Well ZFAG, in your first post you suggested your grandfather was a technical tradesman and from your statement I took it that his trade would have been: Air Radio Fitter or AR Mechanic (different skill levels) or something like that.
If he was non technical, he could have been the section's stores NCO, an admin clerk or in some similar supporting role.
My suggestion is you get his Record of Service and to do this you need to be the next of kin or representing the next of kin. In your case, I suggest you write to Personnel Disclosures at Trenchard Hall, RAF Cranwell, NG34 8HB and say something like: 'I am writing on behalf of Mrs X, my gran, to request the Record of Service of her late husband Cpl (fullnames) X who died on DDMMYY at RAF Changi'. They will tell you how much it will cost but the information will allow you summarise your grandfather's RAF career from start to finish, including the courses and trades he was in etc.
I know it won't solve how he came to die but realistically you are unlikely to get too much more, unless the Board of Enquiry is still available.
Good Luck
Old Duffer