Thorp Air Command - T18.net

Yep, it was me. After spending 15 years building my T-18, I was still a pretty young man and was "bullet-proof" like many at that age. During my second test flight I was attempting a power-on full flap stall. In retrospect, I used way too much power and the angle of attack was pretty radical when it pitched over violently and went beyond vertical (it felt like I was hanging from the shoulder harnesses) and then stabilized in what seemed a vertical dive directly at the ground. The stick was sloppy loose in pitch and felt like something had disconnected or broken. I had no pitch control. I had started at about 3000' agl and the ground was approaching way too fast. While working throttle, and out of ideas I caught a glimpse of the flap handle sticking up and immediately retracted the flaps - the stick came alive in my hand. I was way, way too close to the ground when I pulled out, and I pulled a few G's, but everything was OK. Thinking back, that flap handle saved this dummy's life. If I had had electric flaps I don't think I'd still be here.

Back at the hangar with my best friend & Thorp hangar-mate, Dean Cochran, we tried to analyze what had happened. I had built my flap detent bracket for a maximum 30 deg. deflection, as I had read, years before that, about the "bunt" issue, but It didn't pop into my mind during the flight. I'm a skinny guy, I had a full fuel tank & nothing in the cargo bay, so my CG was about as far forward as it would ever be. I had put together an 8 lb. tool bag for the airplane, so I put that in the baggage compartment and went to try it again the next day. I had a little less fuel this time also, so the CG was a little further aft. I just couldn't make it do it again. I think the CG and mostly the excessive power is what got me into trouble.

BTW, I would normally use 2 notches (~20 deg.) of flaps for landing, and would slip it very frequently. It felt absolutely solid and comfortable doing that. I flew it for 28 years and I do miss that airplane, and all of you guys. The Kitfox I built is really a lot of fun though, and I really enjoy that kind of flying now also.

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John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

How about a video of slipping with full flaps (30 deg):

https://youtu.be/PBAfEmakFIA

I'll try to do more at altitude, but down low I would not slip indicating less than 90 mph. Might go slower once I play with it at altitude.

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Philip Mandel
N118BC
S/N 957
Beaverton OR

……….” usually a no-go on taking flaps out. …..”

You can surely remove flaps, just slowly is often best and with acceptable speed. I see folks who will fly around level in a Boeing with lots of flaps out and power up seeming fearful to take any flaps out…burning the fuel a Thorp will burn in a week. It’s okay to remove flaps.

Curtis

I do believe that was my comment, I was referring to a forward slip on final in a T-18. I was always told it was a no-go to take flaps out on final, the altitude you lose while taking flaps out on short final in a T-18 could end the flight abruptly. On a go-around, I do agree with you, after reaching my climb speed, retracting one flap setting at a time.

Shack
N921JK T-18C Orig Airfoil - John Kenton built, son Jack owned 26 years, I own/fly now.
N711RF T-18 - Roy Funk built, mid 80s to early 90s I flew about 200 hrs - Sold