Once again H2S = V Bomber = Vulcan
In fact the H2S equipped Victor K2 was in service till 1993, many years after the Vulcan left the service, post Falklands (558 had its H2S removed, I believe). So it would be at least plausible that the ACAS, who is an engineer who entered the service in 1988 might have had a Victor background, although in fact he was a Nimrod/Tornado man in the days when he was still getting his hands oily.