Mark Mather, 51, of Totley, Sheffield, worked stripping and repainting RAF vehicles, equipment and aircraft, including Harrier jump jets, Tornado fighters and the iconic Red Arrows, at air bases around the UK.
In the course of his work, he had to use strippers to prepare surfaces and then paint them, exposing himself to hazardous levels of dangerous solvent fumes, he told judge Mr Justice Ritchie at London’s High Court.
The dad-of-two - who claims he was used as a "human pipecleaner" to strip the inside of a Red Arrows Hawk jet - ended up developing multiple sclerosis, and now blames his disease on his exposure to toxic strippers and paints.
He is suing for almost £5m in compensation, blaming the MoD for ineffective PPE, which he says did not protect him properly from inhaling solvents.
But lawyers for the Ministry of Defence deny breaching the duty owed to Mr Mather and say he waited too long to make a compensation claim.
Outlining the case, Mr Mather's barrister Michael Rawlinson QC said he had served in the RAF as a painter and finisher between 1989 and 2003, serving at several different bases across the country.
He claims to have been subjected to hazardous levels of exposure to fumes while serving at RAF St Athan, RAF Scampton, RAF Coninsby and RAF Cottesmore.
Giving evidence, Mr Mather, who walked into court with a walking stick, told the judge: "Everything seemed to be amusing, we were always laughing.
"It was such a happy time, we all used to sing. Most days I felt light-headed and dizzy.
"You got headaches and felt a bit nauseous - it put you off your supper. These feelings lasted to the evening."
The barrister told the judge the PPE Mr Mather was provided with was inadequate for the purpose of minimising his exposure to solvents, which in some circumstances can trigger the "horrible" disease he developed.
Before 1994, he says he was given only a half-face mask - which was described by some as "useless" - or a paper hood, under which fumes could get anyway.
Later in the 1990s, full-face respirators were introduced but had canisters which were not changed often enough, said the barrister.
And it was only around 1998 when there was a major improvement when a new system was brought in.
However, Mr Mather says that "during no substantial period of time was his exposure nil."
He described how at RAF St Athan, while training, he had to work with dust from solvents hanging in the air "like fog”.
One of the worst incidents of exposure happened at RAF Scampton where he claims he was made to perform an "extraordinarily dangerous" job, acting as a "human pipecleaner" stripping paint from deep inside a narrow air intake in the fuselage of a Red Arrows plane.
"The job was carried out by him because he was the only person who was thin enough to fit into the space," his barrister said.
"He was lifted and pushed into the air intake arms first like a 'pipecleaner' by two colleagues and he shuffled down the intake on his stomach.
"He applied paint stripper in the confined space, wearing only the half mask because there was inadequate space for him to wear the air fed hood.
"After this job was finished he would have 'terrible headaches'."
Mr Mather's first sign of MS came in 2000 when he had eye problems, but he was not told that it could be MS-linked and he was not diagnosed until 2008.
By then he had left the RAF to become a paramedic, but had to give up his new career.
Suing the MoD, he claims his exposure to organic solvents "materially contributed" to his disability, more than doubling the risk of developing it.
"The MS affects all aspects of his life and he has recently suffered a noticeable deterioration in his symptoms," said Mr Rawlinson.
"He cannot walk without steadying himself on something, and regularly falls over.
"He lives in a ground floor flat and 'furniture surfs' to get around it.
"He has a mobility scooter which he used when required.
"His concentration and memory are poor. He suffers with depression and experiences panicky episodes."
However, the MoD is contesting liability for Mr Mather developing MS, with one expert saying he would "probably" have been struck down by the disease even without solvent exposure.
It says there is "no probable, let alone provable" link between his exposure to solvents and the development of his MS and that he cannot prove his risk was doubled.
And defence lawyers are also disputing the MoD breached its duty to Mr Mather, claiming that "suitable and effective" PPE and extraction systems were provided and servicemen were told it was important to use them.
"There was no breach of duty resulting in tortious exposure, because adequate control and personal protection mechanisms were in place," said MOD barrister, Caroline Harrison QC.
"The defendant’s case is that organic solvents have marginally increased his risk of MS, but that on the strong balance of probabilities, solvents have made no difference and he would have developed MS in any event."
The MoD is also claiming his case should be thrown out because it was brought too late after his diagnosis in 2008.
But Mr Mather says he only thought to make a claim in 2014 after a friend had suggested to him that his MS could be linked to solvent inhalation.
The trial continues.