Originally Posted by jabberwok
Devised by a doctor at Farnborough who's name I regretfully forget. There is footage somewhere showing him being yanked skyward by a passing Lysander. Early war years I think.
If you have more info I'd be very keen to see that, having just completed a book on the Lysander, and not come across this before.
As a non-scientist and non-pilot, the critical bit seems to be to be how much elasticity in the tow-rope section. Too much and you could whang the glider up the tug's rear, or oscillate across the sky like a caterpillar's 'inching along' manoeuvre! Too little elasticity and any jerk would potentially snap the rope/hook.
I'm sure the physics I'm proposing is more 'Catch the Pigeon' than real world...