Re: Just one thing I don't understand...
What I don't get is this: why 'throw' them down?
It sounds like the sandstone blocks are heavier than what you could easily hold while being hoisted back up into the heli, and getting slings or a net around one requires that you can move it about a bit. Which probably is somewhat hard to do when the block in question is embedded into the side of a steep cliff: once you've sufficiently loosened it, it will succumb to gravity and end up at the bottom of the cliff. And with smaller rocks you probably don't want to be winched up, and then back down again, every time you have collected 20..30kg worth of rocks. Much quicker to chuck them, especially when you have to collect the larger ones from down there anyway.
'Throw' might be a wacky translation, or maybe you throw the smaller ones away from the cliff side so that they actually land at the bottom and not on some ledge halfway down.