Cub v.s. Taylorcraft airfoil performance

[astjp2]

Re: Cub v.s. Taylorcraft airfoil performance

There are lots of j-3's in just Anchorage, most have 85's, 90's and o-200's and over half are on floats. Its hard to tell which is a J-3 when there are hundreds of cubs at lake hood, there is a mix of J-3's, PA-11's, and 18's from a quick drive by. Not to mention the L-4's, j-5's PA-12's, PA-14's, etc.

[flyguy]

Re: Cub v.s. Taylorcraft airfoil performance

For those who keep repeating that the Taylorcraft wing will land/flare/stall just like a cub wing if you only fly it right I would suggest they compare the coefficient of lift curve of the Clark Y and the 23012 at the stall point. You will note that the CL for the 23012 drops straight down when it quits. Not so with the Clark Y.

My reading on the data is that the Taylorcraft wing will climb right up to the point of stall if you even ease back on the stick the slightest amount. Then it will drop like a brick. The airfoil doesn't have a "mushing decent" mode like the Clark Y or Cessnas or Luscombes or Chiefs, ect. Are there any other airplanes that use the 23012 airfoil that aren't tricycle geared?

And that is exactly the way my BC12 handles. (and the other two that I owned, and the ones I learned to fly in.) You have to stall it just as it touches down or close enough that the fall isn't a crash. It will not mush down to the runway in the last part of the flare regardless of how slow you are going. And yes I manage to do either a light bonk on or a perfect roller every once in a while, but it is a fight every time.

OK, sock it to me. Chuckle.

I have to get something to eat, way past lunchtime, then I am going to go look, some more, for ethanol proof gasket material.

DC

[Hank Jarrett]

Re: Cub v.s. Taylorcraft airfoil performance

I sure wouldn't say you can land a Taylorcraft like a Cub (except maybe that they both end up on the ground). They require different techniques and a Cub technique will put you pretty far down the runway in a Taylorcraft. That doesn't say that one technique of plane is better than the other except that if a Taylorcraft technique is used the T will kick butt against a Cub and if a Cub technique is used on both, the Cub will kick butt.
They are NOT interchangable!
Hank

You can land either one with either technique, but it may not be pretty, but then, we all look like new students every once in a while. ;-)

[cvavon]

Re: Cub v.s. Taylorcraft airfoil performance

I have a cure for the taylorcraft landing bounce the larger alaska bush wheel tires on my T they get to the pavement sooner then a 600/6 and absorb the bounce not the bungies rolls on smooth there grate

[shipljl]

Re: Cub v.s. Taylorcraft airfoil performance

Here' the airfoil characteristics of the NACA 23012 and the Clark Y airfoils. Notice that the lift coefficient of the 23012 has a abrupt change shown by the vertical dotted line at the point of stall. The Clark Y has a rapidly changing lift coefficient, but no discontinuity. This will make the stall much more abrupt in the 23023 compared to the Clark Y.

In looking at the two curves, I wonder why Taylor would think that the 2312 is better than the Clark Y. At cruise conditions it looks like they are approximately equal with a drag coefficient of about .015. At best lift drag the Clark Y is better, and in the stall the Clark Y is more forgiving. Am I missing something?

[astjp2]

Re: Cub v.s. Taylorcraft airfoil performance

Am I missing something?

Well the airplane will just fly faster and get out almost as short on the same horsepower...it just works!

[M Towsley]

Re: Cub v.s. Taylorcraft airfoil performance

Maybe Cub wings on a BC-12 would prove the point or vice-versa. The Cub is just too draggy, (compared to a T), to do a side-by-side cruise comparison. I thought someone somewhere was doing a Cub wing conversion for Taylorcrafts. I thought I saw it at Osh once. Anyway, the T will walk away from a Cub. CG Taylor did a nice job of cleaning up the BC-12 buy getting the bungees inside, no control wires out on the wings, etc. I think even the narrow fuselage is not as fast as the side-by-side. Just throwing out there what little experience I have with a BC-12, L-2 and flying with Cubs. Kind of fun discussing it, though.

Though I am sure L-4s bit the dust too, I remember the picture of the L-2 at Fort Sill that killed a pilot because he stall/spun at low altitude. It looked like a yard dart. I think the L-4 was probably better at liaison work because of the flat-bottom wing as opposed to the semi-symmetrical of the T-Craft.

[Mark Julicher]

Re: Cub v.s. Taylorcraft airfoil performance

>>>Are there any other airplanes that use the 23012 airfoil that aren't tricycle geared? <<<

Yes.
DC-3, RV-4, RV-8 to name a few

[flyguy]

Re: Cub v.s. Taylorcraft airfoil performance

Ahah. A friend who owns the hangar I use has a RV4 he put together and I thought the airfoil looked similar. He didn't seem to know, but flaps sure must help a lot because he puts that thing on smooth about 95 % of the time. Tells me he has to fight his Cessna 170 some though. His RV will cruise over 200.

DC-3; now that is pretty good company to keep.

On the L/D thing, I notice that the Y is best at about 0 degrees and the 23012 is more like 4. Do cubs, and the other Y's use zero angle of incidence?

We have discussed slipping the Tcraft right down to the ground in order to get the nose up without a zoom, I guess flaps have the same effect?

Darryl

[Acroeric]

Re: Cub v.s. Taylorcraft airfoil performance

Pitts Samson, Beech Staggerwing, and I'm pretty sure the Bonanza's have a 23012 as well.
I've got lots of Cub and Tcraft time. I think either gives you plenty of warning before the stall. Maybe it is just my airplanes but I think one would have to be asleep at the yoke to miss it. I operate out of an 800' strip and find that other than being more precise on airspeed control during approach to minimize float, the Tcraft works out of it just about as good as cubs.

[resojames]

Re: Cub v.s. Taylorcraft airfoil performance

The graphs shown above are not really very usefull for comparison. The chords (thus the Reynold numbers) are off a pretty good bit. One of the big differences in the wings is the pitching down force of the Clark Y which caused a good bit of drag at the horizontal stabIf you look at the center of pressure curves (Cp) you can see how these airfoils differ in this respect.

If these were ploted at the same Renold number you would see the difference in cruse drag.

By the way engineers now are taught to think in terms of pitching moments which remaings in the same spot, aprox 25% wing chord, and only varies in magnitude. You wont even see Cp curves on modern charts.

[shipljl]

Re: Cub v.s. Taylorcraft airfoil performance

Good point about the center of pressure. The Clark Y CP is about 50% at cruise while the 23012 remains at about 25%. That requires a whole lot more lift on the stabilizer, meaning significantly more drag. This would explain at least in part why the Taylorcraft is more efficient in cruise.

[skyboltone]

Re: Cub v.s. Taylorcraft airfoil performance

Are there any other airplanes that use the 23012 airfoil that aren't tricycle geared?
OK, sock it to me. Chuckle.

DC

Beechcraft D17S Staggerwing. (prior to the S model, I believe they had the Clark Y) All the Acrosport Series. Younkin, Dake, and Latrelle's Mullicoupes. Arctic Tern. More.

[Craig]

Re: Cub v.s. Taylorcraft airfoil performance

"They require different techniques and a Cub technique will put you pretty far down the runway in a Taylorcraft. That doesn't say that one technique of plane is better than the other except that if a Taylorcraft technique is used the T will kick butt against a Cub and if a Cub technique is used on both, the Cub will kick butt."


So, what is the best Taylorcraft Technique?

[paulnuss]

Re: Cub v.s. Taylorcraft airfoil performance

The CAP-10B also uses the 23012 airfoil. I took about 10 hrs aerobatic dual with the French Connection folks, Daniel Heligoin and Montaine Mallet, back in 1983. I really liked the CAP-10B, but it was very expensive to buy. I ended up with my (used) Pitts S2A instead, at about 1/3 the cash outlay. I learned to love that Pitts, and owned her for 23 years. The CAP 10-B was twenty miles per hour faster in cruise with 20 less horsepower; was not as strong; had a slightly more gentle stall (harder to snap cleanly!); had very good inverted performance; and glided very far, the airframe very clean by comparison, needing flaps to dirty up the airframe for the usual landing approach. The Pitts was quite dirty already, and lost altitude quickly by comparison. But you could set a down line in the Pitts with full throttle on without fear of overspeeding. I had more fun with that S2A than is the normal human allotment! I believe the clean airframe of the CAP was a good match with the 23012 airfoil for aerobatic flight as well as cross-country cruise.