old dilemma!
Great question K set! A classic!
SOP is probably the only answer, the two verbal advice and so on..
Would 100ft be enough? I can't think of dozens of episodes and grey situations, different characters, cockpit gradient and many others factors.......that's probably why most of us are still looking for a proper answer!
My answer is do something sensible!...You can always talk about it in the bar!
I read something about an experiment setting up different crews in a similar situation, maybe usaf c130S? not sure, apparently in most of the cases they crashed.
Cheers