Where possible, a trail deployment should be planned to be viable with a single hose, I agree.
However, there were certainly a few occasions during trails when no single hose plan was possible, so the AARC would weigh up the likelihood of a hose failure against the cost of a second tanker. 3 x Jaguar from Lajes to Halifax comes to mind - a single VC10K could support 3 on a two hose plan, but only 2 on a single hose plan. So - did we launch 2 x VC10K with 2 Jags on one and 1 Jag on the other? Or trust to luck that both hoses would be OK and that the Jags wouldn't spoke one of them, launching 1 x VC10K with 3 Jags?
The latter option was chosen; in the event all was fine.
Whereas the trail wouldn't have been possible with a TriStar unless it launched with 2 Jags, dropped them after the final bracket and then turned back to RV with the 3rd. Rather problematic in pre-GPS days and very inefficient.
The A310 software will offer the option of single hose, 2 hose or 'fail-safe' - meaning a 2 hose plan which will still be possible if one hose goes U/S in flight... Replanning an 8 receiver two hose or 'fail-safe' plan to a single hose plan (so that the revised bracket times/positions are shown) takes a couple of clicks and a couple of seconds, incidentally.....
