Morpardave
Allegedly our pension is non-contributary, but then on the other hand the MoD are quick to point out how much it is worth in the amusing Armed Forces Benefits Calculator.
This tries to tell Armed Forces Personnel what a great deal they are on by pointing out that they get such things as "free" gym membership (in reality this is in the MOD's interest to keep us fit), "free" dental care (in reality we need to be dentally fit or our teeth will blow out with large aircraft pressure changes), "free" medical care (in reality we need aircrew medicals to be able to do the job they want us to do), etc...
The Armed Forces Pay Review Body take into account our non-contributary pension in their pay award. So overall, it's all a bit of a con!
You can pay additional contributions to boost it and quite a few do.
Finally, if you were to draw comparisons between Armed Forces and Emergency Service pay, then I believe that a Rating/Private/Leading Airraftsman is paid less than their Emergency Service counterpart - which would indicate that the Armed Forces Pension is actually a compulsory contribution!
The B Word