Think I've heard of a 400 footer being used here in the US for mine shaft rescue where they couldn't get a crane but I'll need to check my source.
The twilight zone for the civilian helo world is New Zealand so ask your Aussie friend to give you the gen from there. Those Kiwis do any damn thing including linking multiple lines (just for the fun of it) as well as using chains (disaster) for lifting their ****!