Sad, sad news.
After seeing Dennis' exploits online, I got in touch with him via PPRuNe.
When I eventually made it to the UK, he very kindly arranged for us to fly together in a Hughes 300 belonging to a friend of his. We spent a delightful afternoon in 2012 flying in to Shoreham for generous helpings of sandwiches and engine off landings, followed by more tail rotor failure stories than any one man deserves.
Thank you again for for being so generous with your experience.