Originally Posted by
WHBM
There's an STC mod for some Cessnas with a top-hinged in-flight operanble door, which when released goes up by aerodynamics to under the wing, and can be pulled back afterwards by the pilot by a cable.. I've done a good number of jumps from C180 G-BOIA which was so equipped.
Yes, it's a common mod on both 180s and Skylanes used by jumpers.
I'm not aware of any equivalent upward-opening door for the 172 (it might well foul the wing strut), and photos of G-BNYA certainly show it has a conventional forward-hinged door of the type that jumpers (reportedly) don't like.