Does anyone have a copy of Nexus Psi where this rule was printed? All the various sources I'm finding out on the web seem to be slightly different, probably as the rule was published in a few versions during play testing and is too long to easily summarise in a line on cheat sheet.
A different ref sheet I found says you do need to be able to see the sky with the firer as well (logical). Also that you can't fire at less than half range which wasn't on Mike's sheet I think. Wouldn't have stopped me firing tonight but nice to know somewhere on the battlefield is safe!