They don't get penalised - they get extra money that is over and above their basic pay.
What a load of rubbish people speak about flying pay.
Flying pay is simply the money you have to pay aircrew to recognise their skills, and to recognise the money that they could be paid elsewhere.
As such it should be fully pensionable, and you should not be able to reduce it if someone decides to leave the service giving significantly greater notice than they would be required to give in civvy street.
Of course it will always cause resentment (buying a sports car! what depravation!) amongst those who dont have similar skills and potential earning power.
