2 stories:
1. IMC training in a C172. Door opened as I lifted off, under the hood. Continued with takeoff, commenting to the instructor 'my door's opened'. 'Well, shut it then when safe to do so' he said. I'm DARNED sure I'd latched it locked before takeoff. I'm PRETTY sure he'd reached behind me and opened it. Door closed easily when we'd attained the cruise. Cessna doors are easy to open and close in flight Good lesson. On another flight he also had me takeoff (again under the hood) without me personally carrying out a walkraound, claiming he'd already done it and we were in a hurry. As I climbed out, the ASI started to decrease. I checked the revs and attitude, both good continued the climb and reported loss of airspeed to him. 'What are you going to do?' he asked. 'Level off after a suitable interval, declare an emergency and try to return to the field'. 'Fair enough, take off the hood and return to land'. After we landed, he showed me the 2 pieces of tape he'd put over the static vents. I must confess that I don't actually do any of this stuff with my students, but I DO talk about it so I guess the lesson gets passed on.
2. My wife was PIC in her PA28, I was pax in the right seat. Hot day and I opened the door as we backtracked the runway. I pulled it shut as we turned around at the end. Just as she lifted off, it popped open. I'd forgotten to secure the top latch. 'We've got to go back!' she exclaimed. I said we couldn't as the airfield was closing as we departed. I tried and failed to close it again so just left it trailing in the slipstream. Absolutely no effect on the handling but a bit noisy my side. The fallout was mighty, though and ten years on it's still brought up in conversation from time to time.
I've flown Cessna Aerobats with pins in the door hinges, in case you want to exit the aircraft whilst wearing a parachute. I'm sure they wouldn't do that if the thought the door was going to hit the tail. On the other hand, if you feel the need to take to a 'chute, then you might not be worrying too much about the aircraft once you've left it.
Now, as to unlatching doors before landing. This is something I DO teach in the event of a forced landing, where the fuselage might get distorted and the door would get jammed. Otherwise, they're firmly latched closed for a normal landing.
TOO
TOO
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