Mark James Boyd wrote:
...
Can anyone see any reason a DA-C1 airplane could
not be used for soaring badges and records, assuming
the engine and prop were stopped? :-) Sure
beats three rope breaks on tow ;-)

I don't know for the US, but in France the regulation
doesn't allow a pilot flying an aircraft registered as an
airplane rather than a (motor)glider to stop the engine
in flight. And of course the pilot should hold an airplane
license.