HP90
Retrieve winches would not suit ACO Operations.
Go to the Long Mynd and watch one at work. They are terrific for that sort of Operation but for the ACO setup - no way, due to the amount of aircraft on the ground at any one time (and associated staff standing by them debriefing etc.........), and no way you would operate 2 on the same field............1 retrieve cable screw up and you would have the mother of all birds nests to sort out............
I think H&S would stop retrieve winches on an ACO operation before it even started. For the safety of the students I for one would prefer it that way.
Arc