Spin. Engine quits. Why?

[scsmith]

In Marabou's video, it is pretty remarkable how quickly a uniform, fully developed spin developed. Maybe 2-- 2.5 turns, and no nose bobbing from the spin axis being inclined.

Oh and Marabou, your english is fine.

[sandifer]

Originally Posted by Marabou

My main question is regarding your advice to go to full throttle before rotation stops. I’ve got some flat spin training with three different instructors in other “a bit more aerobatic” aircraft then RV. One way to enter flat spin I learned is just go to full throttle right after you entered regular spin. Plane immediately raises the nose and here you are. I tried it in RV but did not succeed. Actually I couldn’t induce flat spin at all using any technique. Possibility of flat in RV had been discussed here earlier. My guess it is nearly impossible at least very difficult due to nose heavy nature of RV.

Yeah, full throttle applied in conjunction with the recovery rudder can help stop competition spins more crisply. No need to do this with recreational spins unless you just want to see how your plane responds.

Regarding flat spins, I assume you know they only really work when spinning left, assuming a Lycoming motor. I never tried one in my old RV-3, but I've seen video of an RV-7 doing a nice looking flat spin like any other aerobatic airplane would do. Once the left spin starts, you apply full right aileron and full power, keeping the stick back. In most aerobatic airplanes, unloading the aft stick just a little will stabilize and accelerate it slightly. Be aware that high power flat spins apply high gyroscopic stress to the crank/flange...something to be aware of if you're running a metal prop and a light and/or hollow crank and do a million of these over and over. If not, don't worry about it.

I noticed you applied left aileron a few turns before recovery. Not sure if that was inadvertent, but you can see that it accelerated the spin slightly, and may have delayed recovery a little. Not exactly "proper" technique, but you seemed to have a handle on things and plenty of altitude, so no problem.

I've gone dead stick a number of times doing spins in the Pitts. In my case it was a low idle (light Catto prop) issue rather than a fuel issue. Not so much an issue with a metal prop due to flywheel effect. I got used to blipping the throttle as needed during spins and tail slides once I was able to start counting blades. With wings tanks, you can of course unport the fuel depending on fuel level.

[Marabou]

Originally Posted by sandifer

I noticed you applied left aileron a few turns before recovery. Not sure if that was inadvertent, but you can see that it accelerated the spin slightly, and may have delayed recovery a little. Not exactly "proper" technique, but you seemed to have a handle on things and plenty of altitude, so no problem.

.

I did it unintentionally. Caught myself several times making this mistake earlier but it happens sometimes again especially at recovery. It really feels like rotation is different if some aileron deflection is involved but according to my measurement rate of turn remains the same or within measurement error.