“Only a little resistance, really, at least for the first 12 inches or so.
If it’s one of the older Colts, with a cruise speed of under 100 knots, cracking the door could cause a stall if you aren’t watching out for it even with a stall speed at 47 knots. My father learned to fly on one of those. As a two seater it is a good small aircraft to work with an instructor. But Piper never built them for speed. At least not with a 108 horsepower motor. But they are economical. I’ve seen grand transpo with bigger gas tanks. Tri or tail dragger?
wy69
Nose gear. Opening door doesn’t affect airflow over wings. More like a speed brake on one side. Stalling in the Colt was basically a mushing thing anyway. I did learn spin recovery in Aeronca.