From the briefings I've attended, the new scheme will not be retrospective as all your previous earnings would be reflected in the pension benefits you would have been earned under AFPS 75 or 05 which will be protected on the introduction of the new scheme. FAFPS will then be based on your pensionable earnings each year from the date of introduction. If you are eligible for incremental progression, such as on the PAS, as the increment would form part of your pensionable earnings your pension would therefore increase accordingly.