supporting the airport authorities and the Air Accidents Investigation Branch with an investigation into the circumstances.