The Hiller was flown by one of my RN instructors, Terry McDonald (sp?). Terry started as a RAF fixed wing pilot, moved on to fly a VC 10 for the Nigerian president at a time when they were being removed rather frequently. Terry used to joke " Whose the president today?". He then joined the RN to become a helicopter pilot, was a great character & good instructor.
Apparently the weather in Paris was very bad & while flying just below the low cloud base, something broke & the Hiller pitched upwards into the cloud & reappeared virtually upside down, crashed & killed him instantly. Hiller of course said it was pilot error & that Terry had lost it in cloud. Having had an instrument rating in both planks & helicopters for 20+ years, I highly doubt it. Very sad loss.