Just to be pedantic it's not specifically RAF (all aircrew carried this type when I was supporting the Army Air Corps back in the 90's), nor survival in the 'living off the land' sense. It is a 'rescue' knife for cutting one's way out of entanglement - the 'MOD Survival Knife' is a very different item.
I've always considered this type the 'Mark 2' (although not sure if it has a Mark) as there was an earlier version with same hilt but with a 'proper' blade (& that might not have been the first). This style of curved blade was to reduce accidental injuries & is not very effective beyond slicing webbing etc.
More recently the type shown have been replaced by a hooked 'seatbelt cutter' - further demonstrating the purpose - not a popular change!
The more 'exciting' tales of their user come from the sheath & hilt being visible on black overalls in well known pictures of the SAS at Princes Gate. Not to say an individual paratrooper couldn't acquire one somehow ... but their official usage is as an aircrew rescue knife.
Edit: If I'd not rushed I'd have noticed that was a link before, & noticed not everyone's calling it 'RAF'. Most of what I've posted was on the other website too (& including pictures of the other types)!