This is a stand-to for an incoming competition, one of our most expensive yet.
Later this week we're going to be offering the opportunity to Win £270 Rab Neutrino Pro military down jacket
Visit the thread at that link above and Watch it to be notified as soon as the competition goes live
You can see that the 'knee' on the sort of leg he wore (IIRC, the photo is of one of a variety of types he wore) didn't have a large degree of flex. In essence, shifting his backside forward meant that he pushed down on the rudder with a solid metal tube (with the end on the rudder encased in an RAF issue shoe).