Part of the landing gear failed to extend properly, but the pilot brought the aircraft down safely, with 114 passengers and crew on board. Up to six people suffered minor injuries - including two crew members - as they slid down emergency chutes in a standard evacuation procedure.
Witnesses described how the four-engined European-made jet slewed down the Heathrow runway, sending off sparks at the end of its flight from Los Angeles.
In a statement, Virgin Atlantic said the Airbus made a successful emergency landing at 4.20pm using three, instead of four, sets of landing gear. The airline added: "The flight had proceeded normally until the crew routinely extended the landing gear on approach to Heathrow. The crew received indications that the left main landing gear did not fully extend and so conducted a fly-past to enable a visual inspection of the gear to be undertaken from the ground, which confirmed that the left-hand gear was not fully extended.
"Indications in the cockpit confirmed that all three remaining landing gears had extended normally. The aircraft completed a normal approach and the crew accomplished a textbook emergency landing and came to rest on the runway."
Witness Rob Seabrook said there appeared to be problems with the undercarriage of the airplane as it came down to land, with one wheel-bay not having opened.
Another witness, John Asher, said "He held it off the ground as long as he could, I guess to reduce speed to the minimum, and as it did eventually touch down it was obviously quite one-sided.
"As it went down the runway sparks were flying and it slewed off the end of the runway, virtually out of sight and there was a lot of smoke around," he said.
As the aircraft circled the airport, onlookers realised something was wrong.
Estate agent Giles Newby told BBC1's Six O'Clock News: "It was in a position in the sky which it shouldn't have been, well below the cloud base. It was banking very severely. We were concerned that if it was going to come down, it was going to come down in a populated area."
Four passengers were taken to Ashford Hospital and treated for minor injuries, the London Ambulance Service said.
One of the two runways at Heathrow was closed and passengers on other flights were delayed.
Virgin Atlantic said: "There will be internal investigation as well as the Air Accident Investigation Board inquiry. At the moment, it is too early to say what caused the incident."
The airport chaplain, Reverend Brian Lacock, who was comforting passengers, said: "Everybody was very relieved. They were singing the praises of the captain for bringing her in.
"All the passengers were saying the pilot did a wonderful job and so did the crew. Everybody was praising them."Reuse content