The following was extracted from the article about the rollover of the Super Puma in the North Sea.
The passages are not in the order of their occurrence in the article. I changed their order for journalistic juxtaposition.
“The rotor blades were still turning as the Super Puma helicopter rolled and it is understood one blade struck the co-pilot, breaking his leg”.
“According to a spokesman, the West Navion was pitching and rolling between four and five meters. A westerly wind was blowing at 33knots-gale force seven to eight – and visibility was 4,000m.
"If it was sitting steady on the deck I can only imagine it was pitch and roll that caused the problem."
This may very well be a case of dynamic rollover but is there a possibility that the pitching and rolling effected the stability of the rotor system?
We had a similar situation on an icebreaker with our S-51s. What kept it from rolling over was that it was tied down during start-up and released as the piliot pulled collective. If the movement of the helicopter was violent enough we would release and the pilot would clear the deck by pulling collective.
This will be my last input on this subject.
Of course my fingers are crossed.