Valiant Tankers
The Valiants straight wing was not suited to high speed low level flight which became the favvooured attack scheme in the early 60s
The wings developed considerable fatigue problems which were being addressed but still led to several nasty crashes and the aircraft was eventually withdrawn from service rather suddenly after one such
Your man must have been flying them while these events were developing
One such I think was the Stringer crew at Market Raisen