I looked it up today and the line length can be changed, but not in
aircraft.cfg file. It is defined in mission or saved flight file (.flt) under:
[Sling.0.0]
Object=
CableLength=xxx
HoistSwitch=0
It is quite fun to try lift an HummVee with B206... well until you crash, or the engine quits
Bell 214B1 would come handy in this sim.