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Short Take-Off.

cubdrvr, I don't even consider the Borer prop to be on the list. Either you have it and are in "the club" or you don't, and aren't. No BUSHWORTHY Cub is without a long climb prop like the 1A175 McCauley (Borer). No offense to you guys that aren't sporting one. Just know that you will be REALLY impressed when you swap out your "cruise" prop for the long blade.

Anyway, here's some photos's of the PA-12 with the Maule wing and LE Slats. The elevators have an additional approx. 2.5 inches added to the chord and span, but still retain the Cub shape. I just put fresh fabric on the rudd, elevs., and hor. stabilisers of this a/c. Otherwise, I wouldn't have known of the additional elevator area without laying a stock one on top for comparison. I like this method of gaining a little area versus the square tails that Sullivan did. Maybe VG's under the stabs negate the need for increased area back there. Anyone have a comment?

12slat1.jpg

12slat2.jpg


This PA-12 had the rear wing attach points lowered to increase the incidence of the wing just a bit more than a PA-18. (for you guys that aren't aware, the PA-12 and -14 don't originally have quite the positive incidence that the -18's have stock.)

This -12 has toe brakes (yuck), 6" extended HD -18 gear, 26" bushwheels, and a HUGE baggage compartment (yes, you could sleep in there).

I've not seen it fly, and didn't even know it existed 'til the owner asked me to fix his tailfeathers. He says it's great, and has no need for an -18. And it's only pushing 150 HP, though he's considering high compression pistons. This is Experimental and he can do what he wants, too, so he's happy.

'nuff said. Let's see if the photos come out?

Dave Calkins.
 
Modified wings

Do you know if the wings were spliced to give longer wing then stock M5,M6 or M7? I would like to know the total length? Do you know what that airplanes empty weight is? Also does anyone know what the distance is at the fuse attach point front spar to rear spar center to center and offset for the Supercub?

Greg
 
Thanks David!

That looks to be the same plane alrighty, It must have been recovered/painted or something as it never looked quite that good! If it is still the same plane, trust me it did perform. I don't remember about what was done to attach the wing to the 12/14 fuselage? If I remember correctly it had manually deployed spoilers (glider type)? I seem to rember the top deck was built up out of square tube also? Did the tail have std. cub flying wires/ jackscrew trim??

Looks like winter has arrived!

Happy New year!

Tim
 
To Greg, our Maule-drvr guest: I didn't measure the wingspan. The owner said it was about 33 feet.

I don't know the empty weight.

Cub spars are 31 inches apart, center-to-center. I'm not positive on offset, but will hazard the guess of "equal".

Tim, Howdy!

The photo couldn't have been airbrushed any better to make that "beast" shine for these photos. It's still a bush beater, but now the tail is fresh.

Square topdeck tubes? I don't think so, but now you have me thinking. I'll check next chance I get.

There are no spoilers on it now.

Yes, finally snowed, and cold to boot. But some more of each would do us well.

Gotta go, Dave Calkins.
 
S2D........I read your post on the washout. Here are my thoughts.....anybody jump in and correct me.........notwithstanding the fact that this would not be "legal" or "safe"(with some pilots) I think a cub wing would perform better with no dihedral and no washout. Without dihedral the wings would do a better job of providing lift at the sacrifice of a loss of some stability. Without washout the wings should also provide better lift and less drag at the sacrifice of losing the progressive stall on the wing.....but, if you operate with one notch of flap at slower airspeeds wouldn't that increase the camber of the inboard wing chord and provide a sort of pilot induced washout?
 
cubdrvr
Sure beats me on the pilot induced washout, sounds good anyway. Agree that no dihedral "should" give just a tad more lift at the expense of a little stability ( yea like a cub has that much inherent stability anyway) But not too sure I agree that reducing washout would provide less drag. If it provides more lift, it should provide more drag. (kinda like the negative notch on the Maule Flaps provides less drag) Maybe I'm just too ham fisted, but I never feel a lot of warning when a cub wing stalls anyway. Just seems like it all goes at once . Maybe I'll have to go take a bunch of washout out of my wings before I go hunting again and see how it works.
 
It sure is great seeing some of the Cub mods that were being done back in the 70's & 80's. I like that wing that Sumner Puttman built. I'm pretty sure the only reason he used an extended Maul wing, was that it just happened to be what he had laying around. Maul wings and Cub wings have the same airfoil. I'm sure his original 12 wings were destroyed in early R&D. I'm not sure about the wingspan on the extended Maul wings. My old 12 with Crosswinds extended wings and Crosswinds Tips had a span of 37.3 ft. from wing tip to wingtip.
 
Piperpa12,

Can you tell me "exactly" what is modded on the 12 wing that you have (buildup by Charly?) I am looking to build a new set next year for to go "temporarily on my current 12" with final destination an 'exp.' 12 sorta?

Send me a PM if you want to send drawings, lists, etc. to [rfamily@starband.net]

Happy New Year!

Tim
 
Right before the site crashed, a picture of black on white modified cub came up on the home page. Photo courtesy of Jerry Burr. Beauty!

I was beginning to think induced drag, structural loads and such when I picked up my mail that had made it to and from Alaska. There is a great article in "Flying" January 2003, page 79 by Peter Garrison on rectangular wings.

Gary
 
Crosswinds Wings

PA12driver,

The Crosswinds modified wing is a host of field approved modifications, approved STC's and modified field approved STC's. I?ll just list the modifications in general. You'll have to sweet talk Charly for intricate details & drawings.

The wings are first completely torn down. Charly then custom fits Atlee Dodge 30 gallon wing conformal fuel tanks. A ton of work is done to the tank bay to prevent the tanks from flexing in the wing. A lot of reinforcing is added around the tanks. Charly also modifies the tank bay to leave the bottom of the tank exposed and flush with the bottom of the wing. Next the wings are extended. Charly uses his own design STC'd extensions. Charly's tips are part of the extension. Then the real work begins; each flap is extended to a full 9 ft. requiring the addition of an additional flap hinge. This mod is done partly under the old Hendricks STC'd flap extension that you can get from Ron Sullivan. Charly uses a multiple field approval to extend the flaps the additional length. The ailerons are then pushed out to the wing tip. Again, Charly deviates from the STC. Instead of moving the compression strut out and moving the bell crank to pull from the middle of the aileron, Charly leaves it in its original location. The ailerons are controlled from the inboard hinge, just like a Maul. Next the leading edges are changed out. Then Charly installs his Crosswinds STOL Leading Edge Cuff adding 1.5 inches to the wings cord. Stall fences are added between the flap and ailerons to prolong the break of airflow during or near the stall. The long flaps and leading edge cuff really work well together. The deck angle used for landing is a lot less. It actually takes a little getting use to. And last but not least Charly installs, by field approval, micro aerodynamics V.G.'s. The reason they are installed by field approval is that with Charly's wing a lot testing was done to maximize their usefulness. The VG's used are the larger ones, like those used on the Maul. They are mounted way out on the leading edge cuff. During testing it was discovered that with full flaps and high angles of attack the cuff performs a similar affect as that of the VG's and would cancel their effectiveness out. After consulting with both Jerry Burr and Charlie White at Micro Aerodynamics, the VG's were moved forward in tiny increments. And to everyone?s surprise the VG's not only performed as advertised, but when installed with the cuff exaggerated the VG?s affect.
 
Hope the information is helpful on Crosswinds Wing Mods for the PA-12! I must have forgot to login, so it posted as guest user.
 
PiperPA12,

Thanks alot! I kinda figured as much on the mods! What is going on now with the situation with the FAA/FA proccess? I will talk to Charly hopefully this week? I am interested in the flap/cuff deck angle situation.

Guess listening to the talk on another tread that we may need to buy a SC to in order to stay on this site (just kidding) I thing?? I guess as long as I keep buying raffle tickets in 50 lot increments that We will still be able to BS with the best of them?

Thanks again for the info!

Tim-- PA12--predecessor to the Supercub. and precurser to the ??
 
Very interesting post. I saw the plane that was on the cover of "Northern Pilot and was impressed and also in aw trying to figure out what all had been modified and why. I'd like to look at it again now that I know a little more. This is the kind of stuff I like to learn about. Sounds like a lot of sweat equity were but into to R&D on this stuff.
 
When I first took my 12 to Charly, he told me to buck-up and buy J.C.'s plane. The primary reason was that the mods it had worked well, and they would be impossible to get approved again, and that was BEFORE the FAA 337 debacle. I sure like that big door.
SB
 
Diggler, Long Flaps:

I think they're great.

Jerry Burr told me there is something better.

He oiled and tufted his wings and found that the full-throttle propwash at anything near and below lift-off speed cones out from the prop tips to nearly the end of the stock PA-18 flaps. Therefore, you have a lifting device (the stock flap) that is in this high speed propwash flow. Now, you put a drooped aileron just outboard of this Highspeed flow in it's own LOWSPEED flow. A highspeed lifting device, and a lowspeed lifting device.

Jerry's question, with it's own answer, is: why would you want to put a highspeed lifting device (a long flap, half in the propwash, half in the slowspeed air) in lowspeed air? It's not as efficient as the above described stock flap and drooped aileron. He said he's not sure if Piper designed it so, or got lucky.

Yes, you will miss the drag of that long flap when dragging it in for landing.

Makes sense to me, But I've been really impressed with a 180HP -12 on a long flapped wing with LE cuff and no VG's. 'Impressed' like the climb angle scared me, and I pushed over more level and throttled back. This thing climbed steep, and it was accellerating.

Did I say enough? Dave Calkins.
 
Yes, obviously the engine is responsible for the climb angle.

That's climb angle is just what sticks in my head about this flight.

When I swapped sticks with the owner, we went out to a tidal mud flat with about ten inches of snow and some ice that the water had run out from under and he dragged this thing in and onto some ROUGH stuff. Yes, we were light on gear and fuel. But put this thing on this surface on 31's, not skis. We HAD to be slow to go in there.

Then again, this guy built this a/c, has flown it for 10 years as it is, and flies all season for his own 135 running 2 float Beavers and this -12 on floats, then 1 wheel-Beaver and ski-12 in winter. He knows how to fly.

Dave Calkins.

PS I almost forgot, the -12's roll rate when flying slow is far better than a stock Cub, and not far from a VG'ed Cub. All this with a shortened aileron. Though the aileron DOES go all the way to the tip, a modified X-wind tip.
 
I hope I didn't confuse anyone on the long flaps. The 180 H.P. is where the steep climb comes from! What I was trying to explain is that the long flaps move the center of lift back on the wing lowering the nose. This is good for landing. With the flaps fully extended and really dragging it in, you can still see over the nose. If you start to lower the flaps without slowing down below 70 mph the nose will pitch down dramaticly. Just the opposite of a SuperCub with stock flaps or 12 with standard length flaps. For what ever its worth, the long flaps do help with take-off. Charly sets the second notch to match the aileron when fully deflected. This set up is probably safer than drooping ailerons. You always have complete aileron deflection no matter what situation you get youself into.
 
Here is my theory on the PA-12 aileron and roll rate.

1) The PA-12 aileron has more travel both up and down.
2) The longer chord allows the sharp leading edge of the aileron to extend below the wing and cause drag when the aileron is up.

Theory on Big V.G.'s

1) Don't need to be mounted as far forward on the leading edge to work, becuase they can start working on the disturbed air from the leading edge cuff sooner.

2) On a stock cub wing you will not see any difference. The nice thing about micro VG's is that if you have a Crosswinds STOL leading edge cuff you get a different set of instructions for mounting them farther forward.

3) BLR VG's will not decrease power on stall speed with full flaps on the long flapped PA-12 wing with leading edge cuff when mounted in accordance with the STC.
 
Pa-12 has a differential belcrank in the aileron control system. Aileron has more up travel than down. Should have less adverse yaw but don't know if this would increase roll rate. Neither 12 or 18 have very good ailerons. Maybe the 12 is alittle better???
 
Sorry guys, all your speculation, and I should have just mentioned that the 180 HP -12 I flew is flying on a PA-18 aileron.

And it's roll rate is nearly that of my Dad's VG'ed PA-14.

Dave Calkins.

Anyone notice how many hits this thread has taken?
 
Up or down nose pitch with flap deflection

The pitching up or down on a cub has to do with the span of the tail in comparison to
the span of the flaps. The air being drawn down over the flaps impacts the top of the
tail in a downword angle causeing the nose to pitch up. As you exstend the flap out
you will reach a piont where you get no pitch up or down. Exstend it farther and you get
down pitch. This point will very some with speed and power setting. To test this for your self take a cub or J3 up and while in smooth air pull down on the aileron cross cable
above your head, nose down. This is hard to do if there is much tension on your
ailerons cables. Caution do not pull hard enough to damage anything.

Wayne
 
Big/Little V.G.'s

Hi Diggler. I sure enjoy your posts. I will try to answer your question of big / small V.G.'s. In the Micro layout, I couldn't find any difference between the two at the stall. In that configuration, the area of chord you are dealing with is so small that the small ones work fine. And I knew that I was going to catch (flack) about the wing covers. So I was happy that the small ones did the job. The big ones are more looks/marketing. On the BLR however, they had to use the big ones. In fact up on top of the spar where they are mounted they would work better if they were 2.5" tall. Then they would work with power and flaps, not just at 0-thrust. They both help the ailerons at approach speeds. Jerry. :wink:
 
Ok so what if any would I gain by putting Charly's leading edge on my PA12 with STD PA18 flaps?

Second, would I get any better flare control with a larger Elevator (Hendrix)?

Thanks,

Tim
 
FOR JERRY:

Or do the VG's under the horizontal stabs. make all the difference, or at least enough to negate use of the enlarged tail-feathers some guys have?????????

And what about airfoiled horizontal stabs???

I saw a thread listed in the discussion index on airfoiled stabs., but haven't checked it out yet.

Dave Calkins.
 
I talked to a guy that had the long flaps on a SCub, and he was complaining that sometimes the airflow over the tailfeathers was disrupted and in gusty winds it was so bad it caused more than a little puckering...Made sense to me, anyway he has gone back to standard flaps. Extended to the fuse of course...
Sound like a safety issue anyone?
Andy
 
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