A grass fire broke out next to Heathrow's southern runway, 27L, on Friday 5 September, forcing air traffic control to close it and switch to single-runway operations before both runways reopened later that morning, Heathrow confirmed.
Two long-haul arrivals were diverted as a result. A flight from San Francisco was sent to Manchester and a flight from San Diego landed in Birmingham instead of Heathrow, according to the Daily Mail, which published video showing smoke drifting across the southern runway near a parked Qantas jet.
Heathrow's runway operations account described the incident on social media as a grass area fire adjacent to runway 27L that had closed it, putting the airport into single-runway operations on 27R until the blaze was cleared, a report on the incident said.
Heathrow said in an official statement: "Earlier today our teams acted quickly to safely resolve a grass fire adjacent to the southern runway. Thanks to their swift response, the fire was extinguished quickly and both runways are fully operational. A huge thank you to everyone involved. We apologise for any disruption and thank passengers for their patience and understanding. We wish everyone a safe onward journey."
Passengers on social media described frustration at delays and knock-on disruption to trains serving the airport. Flight tracking during the single-runway period showed a backlog building as controllers worked departures and arrivals through the one open runway, meaning some delays are likely to persist for a few hours after the reopening while schedules catch up.
Friday's fire foll