In reply to:
Simon, Not that I would recommend this, but the SR22 flies very well with the door open. The negative affects are limited to noise, wind, which may beget cold interior temps, if both pins are not set, the door may open in the flare, and the possibility of a loss of a knot or two. Also, if it is raining, I would expect a lot of water to get in.
I have decided that if the entire flight is expected to remain VFR and the problem is not discovered until I’m at altitude, stopping to close the door is not necessary.
I have been unsuccessful in closing the door in flight, but I think someone else said that if you slow the plane down to below 100 knots, it can be done. Anyone?
I have one addition to your “negative effects” list: CO. On a flight last year, I was wondering why my Carbon Monoxide detector was beeping periodically during the climb, then noticed that the passenger door wasn’t closed properly. I don’t think the CO level was very high - in fact, I’ve stopped flying with that detector, because it was too sensitive (it beeped so often that I was ignoring it anyway). There’s no doubt that SOME of that CO was getting in, but I’m with you - if it’s a VFR flight, I’ll just point the airvent at my face and continue to my destination.
On that flight, I slowed my SR20 down to 75 knots, but I still could not close that door in flight.