Stall proofing the Kitfox – Answer found?

[rogerh12]

Esser & Geowitz;

I really have not separated "stall" and "spin" very well in this posting, that's my bad, they really it should be disussed as separate topics in this forum. As for flying with lots of unproven mods, I certainly understand there are builders out there that really just want to make the "factory build" plane in there own home, and that's fine for them. But for me the E in EAA means something special (Experimental), I guess I am just more of the experimenter type (kinda like the wright bothers) and through experimentation improments can be made.

Roger

[jiott]

Admittedly small improvements to stall characteristics can probably be made on the Kitfox, but I agree more with stall/spin proofing the pilot as has already been said. IMHO there are really only two things a pilot needs to become proficient at to stall/spin proof himself: Fly angle of attack and Fly coordinated.

• Stall only occurs at a given angle of attack which is constant for an airplane in a given configuration. It is independent of airspeed and most other factors.
• If you fly coordinated (ball centered) you will never spin, even if you stall.

Jim

[Paul Z]

Stalls and Spins occur when you are flying. If you park it in the hanger , the problem is solved! I all depends on how much you want to fly!

[wannafly]

seeing as parking in the hanger is not an option for me...I read these posts and it gets me thinking about it again. I have a IV speedster with VG on the wing and under the stab. I have done many stalls with my kitfox at altitude in every possible configuration. Differant flap settings, skid ball off to the side, steep turns, power on and off, and have yet to get it to spin. I took a couple of hours spin/recovery training in a cessna 150 so I know what it looks and feels like in a cessna. When I try to duplicate it in my Kitfox it just seems to "mush". Even in a steep turn the top wing stalls first(depending on rudder position) and it seems to just fall ahead. My altitude loss is minimal. If I wait with adding throttle it is maybe 200 feet max. If I add throttle its not even 50 feet. So what am I doing wrong. I ask because I want to find out. I don't want to be on a slow final and find myself spinning in. What am I missing? I would like to know what it feels like to be better prepared if it does happen.

[Esser]

seeing as parking in the hanger is not an option for me...I read these posts and it gets me thinking about it again. I have a IV speedster with VG on the wing and under the stab. I have done many stalls with my kitfox at altitude in every possible configuration. Differant flap settings, skid ball off to the side, steep turns, power on and off, and have yet to get it to spin. I took a couple of hours spin/recovery training in a cessna 150 so I know what it looks and feels like in a cessna. When I try to duplicate it in my Kitfox it just seems to "mush". Even in a steep turn the top wing stalls first(depending on rudder position) and it seems to just fall ahead. My altitude loss is minimal. If I wait with adding throttle it is maybe 200 feet max. If I add throttle its not even 50 feet. So what am I doing wrong. I ask because I want to find out. I don't want to be on a slow final and find myself spinning in. What am I missing? I would like to know what it feels like to be better prepared if it does happen.

If you want to 'make it' spin try a power on stall (30% throttle max)so your engine is naturally torquing the plane to the left. Climb moderately steep to bleed off the speed, as soon as you feel it about to break, kick in full left rudder to help enter the spin and you will have one fun time on your hands. If you do this in a 172 you go inverted on the wing drop. If you use right rudder instead you will counteract the torque from the engine and it will be pretty docile.

Be safe and have fun!

[DesertFox6]

Oooookaaayyy, Alpha Fans; let's take a slow look at this "spin-proofing" thing. At the risk of getting errantly entwined in flight control techniques, I should recap what several have already so succinctly said: "No stall; no spin."

With VGs on board, or better yet leading edge slats/slots on the wing, you're gonna have a devil of a time getting the wing to stall and then KEEPING IT STALLED long enough to induce the yaw rotation required to enter a spin. See the sidebar on page 14 of the March 2012 issue of KITPLANES for a short, spiffy, comparison of VG and slat/slot leading edge technology.

What some of you are experiencing with your VG-equipped birds is a wing that not only stalls at a much higher angle of attack, but also one that re-enters an unstalled state so much sooner than a "slick" wing will, that you don't have time to fully develop the combination stall/auto-rotating moments needed to enter, let alone sustain, a spin. This comment applies equally to "speedster" style tail feathers as well as a "flat-wrapped" empennage but the speedster-style aerodynamics are more effective by design. The VERY short time lapse between reaching the airflow separation point at the VG-altered critical angle of attack and reestablishing usable, controllable airflow over the wing and stabilizer is an effective deterrent to entering a spin...as some of you have evidently discovered.

Again, I'm not going to go into a "how-to" program to force a spin with slat/slots/VGs as many factors involving your individual aerodynamics and CGs will obviate as many techniques as would be validated. Don't wanna go there; that's where "blogging" stops and "briefing" begins.

So, have we found a stall-proofing fix? No way. A spin-proofing fix? Not really, but it will do until we learn more about flight dynamics by flying our own airplanes and getting some of the same high-alpha, post-stall, handling experience our Canadian compatriots get as a regular part of their basic flight schooling. I'm flat embarrassed that U.S. civil flight training programs are so lame by comparison.

Really, I can't stress enough the advantages of taking unusual attitude (aka "upset") training from a credible instructor experienced in aerobatics; NOT one of your local FBO 250-hour, spam-can CFI wonders. You owe your families, your lovingly-crafted machines and your own pink bodies nothing less.

"E.T."

[wannafly]

ET

thanks for the post...it clears a few things for me...everyone have a safe day.