DeeMac,
we cannot increase our contributions because of the no decrement clause, and upping our contributions is a decrement, unless as I understand it, every single member of the scheme agrees, which nobody seems to think is viable.
The scheme cannot be altered by NATS due to the legislation unless, there seems to be a C missing, which is, the company does it's best but just can't manage it due to severe financial difficulties or whatever, in which case it doesn't apply.
The current proposal doesn't alter the scheme as you still get the same benefit at the end, that is x 58th's of your final pensionable salary, but now not all your salary may be pensionable, just as AAVA's are not counted as pensionable now.