Civilian Wessex
I used to fly the S58T on the southern North Sea while Bristow were operating Wessex (60's I think) from North Denes at Yarmouth. The 58 T was pretty limited on power, just about meeting Perf A standards but I seem to remember that the Wessex had a genuine OEI hover performance out of ground effect which meant it could carry out single-engine rig landings should the need arise. Nothing I flew could do that although I believe that is possible on some Pumas??