Some well informed comments posted-thanks for the info.
Just to clarify a couple of points and please accept that all opinions are given in good faith and correct to the best of my knowledge. I am in the fortunate position of drawing the pension post PVR having passed the 38 point and in civvie employment offering a final salary scheme after 5 yrs of service. I took advice from an IFA recently re pensions and was told that pension law and contractual law are seperate issues ie. at any time an employer can change your pension provided they offer an alternative. Without wishing to thread creep as to wether HM Forces have contracts I believe that any Air Force Act re pensions could be changed accordingly to alter pension rights for those not allready drawing one.
The fact is that in civvie street few employers offer final salary schemes. Most who did offer them closed them to new employees initially before scrapping the schemes entirely causing much bad blood for those who had the rug pulled from under them. Indeed, this issue is the reason Barclay's employees may well strike in the near future, keep an eye on that case for a taste of what happens in the civvie world as the public sector will follow in due course.
The terms and conditions for HM Forces are hard earned and richly deserved. Fight to retain what you believe is rightly yours, a decent pension is high on that list.