I thought this article might be of interest here in Rotorheads:
Virtual Bob « The Space Elevator Games Which describes a way of keeping a cable taunt between a helicopter and the ground.
and
Test Flight Results « The Space Elevator Games Which gives the flight test results.
Appologies if this technique is old hat to those of you who fly for a living, but to me it looked like an elegant and practical bit of engineering thinking.
Memetic