Very sad news. Condolences to Jean and family at Rhosneigr.
He wasn't always at Valley. I first flew with Doug in 1973 when he was instructing on the Varsity Refresher Squadron at Oakington, having moved from Strubby.
Some time later I was doing a Hawk air test with him at Valley when he decided to do a supersonic run -- something that was not taught on the FTS. We dived over the Lleyn peninsular -- Doug having assured me that the Hawk did not make a bang. When I later repeated the exercise, I always made sure I was over the Irish Sea, just in case it did!