Re: Reliability?
Four were due, 5 take off, no problems with the 4 due to make the crossing so the spare turned back.
It was a similar plan which saw Martin Withers in Vulcan XM607 as reserve aircraft take over when XM598 developed a fault and had to return to base during Operation Black Buck 1. The original plan was for XM607 to return to base after the first refueling.