That aircraft could not pull up to Safety Altitude that day because of the lack of icing clearance, the captain said that he could not, to me and others present. You want that on oath?? I was out flying at the same time and a pull up into cloud was not an option for me either. The BOI said a lot of things that you keep quoting, what exactly did I do wrong with MY calculations that day, because Jon and the other members of my formation certainly agreed with me? A standard MK1 Chinook COULD have done it because they had a slightly better icing clearance. It was a long long time ago, but I can remember enough from the day about the weather. From the North West coast of NI, we could see Scotland, viz was good. Cloudbase was low, in limits, but low. It was bloody cold.......
Of interest, another board of enquiry that I was involved in directly, as an accused supervisor, stated that when the crew entered icing conditions, they should have CLIMBED as high as possible in IMC, because icing gets less as it gets colder. Never really got that one, they were in 8000' mountains in winter, but they were a BOI so they must have been right.............