Series 5 Tailplane stall

[av8rps]

After flying a multitude of Kitfoxes and Avids for over 25 years, and doing just about anything you can imagine with one, I believe that this situation was likely caused by a tail stall, and not the flaperons.

Unlike many that think our flaperons are useless, I use flaperons for every takeoff and landing (I've adjusted my flaps so I get nearly 30 degrees of throw). And yet, I've never experienced anything that I would say is unusual or scary.

Here's just one example of the extent I've tested my flaperons; I recently blew out (!) both back quarter windows on my Kitfox amphib while practicing SEVERE full flap slips in both directions in an effort to figure out how to land my speedy little amphib shorter. (I began the testing at high altitude to be safe. I didn't want to learn at low altitude that my severe fuselage angle combined with a slow airspeed, a huge sink rate, and totally uncoordinated flight would result in something like a snap roll). But even in that situation, the Kitfox was solid and stable.

Oh yeah, I have also mistakenly had my flaps on as high as 100 mph and never had an issue. Once the flaps actually took themselves off from the air pressure caused by the speed.

So I think you hit the nail on the head when talking about the tail stall.

Thank you for sharing this information Jeff. It is very good for all of to know. And if it happened to you, it can happen to others.