The crew of a Cessna Citation I that came down soon after takeoff from Biggin Hill Airport, southeast of London, on Sunday is understood to have reported engine vibration before the accident, which killed all five on board. A pilot flying nearby reported hearing the Citation–S/N 500-0287 and registered VP-BGE–make a “mayday” call before being cleared to return to land. One of two pilots aboard the Citation reported the jet was “going down” before it hit an unoccupied house about three miles from the airport and close to the extended runway centerline. Andrew Walters, chief executive of Biggin Hill owner Regional Airports, confirmed to BBC Radio that the Citation crew had advised its intention to return to the airfield. The NTSB, FAA, Cessna and the Royal Air Force are assisting the UK Department for Transport Air Accidents Investigation Branch. The pilots have been identified as Michael Roberts and Michael Chapman, and two of the passengers were touring car driver David Leslie and team owner Richard Lloyd. The third passenger has not yet been officially identified.