I haven't yet seen this letter, but does it mean that any flying tours completed as a pilot (RAF crewman rates) don't count at all?
I was a second tour pilot once, and when I qualified as aircraft commander I reverted to first tour commanders pay, only for a few weeks, but I actually took a pay cut for being better qualified. However after 4 years from first payment of flying pay I went onto second tour commanders pay. Has this now changed?