Verdicts of accidental death were returned by an inquest jury today after five men were killed when their private jet crashed into a house.
Pilot Michael Roberts, 63, co-pilot Michael Chapman, 57, and passengers David Leslie, 54, Richard Lloyd, 63, and Christopher Allarton, 25, died after the Cessna Citation 500 suffered a mechanical fault.
The crew on board the twin-engined, Bermuda-registered aircraft reported problems about a minute after take-off from Biggin Hill in south London en route to Pau in south west France.
All five on board died when the private jet crashed into an empty house in Romsey Close, Farnborough, south east London, causing a major fire which destroyed the building.
Returning their verdicts at Bromley Civic Centre, the jurors said the presence of "black box" flight recording equipment would have helped with the investigation into the cause of the crash.
Coroner Roy Palmer said he would be writing to the relevant authorities after investigators said their inquiries were hampered by the lack of a "black box" recorder.
The Air Accidents Investigation Branch (AAIB) had also recommended changing the wording on an inflight checklist and making it mandatory to examine rivets during maintenance checks.
Dr Palmer said: "I will be writing a Rule 43 letter to back up the recommendations already made by the AAIB in the hope that some steps can be taken to prevent this problem happening again and, if it does, making analysis of the problems rather more easy."
The jury inquest heard that mechanical failure was caused after a small rivet head which secured the left engine cut-off lever was missing and could have resulted in the inadvertent shutdown of the left engine.
About a minute after air traffic control gave permission for the aircraft to ascend to 2,400ft from Biggin Hill, Mr Roberts asked to make an immediate return because it was felt there was engine vibration.
Mr Roberts, from Effingham, Surrey, then told controllers: "We have a major problem, a major problem. It looks as though we're going in, we're going in."
Witnesses reported seeing the aircraft flying low above the residential area and a playing area before hitting the house just after 2.30pm.
House owner Edwin Harman was away on holiday but his wife Pat had returned from the break before her husband and was heading home at the time of the accident.
The garage of a neighbouring house and a car parked next to it were also destroyed by the impact and ensuing fire, but no one on the ground was injured.
Dr Palmer said it was "extremely fortuitous" that no one was in the house at the time and it was through "great good fortune" that no one was killed on the ground.
The inquest heard that it was "most likely" that a mechanical failure within the air cycle machine - part of the air conditioning and pressurising system - caused what was believed to be engine vibration which led the crew to try to return to Biggin Hill.
Mark Jarvis, senior engineering inspector at the Air Accidents Investigation Branch (AAIB), also said that the missing rivet head could have resulted in the inadvertent shutdown of the left engine, even though as a Category A engine it was capable of operating using one engine.
A bid to relight the second engine was most likely started before the relit first engine reached idle speed.
It meant there was not enough time for thrust to be built up to help halt the jet's rate of descent before it crashed into the house.
The AAIB made recommendations to the US-based Federal Aviation Administration to have rivets included as part of maintenance checks and also to review the wording of a checklist document.
However, the FAA said it believes the current system is adequate and has not acted on the recommendations made by the AAIB, the inquest heard.
There was no evidence of pre-existing defects with the Cessna aircraft and it had undergone an inspection in the January before the crash.
Keith Conradi, chief inspector of the AAIB, said their investigation was made more difficult by the absence of any "black box" recorder on the plane, registration VP-BGE.
The Cessna was not required by law to have had a black box flight recorder but among the recommendations made by the AAIB in the wake of the tragedy was for aircraft of this type to be fitted with them.
Dumfries-born former British Touring Car Championship driver Mr Leslie was a father of two who was Scottish karting champion five times before winning the Formula Ford title in 1978.
Apex Motorsport boss Mr Lloyd, also a former BTCC runner-up, had three daughters and a wife. Mr Chapman was from Shoreham in West Sussex.
Mr Allarton, who lived in Coventry, had graduated from Coventry University with a 2.1 in motorsport engineering and was part way through a Master's degree when he was offered the post at Apex.
Following the hearing, Mr Allarton's father, Richard, said: "There was nothing that surprising and the verdict was uncontroversial.
"It was clearly concerning for us to come down here and find out the type of format we would encounter and the information that would come out.
"Although the verdict was simple, it has taken three years to get here."
He said he would like to know why the FAA rejected the AAIB's recommendations concerning maintenance checks on rivets and changing the wording on a checklist document.
Mr Allarton said: "The AAIB made these recommendations for very good reasons, certainly in relation to the rivet. If you haven't seen these instances in the past, that doesn't mean they won't happen in the future.
"This is the first occurrence of a rivet failure which could lead to further occurrences because these aircraft are now quite old."
He added: "In fairness, I don't think the investigators are saying that this was the cause of the accident. They would say they are unsure of the accident.
"But here is a problem that they are aware of which could be a contributory factor and it could and should be dealt with."
Mr Allarton praised the role of the AAIB and the police whom he thanked for their compassion in their dealings with the families.