Jimmie

The wire cutting through the magentic field will generate an EMF - a
potential difference between one end of the wire and the far end but
there is no complete circuit to tap it. If a return wire were
connected to the far end of the wire, it would generate the same value
and polarity giving no net emf (voltage) around the path. If one
could create a loop and rotate it in the field that would be a
different matter. The same concept applies to the voltage developed
between the wing tips of a (metal) aircraft.


My post was about a possible trailing loop. (Both ends accessable to the ham
on board.)
You don't have to rotate the loop - just to move it.
The aircraft is moving - thus the magnetic lines get 'cut' so to speak, so
emf gets generated.
I also heard it worked 'too well' on the shuttle - that the current was so
great that the wire burned into.