After the 74/75 Defence Review, the AT Hercs and VC 10s numbers were a mix of established aircraft (AE) and In-Use Reserves (IUR). For the VC 10, we retained all 13 aircraft, 11AE and 2 IUR - and I fear I've forgotten the Herc numbers. (The 14th VC 10 of the original buy had departed in 1969 to serve as the airtest vehicle for the RB 211 engine and never did return. And I'm pretty certain that, by 1979, the ex-civilian VC 10s eventually destined for 101 Sqn in the AAR role had begun to arrive at Brize, but they would certainly not count for the purposes of this comparison.)