Perhaps the 'best' option for the RAF to use their TriStars to Kaubl (or Bagram AFB) and then thereafter...civvy air transprt out of theatre, directly to the UK.
With
our ops, no delays, guarenteed. Double crews (always) solved the duty time 'delay' difficulities.
IE: it is surprising (maybe not
) that that the RAF is knee deep in 'problems'..
IE: when will they ever learn?...