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View Full Version : My Agenda...STOL...



ackselle
03-10-2012, 08:49 PM
Help me out guys..... I've got a Classic IV, with a 912F and a Hoffman CS Prop, Nanco 21x12x8 tires... I'm at 653 lbs empty.

So.... how do I reduce my STOL speed? While there are slat alterations available, are there any commercially available .... Are there any alterations without alterations to the wing available?... that would improve STOL? I don't mind giving up cruise speed.

Talk to me. Let me know the possibilities. My hine runway is mud for the next 6 weeks, so I've got some time. What do you recommend?

Oh.... and BTW.... I'll be in Fairmont Hotsprings from June 10-18., with time to fly!!!.... wannafly and kitfox2009.... I'd like to touch base before then so we could meet!

Cheers,
Ackselle

Av8r3400
03-11-2012, 06:14 AM
Ackselle-- how slow do you want to go? The wing, engine and airframe you have is already an extreme STOL setup.

My IV with a 912 (640 pounds) will fly with flaps down at 35 mph.

At this point the only real effective measure would be to put your plane on a serious weight reduction plan.

cainbird
03-11-2012, 07:32 AM
I have always wanted to cut a pair of flaperons in half so you would have regular flaps (capable of say 35 or 40 degrees). The outer portion of the flaperon would become a regular aileron. My head tells me this would create more drag because you could pull a lot more flap angle in than you currently can with flaperons.
I will be the first to admit however, my head has been wrong in the past and I am not about to chop my plane up to try this un-engineered idea. Mabey an old bone Model 1 would be a good test bed for such a crazy idea! Any willing test pilots?

Cain B

jtpitkin06
03-11-2012, 08:21 AM
The Kitfox is already a STOL aircraft. Although there is no official definition STOL is generally accepted to mean an aircraft that can takeoff or land over a 50 ft obstacle in 1500 feet. The Kitfox easily qualifies.

So, just what is your objective? Do you want to land in 300 ft or 185 ft?

Flying circuits at Kitfox approach speeds is fun in calm conditions, but what happens when the wind starts to blow?

As stall speed decreases, so does the ability to handle surface winds. A rule of thumb for max crosswind is 33% of stall speed and max headwind 50% of stall. For a Kitfox with a 35mph stall that's about 12 mph max crosswind and 18 mph max headwind. It's not just the landing that limits operations... don't forget about taxiing. Try taxiing a Kitfox around a crowded ramp with 18 mph winds. Now that's "sport flying"!!!

The above rule of thumb estimates are for average pilot skills. I know some of you non-mortals with golden hands and brass huevos have landed in gale force winds on a picnic table. But as you know, you are a rare specimen.

For the rest of us, if you lower the stall speed much below 35 you might limit your flying to nearly calm wind days.

John Pitkin
Greenville, TX

DesertFox4
03-11-2012, 08:43 AM
Vortex Generators? Some have had good success with them. Some only marginal. One of the best V.G. kits with the best results is available from Kitfox Aircraft LLC. http://www.kitfoxaircraft.com/

And cainbird - your idea has been discussed many times in the past
just not on this forum yet. ;)
Lots of hurdles to overcome and most likely why none exist. My impression from better minds than mine was that it is probably
easier to design a whole new wing to accomplish your concept.
Flaps on a Kitfox sounds like fun.

DBVZ
03-11-2012, 08:44 AM
Do you have VG's on it? You will need about 120 on the wings and 80 on the under side of the tail. Not an expensive addition, and they weigh almost nothing. Installed correctly, they should improve stall speed. If you look at STOL competitions you will see that they are pretty much standard for STOL.

catz631
03-11-2012, 08:49 AM
VG's on my bird did squat other than look cool and add a little bit of stability at low speeds. Others have better results I guess.

Dick

Newkid
03-11-2012, 09:49 AM
What exactly are you looking for? Shorter takeoff, shorter landing, both? What kind of numbers do you want to see?

ackselle
03-11-2012, 11:42 AM
Thanks guys.

More than anything, I just wanted to get a conversation going. I'm more than satisfied with the STOL performance of my IV. It seems the CUB guys spend an pile of cash trying to reduce both take off and landing distances.... then they go to Valdez to show off. Why don't we see any Kitox respresentation up there?

BTW... I found it easier to put me on a weight loss program.... my climb rate improved dramatically when I went from 235 lbs down to my current 182! Now if I could only remove 53 lbs from my plane. Hmmmmm.

Newkid
03-11-2012, 02:54 PM
I've heard that up at Valdez in the experimental class the planes gross weight has to be more than 1320 lbs. That's to keep our type of planes from thumping on the Cubs. Paul Claus always seems to beat out the highly modified Cubs up there, and all he has is a 160 horse Cub on an extreme diet with VGs, and tons of hours flying it. As far as slats go everything I've ever read said they will slow down but all you can see on final is the sky.