The deaths were the single biggest UK loss of life in Iraq
The deaths of 10 UK personnel in Iraq in 2005 could have been avoided if a safety device had been fitted to their Hercules plane, the BBC has learned.
RAF pilots requested that explosive- suppressant foam devices be fitted to fuel tanks two years before the attack in which the men died, RAF papers show.
The Ministry of Defence said none of its planes in Iraq or Afghanistan had foam, but some would be fitted soon.
The foam has been in use in US Hercules aircraft since the Vietnam war.
The attack happened on 30 January, 2005, when a Hercules travelling from Baghdad to Balad was hit by ground-to-air fire which caused an explosion in the right hand wing fuel tank.
A board of inquiry which published its findings in December said the crash was not survivable but did admit that the lack of a fuel tank safety system was one of the factors which could have contributed to the crash.
The crash was the single largest loss of British life in Iraq since military action began in 2003.
The explosive-suppressant foam stops fuel tanks from exploding when pierced by bullets. One US plane shot 19 times in Iraq still managed to land safely.
With the continued lack of foam on Hercules planes, campaigners say they will sue ministers for corporate manslaughter if any more lives are lost because of a lack of protective equipment.
An internal RAF document obtained by BBC Radio 4's Today programme suggested requests were made for the explosive-suppressant foam at least as early as 2002.
The document read: "Urgent operational requests for all Hercules aircraft should continue to be actively pursued. Specifically, all aircraft should be fitted with fire suppressants in fuel tanks."
The programme was told one US pilot refused to fly in a British plane because of concerns he had about safety.
Former RAF Hercules pilot Nigel Gilbert, who trained with the pilot killed in the attack, said: "I believe the probability is that the crew would have survived the attack if the aircraft had explosive suppressant foam in the fuel tanks.
"The crew was so good they could have even put it down in a road or put their landing gear up and landed it straight ahead in the desert. It was as flat as a pancake."
A statement from the MoD said the planes facing the highest risk of attack would be fitted with the foam.
Prime Minister Tony Blair's official spokesman said: "The board of inquiry into the very sad loss of the Hercules did make a number of recommendations and the MoD are implementing those recommendations."
Michael Moore, foreign affairs spokesman for the Liberal Democrats, said it was "scandalous" that only some of the planes were to be fitted with the foam, as dangerous deployments in Afghanistan and Iraq went on.
Shadow defence secretary Liam Fox said the cost would only be about £275,000 plus £50,000 per aircraft.
"If the American and Australian governments are fully protecting their servicemen and women, it's a disgrace we can't," he said.