The suspension of a person under the aircraft on a rope would need a specific CAA permission in any case
Very true.
I've been involved with doing it a few times in the UK in a UK reg machine. We had to be an ME with either SSE at all times or, more likely, flyaway once the "load" had been landed and cut away. We didn't use the SACRU although we could have done with a secondary safety device (send a stamped adressed postcard for details).
All approved by the CAA of course. Not recommended under a single though.
A million years ago, we had CAA permission to carry a trapeze artist on a long line under a 47 - he wasn't attached so it was kind of irrelevent if the engine had quit - he could have fallen off anyway - those were the days *sighs*...