Skyhook
As I recall, the flight trials associated with Skyhook consisted of hovering a Harrier beneath the jib of a crane, and demonstrating that it was possible to maintain a spot on the wing centre-section within a 10ft cube of sky - the theoretical 'capture window' for the hook. There was never any hardware to connect the crane to the aircraft, much less recover or launch it.
Perhaps a bit of a stretch, then, to say that it worked well in trials, not that it wasn't a good idea. The person who thought of it was Dunsfold TP Heinz Frick.
Rhys.