The government is investigating how many military personnel have been diagnosed with cancer, after claims that some helicopters left crew exposed to toxic fumes.
At least six cases have already been settled out of court by the Ministry of Defence (MoD), with dozens of other air crew and families understood to be in the process of suing.
They claim that officials knew about safety concerns with certain aircraft as far back as 1999, but chose not to tell the crew or introduce sufficient safety precautions.
The MoD says it takes “the health of our personnel extremely seriously” and is currently testing the exhaust emissions of some military helicopters.
Diseases contracted by some of the crew who flew the helicopters include lung cancer, throat cancer, testicular cancer and some rare forms of blood cancer.
The Times reported last year that at least three former air crew have died and others have been told their cancer is terminal.
It’s understood the government accepts that the design of some rotary wing aircraft increases the likelihood of engine exhaust fumes entering the cabin.
Benzene, which is a known human carcinogen, is an element present in aircraft fuel.
In November, the government began testing helicopter exhaust fumes, but it’s understood that officials still believe there is no risk to health.
The MoD has confirmed it is now carrying out work to determine the number of armed forces personnel who have served as air crew and been diagnosed with cancer.
It’s understood that this work officially began earlier this year; covers the RAF, the Army and the Navy, and will include veterans as well as active personnel.
When approached by BBC News, the MoD was unable to say when it hopes to come up with an initial estimate of the number of people potentially affected.
But one Westminster source familiar with the work said that complexities around accessing veterans’ health records mean it is likely to take years.
More than 150 people are thought to have approached law firms claiming to have been affected, but many will not be eligible for compensation, as the law allowing claims against the MoD only came into effect in 1987.
At least four types of aircraft have been named in legal documents, including the Sea King, Westland Wessex, Puma and CH-47 Chinook.
The law firm Hugh James, which is representing many of the families affected, claims that risks surrounding the Sea King were made clear to the MoD in 1999.
They said a report “recommended modifications to the aircraft to divert the exhaust fumes” but claimed the MoD “failed to act on these recommendations” and “failed to make servicemen aware of the potential dangers and the risk of cancers developing”.
The Sea King was used in British military operations between 1969 and 2018 and has in the past been flown by both King Charles and the Prince of Wales.
The Westland Wessex was retired in 2003, while the Puma and CH-47 Chinook are still in use.
The MoD pointed to previous helicopter tests carried out on behalf of the RAF that didn’t show any indication air crew were being exposed to dangerous levels of contaminants.
Louisa Donaghy, a senior associate at Hugh James, said the firm was representing more than 40 former military personnel but warned there could be more.
“It’s encouraging that the MoD has begun work to understand the scale of this issue, but the process must be swift and transparent,” she said.
“Every delay means more veterans and service personnel could be left without the support they need. Given the challenges in accessing veterans’ records, it’s vital that the government commits the necessary resources to ensure no one is overlooked.”
Last month BBC News used a Freedom of Information request to ask the MoD how many current and former air crew they are aware of who’ve been diagnosed with cancer.
They said they didn’t hold the data centrally, but confirmed in their response that the work to establish the number of people affected was under way.
A spokesperson for the MoD said they “take the health of our personnel extremely seriously and regularly review our processes to ensure that we’re doing what we can to keep our people safe”.
They added that it was “essential that we can assure our people of their safety at work”.
