Wasn't operating on this one (supernumerary crew/BCR pilot, RWR-watching on the jumpseat) - longest unrefuelled flight in a Chinook was 10h 30m. At least I was able to get up and stretch my legs in the acres of space between the 3 Robertson tanks in the cabin, unlike the HP/NHP. Not that the cabin was much better - all hatches open, which meant that the gunners (there to provide cover if we'd found who we were looking for) had to be carried off at the end of the sortie. OAT MS03 plus 120 kts through the cabin makes for some serious windchill.