I flew Whirlwinds for 48 years, 1960-2008, 10's in the RAF, Srs 3 with Bristows and ex military 7, 10's and 12 in civilian hands. l would be flying the last one still but it is mothballed for financial reasons. A friendly old beast and the easiest engine-offer on the planet. However they were also frustrating to fly operationally being burdened with massive amounts of service gear and mods that limited payload to an embarrassing degree on occasions.
The 7's Leonides Major engine was never originally designed to run continuously at 2800-2900 revs and the max boost required in the hover to the detriment of its reliability. The Gnome engine was a bit too delicate for the rough and tumble of sand, salt and FOD that went up the intake, causing the well known compressor stalls (I had two). The engine computor signalling circuits suffered from damp and corrosion that mucked up the signals, all leading to poor serviceability. The 9's, 10's and 12's would have been more capable if Westlands hadn't been constrained to use the existing gearbox and driveline for cost reasons and all the Westland models were about 400 lb heavier than the original Sikorsky S55's when they redesigned them. The cockpit seats were an ergonomic disaster and I still have the back pain to remind me, but I would get back in and fly one like a shot given the opportunity. So much for nostalgia