Tony Cable, a former senior investigator at the Air Accident Investigations Branch (AAIB) has been engaged by the legal team representing the family of pilot David Traill.
Mr Traill was one of 10 people killed when the Police Scotland helicopter he was piloting plunged into the Clutha Vaults pub in Glasgow on the night of November 30 last year.
Two police constables on board and seven people on the ground also died. An AAIB investigation is still ongoing.
In three decades at the AAIB, Mr Cable worked on investigations into the Lockerbie bombing and the Paris Concorde crash.
He also headed the initial air accident inquiry into the RAF Chinook crash on Mull of Kintyre in 1994.
The tragedy claimed the lives of all 29 on board, including 25 of the UK's most senior intelligence experts, and sparked a bitter 17-year legal battle by the pilots' widows to overturn the 1995 verdict of "gross negligence" by an RAF board of inquiry.
It subsequently emerged that the Ministry of Defence had been warned nine months before the crash that the Chinook's onboard software system, Fadec, was "positively dangerous". In 2011, a review of the case found the pilots should never have been blamed.
Mr Cable was critical of the MoD for witholding key information from investigators.
Since leaving the AAIB he has set up his own consultancy, AFTA Ltd, in Guildford, which specialises in "gathering and reviewing available evidence" on air crashes, particularly in relation to engineering failures.
Aviation consultant Chris Yates said Mr Cable was respected as an "extremely shrewd investigator" and "extremely knowledgeable about his subject matters".
He added: "Without a doubt the expertise that he has gathered over very many years is crucial to their side of the investigation. That's probably the primary reason why they've chosen Tony Cable to assist."
An investigation by the AAIB is still ongoing but has raised significant questions over the cause of the tragedy.
The AAIB's most recent update in February stated the aircraft's engines had "flamed out" as a result of fuel starvation, but the key mystery has been why this occurred with 76kg of fuel left in the main tank.
Experts have suggested the situation points to possible human error as vital transfer pumps - controlled manually by switches in the cockpit - were turned off when they should have been on throughout the flight.
As a result, fuel could not transfer from the main tank into the supply tanks which in turn power the engines. As a result it is feared Mr Traill could be blamed.
The aircraft, a Eurocopter EC135, was also fitted with a Fadec system. The system monitors and controls the function of the engines to ensure they operate at "maximum efficiency".
Pilots cannot manually override Fadec if it malfunctions. If Fadec fails, the engines fail. However, investigators have found nothing to indicate a software glitch on the Clutha helicopter.
Under the strict liability laws governing aviation, Bond - which operates helicopters for the police and ambulance service - is automatically liable for compensation, regardless of the outcome of the AAIB probe or a likely Fatal Accident Inquiry (FAI) in future.
The decision by the Traill family's lawyers to recruit Mr Cable could suggest that they are anticipating an FAI and the likelihood of having to argue against human error in favour of mechanical failure.
But Mr Yates said it would be wrong to second-guess the AAIB's probe.
He said: "I don't think it [hiring Mr Cable] gives us any clues as to the direction of the AAIB investigation at all.
"I think it probably serves the purpose of having all the ducks in a row, so to speak - making sure that any aspect is covered."
Mr Cable said he was unable to comment.