Originally Posted by
ORAC
If the RS is 3 hours, as it was for the VC-10 (Bar the many years in the 1990s when there was no dedicated Q tanker support at all) would it need to be fully fuelled, rather than being topped up when called up to RS60?
Your thinking appears that be entrenched in the times before 9-11. An RS of 3 hours could not cater for the UK’s response to the perceived aviation terrorist threat, which QRA is regularly called out for. And fuel on board varies, as does the aircraft in use to allow for flexibility in programming limited assets.