Sadly, any meaningful FRI at this stage is very unlikely. The Gov is still rubbing its hand in glee at the £11bn of savings (identified) mentioned in SDSR. They've just got NEM and AFPS implemented so no one is about to highlight how wrong it is so soon and the statistical evidence hasn't been properly leveraged (hateful expression, but it works in this case). Whilst last years figures showed a shortfall in some manning areas, they wrote that off as the RAF being "on top of" the required manning reductions; so despite showing a manning deficit of some 2,000, those figures are still above the 2020 requirement so that's all OK - it's crazy, but it's how these things are viewed.
Gov is treating all departments' pleas the same - you have your resources, now you manage them properly. We gave you a very generous SDSR, it's no use coming to us for more (an SDSR that carefully avoided any meaningful mention of manning or terms).
There are other departments that are capable of presenting evidence in public that they are in or close to crisis whilst the MoD cannot - or at least, if they do, they will be put back in their box. The Chancellor still wants to balance his books before the next General Election and he won't want to miss that target a second time. He won't entertain any bleating today.
There is also a line of thought (the central bean counters and the Treasury) that states that if they give in to the Armed Forces (who can't take action) they will run into even more trouble with the Doctors, the Nurses, the Teachers, the Councils, the Civil Service, the Police, the Firemen, the Ambulance Drivers, etc, (can/are/will).
Then there's the leadership - in general terms, comprising some good people in the RAF. The natural reluctance to raise concerns (for numerous and obvious reasons) at senior management, seeming difficulties at higher levels to engage directly with ministers and the ministers' wishes to support the party line all lead to a critical lack of action in this regard. That's nothing new, by the way.
FRI any time soon? Not unless that PVR button starts to go into meltdown. As they've been saying for decades now, "We don't need to retain everyone. There are plenty more that want to do the job." Today's school-leavers who want to be fighter pilots aren't quite as concerned about TOC, pensions, lawyers and the like as those with more years behind them.