Short Take-Off. [Archive]

Jerry Burr

11-28-2002, 04:48 PM

Denny's Cub is Experimental, and he has a lot more lattitude than most of us do. It has a long wing / squared ends/ Demer tips. Long droop ailerons. Semi stock flaps, extended to fuse. Big tail. Little tail wheel. Atlee's big tanks. 30" airstreaks. Micro V.G's And lots of little stuff. Now the good stuff. Denny used to be a drag racer, need I say more? It started a 180hp. Shaved the cyls 3 or 4 times. Flowed. Equal length headers, 4 into 1. Ellison body F.I. . The big kick is the 150hp NOX kit. He is using welded in Foggers. He jets to the occasion, for the power needed. And a very long, very flat prop. The reason he isn't using much flaps in the video was time. This was taken a few years ago and has been improved upon since. I had built him a Low speed airspeed like mine. The problem we discovered was that he was accelerating faster than the airspeed could accruately read. Now he more or less rotates from brake release. We are kind of in the same spot now. Since Gulkana closed their doors, there is no reason to actively push research in this area. Why spend the time and money to train a good horse if there is no track to race it on? I have tried to get something going in Montana that woud be centerally located that everyone could attend. The heavy touring classes always drew a great crowd. And truly dedicated fans. If anyone can get something of the Gulkana class going, we would be more than willing to gear up and attend.
Here are a couple clips of my White Hawk Cub. They are longer, one is take-off and the other is landing. Enjoy. Jerry
http://www.supercub.org/upload/Mov5.mpg
http://www.supercub.org/upload/Mov11.mpg

Cub junkie

11-28-2002, 05:02 PM

Jerry I was wondering what Denny does with the timing on the Lycoming when the Nitrous is put to it? I have used it in Automotive applications and we used a timing retard electronic box(which was supplied by the nitrous kit people) to take advance out of the ignition,otherwise you can turn good parts into scrap real easy. I was present at a drag race where a guy had a timing failure and the engine pushed both head gaskets out on a chevy engine. just wondering......

Jerry Burr

11-28-2002, 05:13 PM

I just noticed a couple of things that I did not answer. For everyday use both of us are off in under 100 feet. On landing, the approach and touchdown are precision, but we both ignore the brakes. I have stock brakes with the 25" tires and just don't use them unless I have to. You might notice on the video we land with the brakes (ON). On takeoff I feed the power in very very slowly if it is the first takeoff of the day. If the engine is hot it's smile and go. My takeoff in the video is 30'. The landing is 65' My best takeoff during practice on Saturday was 17' and landing was 24'. It's hard to match practice with actual. Jerry.
I just noticed a new post. He resets the timing upon arrival. The new (non magneto type ) ignition system people have agreed to make a push button retard in their system if we want it. It just takes money. Jerry.

supercub

11-28-2002, 09:26 PM

Thanks Jerry for the Vids............loved them..if you have more.please post. they're great. Those TO's are amazing..........so was the landing. Best I could tell there wasn't much of a wind blowing either........looked to be about 5kts or so. Thanks again
Brian

S2D

11-29-2002, 06:11 PM

Jerry:
I would love to be able to get off around 100 feet consistently but my big question is: What do you have to sacrifice to get that kind of performance?
I need an aircraft that is hightly manueverable at lower speeds to keep up with a coyote ducking and dodging up a coolie and still be able to land and pick him up in any condition. (light or heavy, dry dirt or deep snow.)
only three things I've found so far that will help a stock cub is 1. get the best flying cub you can. this may take a lot of rigging trial and error or lots of plane trading--2. use the longest, flattest prop you can get attached --- and get everything out of the cub you don't absolutely need. this even includes a gunner. ie do it yourself. Maybe extended flaps or independent drooped ailerons would be ok too but i don't have any thing to base that on. Problem with no gunner is one less set of eyes but you can sure pack a lot more coyotes. What other kind of mods improve takeoff capabilities without decreasing maneuverability or dependability? Oh I almost forgot. convert to 160 hp too.

Jerry Burr

11-29-2002, 08:08 PM

Hi S2D. That's a tough question to answer in front of a thousand Cub types. When you get spare time go back over #1,#2,#3. You are on the right track. Beyond that I would square the tips and put on Ron Sullivan tips. Push the ailerons out to the tips. Ron has STC's for both. Extend the flaps into the fuselage. ( the screw on's are fine. ) You will still have good aileron control, and good visibility. I assume you already have Micro V.G.'s. I can fill in the blank spots if you contact me via private mail. Jerry.

CubCouper

12-02-2002, 12:13 AM

Jerry (or some of the sheep hunter types) might be able to help me out here...

I see these vids of spectacular performance and know that it usually involves a healthy dose of experience and special mods. And some of the AK pros casually mention 400' strips at gross like it's all in a days work. I was shooting some landings on a local gravel strip the other day and decided to step off some distances. I was using around 400-500' of runway on takeoff (48g of fuel, otherwise light). My SC is basically a stock 150, no VGs, 74x50 prop. Living in Colorado, I've only got a handful of takeoffs and landings below 5000'. What are reasonable numbers for high elevation airports? What kinds of performance gains could I expect to see by switching to a long prop or adding other performance enhancement mods? Some day I will switch props and add VGs, otherwise I'm actually most interested in some hard numbers for altitude-induced performance differences, since my Cub is mostly a cross-country fun machine.

cubdrvr

12-02-2002, 08:46 AM

Rod.........I think most of use would agree that you will see the biggest performance increase with the Borer prop. I would conservatively estimate a 20% decrease in ground run. That is based on Midwest flying..........not sure how the prop performs at altitude.

pak

12-02-2002, 06:23 PM

C-couper, I'd say your numbers are very respectable. When someone tells me that they can do 250' I generally ask which 250'. I think the best pilots are able to pick a touch down point and keep it in sight until the plane hits. For me, it is not too hard to hit close to a big white spot on a sand bar or gravel runway with good approaches, but keeping in sight a touchdown spot on an otherwise fairly obscure strip is the real test. Keep on truckin'. pak

Ikatan

12-03-2002, 02:07 AM

PAK raises a good point that I agree with. Landing short consistantly, even on a pretty short strip, but that is easy to see is only part of the skill. My experience has been that putting it on a spot and stopping short is not so hard anymore, it's finding the right 250' and keeping it in sight in a large area that pretty much looks the same as you keep changing perspective while going around that's tricky. If there happens to be something large and obvious close to touch down spot, great, if not it's harder. There are large open gravel and cinder areas around the volcanoes here like that. Lots of landable spots interspersed with big rocks, but at a short distance on a low approach, it all blends together and is a challenge to keep focussed on the right spot. The other thing, I guess, is having the spot obvious enough but having to maneuver around close terrain, trees or whatever to get to it.

CubCouper

12-03-2002, 10:48 AM

From the day I picked up my cub I started working on spot landings. Even on the home airport with 2 miles of pavement I try to touch the mains down in the last few feet of the big white blocks. In college I shot on a competition rifle team... the coach was adament about aiming for the center of the 10 ring and not just the 10 ring itself. I try to use the same strategy in picking the spot on the spot where I want to land. After seeing Jerry's clips I still think that I'm a little too fast on the short approach and flair. My justification has been that the 5000' elevation makes the groundspeed higher. With my current technique, I'm usually pulling most of the power off in the last hundred or so feet of the approach. My guess is knocking another knot or two off the approach speed, and maybe "dragging it in" with a little more power would give even better spot control and a shorter rollout than what I'm getting.

Ikatan

12-03-2002, 09:20 PM

I think you're right... the more you can slow things down the easier it seems to put it where you want it. Working close to the edge is something that needs to be approached carefully, of course. I find also that it helps to not think of it as "dragging it in with power", but rather "controlling my descent with power", notwithstanding what instructors hammered into me long ago. Potts book on bushflying techniques is good if you haven't read it already. "Operating" an airplane and "flying" are different, in my opinion.

PA12driver

12-04-2002, 12:00 AM

Rod,

As Rush would say--"mega ditto's" I was taught that if the windmill quits you should still be flying not stalled! that works in a perfect world and most of the time that is possible in a cub. It is a fact though, as stated already that what is of equal importance that we touch down and 'stay down' and be able to stop in the shortest distance with the least amount of braking! To do this consistantly I believe all of us would agree that with a realitively stock cub you will be better off carring a little powr and "controlling the decent rate". The further out you can get set up the better. Jerry's video shows that quite well!

I have lots of time in a Supercub and only about 300hrs in a PA12 and I am having to relearn the game cause the deck angle is so high on approach that I have to add power in order to get it slowed down! To me it feels much like I used to fly my 185 into short strips!

As with your rifle shooting "take two breaths let one out and then 1/2 of the second one then squeeze her off (or in the case of your cub)queeze her on!

Practice, Practice, Practice

Tim

supercub

12-04-2002, 08:57 AM

A Good landing, is the direct result of a good approach and that's applies whether you're landing after an ILS or a short, rough, off field landing. Plan things out, well in advance, have a good stabilized approach if possible, and keep your options open, unless you don't mind bending your bird. I totally agree with Tim.......practice, practice and then practice some more. Play it safe
Brian

cubdriver

12-08-2002, 09:56 PM

Unless I missed someone mentioning it, there was a considerable wind factor that day.

Seams like I remembering it as being close to 25 - 30 MPH. Probably us regular Cub jockies could break ground in under 50 feet with the same conditions.

I'm not being critical, it was a great T.O. Way better than me.

Jerry Burr

12-24-2002, 12:45 AM

Hi Cubdriver. I don't know which part of the crowd you were sitting in that day, but I have never seen a 20mph wind at Gulkana in all of the years that I was there. OK I take that back. There was one year about 2:30 in the morning. But let me try a different prospective for you. On Sunday afternoon it was warm and no wind. The top 4 airplanes from Saturday were competing in the Super Bush Challenge. Everyone was carrying 400 lbs of ballast. The average distances were 230,223,227,225 feet. In the Modified Super Bush Challenge there were 2 airplanes their average distances were 154 and 76 feet. You have to be standing next to it to believe it. Speaking of which, what we really need is a Contest in the center of the lower 48, right about where you are. Do I hear a volunteer? Jerry.

Dave Calkins

12-24-2002, 09:55 PM

Hey, I'll just hop in one of the Cubs, throw in a piece of caribou jerky and a pint of water and head on over for THAT competition.

Sorry, Jerry, I just wish it were so easy to zip on over and say hello to you guys.

Merry Christmas.

Dave Calkins

PA12driver

12-24-2002, 10:04 PM

Heck David,

It isn't that hard, I brought the Freightliner down from Anchorage on the 28th of January, coldest it got was one night in Northway at -10F felt like Summer!

Merry Christmas and throw a snowball for me!

Tim

don d

12-25-2002, 10:33 AM

Jerry reffers to 400lbs. of ballast. Does that mean that each plane in the contest is ballasted to be carrying 400lbs. of load??? 150 lb. pilot and 250 lb. of ballast=400lbs.???

If that's the case my 275lb. carcass could compete.

Don

Dave Calkins

12-25-2002, 11:17 AM

I took care of 3 Beavers and 2 U-206's for an operator who had a very "thick" pilot working for him for several years.

The operator had an agreement with a certain lodge and did most of their flying work.

The German lodge owner was dismayed when he first saw the "large" pilot.

He exclaimed: "...Oohh, he ist three fishboxes...".

You can't take the big man out of the a/c if he happens to be the pilot. As always, the pilot reduces the payload.

Dave Calkins.

Jerry Burr

12-25-2002, 11:25 AM

In the Super Bush Challenge Match, the 400lbs (gravel or bird shot, depends on if you were first or last in line) is correct sir. You ran light on Saturday and the top 4 airplanes were then qualified for the last event on Sunday which was with the weight. Supposed to equal a quarter of Moose, or something like that. You would have to think thin on Sat. I lost 17 lbs for the event one year. And I only weigh 155. :) Jerry.

Jerry Burr

12-25-2002, 11:34 AM

Hi Don D. Sorry I misread your statement. The weight is IN ADDITION to everything else. It was the only time I took my CUB belt buckle off. Jerry.

don d

12-25-2002, 08:56 PM

This contest isn't fair. I"m 275 naked.(that's not fair either) Tall for my size but still not a pretty sight. My cub wieghts 1125 with it's jato (isn't that what they call those rockets on the back) and droop everything except my belly. I'm 276 with just my belt on. 2 quarts of oil = 15. 3 gal fuel= 18 and the 400 ballast just to make it fair and uhhhhhh++++= 1834lbs. Check my paper work and 1750 max take-off wieght. Damn, the Feds are over there. I have to stay home, can't play with you guys. :cry: :cry: Too bad, with the rocket power, it takes off backward and pulls the runway up behind it.

Don

I'm from Idaho and I'm kinda backward.

PA12driver

12-25-2002, 10:28 PM

Don D.

I am glad you are backward not Green, (be careful, you are not far from the Oregon boarder!)

Heck, My 12 is only legal to 1750 gross weight? I carry that much in the baggage department, Guess I am luckier then you guys cause the FAA has never been at the truck scales when I weigh the payload?

Does diesel really weigh less then avgas??

Tim

Jerry Burr

12-25-2002, 11:44 PM

Don D. Hey have you checked out sherpaworldwide.com? This one will carry you and your family and your inlaws, and still get off as short as a Cub. Check it out. Run it in the heavy touring class. You'd smoke em. Jerry.

Russ Kaye

12-26-2002, 03:20 PM

Hi Jerry,

I was reading one of your posts somewhere else on this site where you had mentioned That Byron Root had tried so many different modifications to the Cub wing and that led him into the Sherpa. It kind of got me wondering, has anyone tried movable slats kind of like the Courier only operated manually like with a flap type handle, pop em out on take off and landing and in for cruise, or is that getting too complicated and heavy?

PA12driver

12-26-2002, 06:46 PM

David C.

If you read this post, how about taking a picture of that PA12 with the Modifiedddddd Maule wing on it? I am sure that it had huge leading edge slats, spoilers, and flaperons? If we were talking about the same plane it was built in the Seventies and was an amazing performer, (can't for the life of me think of his name) he was killed in Bristol bay spotting fish? and used to work the winters as a page for the Legislature?

Tim

Jerry Burr

12-26-2002, 08:55 PM

RJK. The answer is yes and yes. It was done, it is heavy, and it is complicated. It was the Thompson Brothers Super Cubby. I can send you pictures of it if you want. Hi Tim. The name you are looking for is Sumner Puttman. It was a extended Maule wing on a PA-14 with a slat and lots of tricks. The slat that the Stolmaster is building is a spinoff of that idea. Jerry.

PA12driver

12-26-2002, 10:22 PM

Jerry, Now I know you do go back a ways with us (good ol boys) Sumner! He was a good wrench, if my memory serves me right he did have and aeronautical engineering degree, and loved to push the envelope. His workmanship was kinda crude, but the stuff he built did perform! He used to come over to my cabin when I could no longer land of the beach with my cub and he still had room to land and takeoff twice. Somewhere I must have a picture or two? I am pretty sure it started as a PA12?? David C. said he knows the guy that has the plane now? hope it is still flying?

Trust you had a good Christmas!

Tim

Dave Calkins

12-27-2002, 03:28 AM

Yeah, Sumner may have built more than one, Tim. And maybe it was a -14 that Jerry knows.

I just put fresh tailfeathers on the PA-12 based a/c with Maule wings and GIGANTO leading edge slats.

The thing's on 6" gear and 26" Bushwheels. I haven't seen it fly yet, but the owner says it'll fly slow, and he has no need for a PA-18. Says he hates the toebrakes.

Says he's landed this thing on skis in a snowed over alder patch and as soon as he was taxiing slow all the snow settled and he was sunk...in snow AND trees. FUN!!!!

Dave Calkins.

Gary Reeves

12-27-2002, 09:30 AM

Slots, slats, slits, grooves, fences and VGs usually will work on something that is not designed well. They will make a poor performer function, but seldom make a good performer better.

You never ever get something for nothing. Most of the devices are single design point fixes and do what they are intended to only over a small range of operation. If you want to take off and land really short expect to do it with your nose real high. Also expect your cruise speed to decrease.
The span wise location of slots and slats change the stall onset and speed of propagation of the stall along the wing resulting in very different flying characteristics. Look what Stinson went through trying to get something that would shorten the take off roll and landing speed and still be stable.
(I'd kinda like to see the recommended location for the Microaerodynamics VG STC on the 108 slotted wing).

If you want to modify your cub to be a short field winner, don't expect it to fly like it did before. It won't take long figure out what you gave up.

The only "high lift device" that I would put on a SC is a set of vortex generators. Then use the lower stall speed for margin and really appreciate that you have aileron control right down to stall. Still, you will loose some speed at cruise.

Gary

Jerry Burr

12-27-2002, 11:20 AM

Hi Gary. I'm sure you have heard the saying. "Say nothing about a person untill you have walked a mile in their shoes". The same goes for airplanes. It's obvious by what you say that you have never flown a slat. If you have an open mind and are willing to travel I can get you into one for a test flight. Just contact me. If the Stinson you are refering to was military, they had problems that I won't get into here. They weren't all aerodynamic. This is a great country and we all have the right to say what we feel, wether based on fact or not. I will agree that everything that flies is a compromise. None are perfect for everyone. My Cub goes higher, farther, faster, slower than it did when it was stock. If stock is for you, I have no problem with that. I have always said! "If you don't need a mod don't do it." :) Jerry.

Gary Reeves

12-27-2002, 12:20 PM

Jerry,

Yes and no. I have flown slats, but not on a cub. I have seen a set go on and off a local cub used in severe bush conditions.

What I have done is designed and researched high lift devices as part of my job for over 30 years (including slats). I am fairly aware of what happens to the Cp distribution with chord at various angles of attack and the associated increase in the loss characteristics.

If your aircraft (or any cub) has all the performance gain you mention, I an interested in understanding how and why. Unfortunately flying one won't do it for me. Changing conditions and lack of accruate sensitivity in the seat of my pants without a lot of before and after attempts usually leaves me scratching my head - or the seat of my pants. Do you have data? How much higher, faster, slower. what change in fuel burn. I'm interested.

Professionally I was never fond of VGs either, but, like you with the slats,
they feel good on the SC.

Gary

StewartB

12-27-2002, 12:27 PM

If you don't think slats work, you must have never been in a Helio.

Jerry, a friend of mine is working on a cub wing with self-deploying (Helio style) slats. Do you think there is any merit to the experiment? Might they work?
SB

Gary Reeves

12-27-2002, 01:27 PM

Never said that they don't work, I said that you don't get something for nothing. Additional drag comes along with the extra lift. That is the idea behind an aerodynamically actuated leading edge slat. At high aoa the pressure distrubution pops the slat out which redistrubutes the pressure loading and delays separation. . At higher speed it stows to avoid the resulting losses and drag. High lift devices cause higher drag. You either slow down, add power or tuck it back in.

Just because something works well - or allows a design to function- on one application, does not mean that it will have the same effect on everything. It would be like assuming that we all should put golf ball dimples in our surfaces.

GR

Just because they work on something that needs

diggler

12-27-2002, 02:37 PM

delete

Clay Hammond

12-27-2002, 03:28 PM

well put

Jerry Burr

12-27-2002, 05:33 PM

Hi Gary. I agree with most of what you say. I understand it better when you restated it. I couldn't agree more with the seat of the pants vs data. The Micro V.G. is the only thing that as far as I am concerned absolutely enlarges the envelope and does not slide it. It has been tested and retested. They reside in a dead area while in cruise. No so of the BLR. The Stolmaster slat is designed to have the advantages of the Helio type slat without the weight. And not the drag of a fixed slat. I'll send a PM. Hey Dave, we both may be correct. It seems the PA-14 was damaged quite badly and the wings may have been put on a PA-12 fuse. Have you seen 8500W in your turf? Jerry

Gary Reeves

12-27-2002, 06:04 PM

Portagecreek, obviously you dont know who Jerry Burr is.
--------------------------------------------------------------------------------

well put
_________________
Bury powerlines, not pilots!

Good point. I will take it off line since I am interested in understanding just what I need during the spring and fall to get out of the mud faster.

Apparently, I offended some folks. It was not intentional.

Gary

cubdrvr

12-27-2002, 06:12 PM

Gary...........I don't think it's possible to offend anyone on this site........lots of alligator hide here.........but a tuff crowd if ya slip up a little.

SuperCub MD

12-27-2002, 06:53 PM

I don't think anyone is offended to much, and if they can't take it screw 'em.

If we are going to get opinionated and offensive -
I've never seen a decrease in cruise speed with micro's, but maybe those BLR's do, because they are waaay up on the wing. But if you can afford the fancy BLR's, you probably can afford the extra gas and time it takes to get somewhere.

diggler

12-27-2002, 07:38 PM

delete

PA12driver

12-27-2002, 08:52 PM

Portage Creek?

Diggler and I are the current kings of offense/defense and no tact! So you will most likely fit right into this crowd. I must say that there has been a tremedous amount of Good info on this site, and some times it takes a little to stir folks into action?

Your comments don't worry me, it's the "Lake Clark National Park" address? That doesn't make you a tree hugger does it? I hate them darn parks, As far as I am concerned it is Still Mt. McKinley--and I will land any darn place I want, besides the best sheep hunting is in the park! What side of the creek is the boundary on anyway?

Ok enough is enough about Parks! The VG's are the best bang for the buck on a Cub Wing period, second only to "Lighten the load".

Continue the dialog please!!

Tim

Gary Reeves

12-27-2002, 09:18 PM

Lake Clark National Park

The park lives outside the park in Port Alsworth. The park boundary is at "Portagecreek'. Jay Hammond lives about 10 miles away. Some time ago a rival called Jay a "posey sniffing swine" and the marine. master guide took it in jest. I'll take your tree hugger question that way too.

I do get a bit concerned about how close the cub gets to hugging trees; hence, the interest in short take off capability. As far as I know only two of us really live in the park and my neighbor Howard and I would be glad to welcome you to Portagecreek. If you fly Lake Clark Pass and start down the lake from the sandbar you will see a horseshoe shaped island. To the shore side you will see a red on white Super Cub and an Orange on Orange Stinson 108 usually on floats.

We might know a few places for sheep or caribou or moose or a place to spend the night

Gary.

Gary Reeves

12-27-2002, 09:21 PM

Gary Reeves

12-27-2002, 09:22 PM

Gary Reeves

12-27-2002, 09:26 PM

Lake Clark National Park

The park lives outside the park in Port Alsworth. The park boundary is at "Portagecreek'. Jay Hammond lives about 10 miles away. Some time ago a rival called Jay a "posey sniffing swine" and the marine. master guide took it in jest. I'll take your tree hugger question that way too.

I do get a bit concerned about how close the cub gets to hugging trees; hence, the interest in short take off capability. As far as I know only two of us really live in the park and my neighbor Howard and I would be glad to welcome you to Portagecreek. If you fly Lake Clark Pass and start down the lake from the sandbar you will see a horseshoe shaped island. To the shore side you will see a red on white Super Cub and an Orange on Orange Stinson 108 usually on floats. We both have VGs, but Howard's tips droop and you might find dimple tape in a few places.

We might know a few places for sheep or caribou or moose or a place to spend the night

Gary.

Gary Reeves

12-27-2002, 09:28 PM

Lake Clark National Park

The park lives outside the park in Port Alsworth. The park boundary is at "Portagecreek'. Jay Hammond lives about 10 miles away. Some time ago a rival called Jay a "posey sniffing swine" and the marine. master guide took it in jest. I'll take your tree hugger question that way too.

I do get a bit concerned about how close the cub gets to hugging trees; hence, the interest in short take off capability. As far as I know only two of us really live in the park and my neighbor Howard and I would be glad to welcome you to Portagecreek. If you fly Lake Clark Pass and start down the lake from the sandbar you will see a horseshoe shaped island. To the shore side you will see a red on white Super Cub and an Orange on Orange Stinson 108 usually on floats. We both have VGs, but Howard's tips droop and you might find dimple tape in a few places.

We might know a few places for sheep or caribou or moose or a place to spend the night

Gary.

PA12driver

12-27-2002, 09:33 PM

Gary,

I think I remember exactly where you are! I used to spend a lot of time with Glen and Bee, usually helped dig potatoes in the fall on the way through hunting down south! Definetly a piece of heaven! For those of us that lived in Alaska before Statehood and watched the overtake of Parkservice, Forrest Service, and every other special interest (including) oil and gas development, it is a little hard to get used to not being able to go back to the land we used to stomp! I have a lot of respect for Jay Hammond, however I don't align mysef with most of his (current positions on Govt.) I must say he has done well for himself and accomplished most all he has set out to do! If I get by your way this summer I will stop in and visit (keep a look out for the "fat red cub".

Tim

Gary Reeves

12-27-2002, 09:45 PM

If you dug potatoes with Glen you are my kinda guy. He and his operation are still there. Jay does not fly now. Stop in. We monitor 122.9 the local CATF and 127.75 Glen's company.

Gary

PA12driver

12-27-2002, 10:16 PM

Portage Creek,

Nothing better then Bee's cooking at the "farm". spent many days with the cub hunkered down beside the hanger, and helping keep the beaver, cubs and what not from pounding themselves to pieces in the cove! I have heard that it is getting pretty developed by the "big strip" and alot of other cabins around, haven't been there in about 10 years!

Used to spend a lot of time down fishing on the Gibraltor River, and hunting on the Peninsula.

Tim

Dave Calkins

12-28-2002, 02:09 PM

Hi guys. Hi gals.

I'll try not to sound like an idiot here, so Digg won't confuse me with our president, who's a lot better thinker, and hirer of thinkers, than he is a showman. (yes, Diggler, I've left that one wide open so you can have a little fun with your next post and comments).

Portage Cr. Gary, and Tim R., former gov. Hammond is still a popular guy here in the city, even with the conservatives, because he still makes sense with what he says, even though we don't agree with what he says. I guess in the bush he's still adored because he designed a way to give free money to every Alaskan citizen. That's real cash for people in the bush that may have no other means of obtaining real cash.

My problem is that he supported, this last election, a candidate who I believe would have thwarted our abilities to utilize resources that we MUST have access to. 'Nuff said.

Back to the VG's. The BLR set-up on the PA-14 slows cruise about 1 MPH.

I'll take that trade-off any day. Big tires will cost you far more speed than that, but their importance is worth the speed. Same as the VG's are worth it.

Portage Cr. Gary, I agree with your original comment of using the lower stall speed created by VG's as a "margin" and appreciating the improved low-speed aileron authority the VG's afford you.

I'm not so sure I agree with you that sacrificing a Cub's cruise speed for some better ultra-low speed flying is sacreligious. We're talking about an airplane that will do a good 89 MPH if it's lucky, and the tires aren't big.

That's my opinion.

OK Diggler, I'm waiting for your punches.

Tim, heard from Crash in awhile. I don't think I've seen him post lately?

Dave Calkins.

PS Mr. Hammond got a ride to his place a couple weeks ago from Katmai Air. I was at their hangar building-up coats on some tailfeathers at the time. He still looks healthy, sorry he isn't still doing his own flying.

PA12driver

12-28-2002, 02:35 PM

David,

I to admired JH for what he did to "share the wealth" to the "locals" especially those that chose to live in the "Bush". What confuses me is how he now seems to cowtow with whom ever will pay for his services? I guess that is what makes up a Politician? Isn't that in opposition to everything that he said he stood for when in State Office?? I must admit that I have been away from Alaskan polotics for over 12 years so I don't claim to be accurate on all issues, (I will leave that to you guys that still live there!

Sorry, This should not be the subject of this thread? (Steve-you can move it if you want??

Tim

About the VG's. I think the topic has been talked to death! Those that have them like the improvement, those that don't have them and comment on them (should fly them and then comment?)

As for speed in a Cub??? Non Issue (come on even I can do the math--you don't save enough time by going 1-2-3 miles an hour faster!

cubdrvr

12-28-2002, 05:06 PM

Lighten the load" is #1, and maybe you are right Tim when you say "most bang for the buck"on the VG's but notwithstanding the cost I would put the Borer prop at #2 and VG's #3. I put the Micro's on during rebuild a couple years ago........never flew with them previously......and have to say that I am quite impressed. Not counting bigger engines, flaps, slats, or pilot technique what else would enhance performance on the cub?

S2D

12-28-2002, 05:33 PM

Probably getting into a gray area here but what about washout? If you took half of the washout out of the wing you should get better lift, but what about overall performance?

12-28-2002, 05:36 PM

cubdrvr,

I would agree with you as to the order. The challenge still remains that as someone has already said----it is very hard to talk about performance of a cub due to the fact that "most" have been modified in some fashion or the other since coming out of the factory.

One has to determine the intended use and then make modifications to suit that use?

An example is Jerry Burrs white hawk will definetly out perform in take off and landing "When operated at "competition weight", compared to a stock cub, or a fat 12 like mine! I think Jerry would agree that if the wind was blowing 30-35 like the day we were down here last summer, he is at a disadvantage over even a stock cub when it comes to getting the bird to roost!

For those of us the use our planes for recreational flying, camping, hunting and horsing around, (we) are going to have to settle on a compromise as to performance, and as well the depth of the pocket book is a determining factor.

Basic premis is still to add as much performance with least amount of weight gain.

1)-lighten up the Pilot-minimum mods to plane needed to provide added strength and dependability (tail brace, saftey cables, hd gear, best brakes, "soft tires" height/width to suit environment--precise rigging of airplane for best performance
2)pack the best quality lightweight tools, and survival gear
4)borer prop
5)-VG's of either manufacture
6)minimum fuel to make the trip safely
7)lightweight, minimal instrument panel, handheld GPS/radio
8) pilot technique and practice make the most difference-period!!

I would add that if a person could shoot for an empty weight of 1150 on a SC he would get adequate performance!

All the rest is personal preference and trial by error
90% of the fun of flying a cub is riding on the edge of its limits! and testing our own!

Tim

Dave Calkins

12-28-2002, 05:48 PM

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?

http://www.supercub.org/upload/12slat1.jpg
http://www.supercub.org/upload/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.

Mauleguy

12-28-2002, 06:43 PM

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

PA12driver

12-28-2002, 06:57 PM

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

Dave Calkins

12-29-2002, 12:43 AM

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.

cubdrvr

12-29-2002, 09:18 AM

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?

S2D

12-29-2002, 12:18 PM

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.

piperpa12

12-31-2002, 02:07 PM

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.

PA12driver

12-31-2002, 08:06 PM

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

Gary Reeves

01-01-2003, 09:18 AM

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

01-01-2003, 06:14 PM

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.

piperpa12

01-01-2003, 07:24 PM

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.

PA12driver

01-01-2003, 07:32 PM

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 ??

Steve Pierce

01-01-2003, 07:51 PM

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.

diggler

01-01-2003, 08:12 PM

Idelet

StewartB

01-01-2003, 11:55 PM

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

Dave Calkins

01-02-2003, 11:36 AM

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.

diggler

01-02-2003, 11:50 AM

delete

Dave Calkins

01-02-2003, 12:15 PM

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.

piperpa12

01-02-2003, 12:43 PM

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.

diggler

01-02-2003, 03:12 PM

delete?

diggler

01-02-2003, 03:47 PM

Idlete

piperpa12

01-02-2003, 04:16 PM

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.

Don

01-03-2003, 10:18 AM

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???

01-03-2003, 11:24 AM

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?

diggler

01-03-2003, 01:42 PM

delete

stolmaster

01-04-2003, 06:24 PM

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

Jerry Burr

01-04-2003, 07:20 PM

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:

PA12driver

01-07-2003, 12:46 AM

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

Dave Calkins

01-07-2003, 01:01 AM

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.

RedBaron

01-07-2003, 01:21 AM

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

Dave Calkins

01-07-2003, 04:21 AM

Somewhere on this site we had a discussion about the turbulence caused by the extra 3" of flaps extended INBOARD to the fuselage. 'Nuther 3 inches is what the thread was titled.

Back to the airfoileed, VG'ed, or enlargened tail:

I checked out the airfoiled tailfeather thread and didn't find an answer.

It seems like since we know we want "lift" on the tail in a certain direction (down, of course), we'd design an airfoil cross-section that would work FOR us. Or would we just get along with a stock symetrical "flat plate" of an airfoil, and mask the problems with the "magical" vortex generator??

Piper designing for simplicity, light weight, and low-cost aside, where are we on this issue??

Dave Calkins.

Gary Reeves

01-07-2003, 10:25 AM

Seems to me that someone (hint hint) working with slots and slats could take a look at turning the gap between the horizontal and the elevator into a slot shape that would close at full up and open on the way down . Both the change in angle of attack on the elevator and the coanda effect of the designed slot would at least unstall the elevator.

Gary

Russ Kaye

01-07-2003, 02:03 PM

Anybody know anything about the Riblett GAU 613-66" wing that D&E advertises? I e-mailed them to ask for some names of people that have bought them so I could find out how they worked but haven't received an answer.

Jerry Burr

01-07-2003, 04:11 PM

Hi Dave. When I was testing V.G.'s on the wing, it was clear that the wing efficiency was improved to the point that the tail (horizontal/elevator) no longer had the authority to stall the wing. The problem had to be corrected before further testing could proceed. I am currently using a PA-20/22 balanced tail. The fix according to Mr. Dodge, and a requirement on one of his STC's was to install the 6" longer PA-18 tail. I rejected this because of the additional weight and the increased twisting moment on the fuselage. Cost was also a factor. It was only logical that the V.G.'s caused the problem (with the wings) that they should be able to fix the problem (with the tail). I installed them under the horizontal and the problem went away. Later when the wing testing was complete, I revisited the tail and removed all of the V.G.'s that were not necessary, leaving only enough V.G.'s to completely stall the wing for 3 point landings. (with power). The weight of the additional V.G.'s was 1.6 oz. I believe that 95% of the stock engine/wing PA-18's will get along fine with a stock tail if flown using the techniques outlined in the { Landing Short Over A 50 Or 100 ft. Obstacle } thread. I don't believe that power off or ( 0-thrust ) landings have any place in the STOL world. In addition to giving the tail more authority on approach, using power makes it less likely that the engine will falter (fart) when a burst of power is needed for a power flare. For the other 5% or those with modified wings, the large squared tail with V.G.'s is about the limit for a practical application. An all flying tail (stableator ) is probably the best, but it and it's mounts are heavy. The real problem to deal with at high AOA is that the stabilizer acts like a Delta Fin and tends to push the tail up (you can see Delta Fins under the tail of the new Lears) as the elevator is trying to push it down. At some point they just cancell each other out. The easiest way to solve this is to reduce the size of the stabilizer. (( For those that have BLR kits and have installed the plates on the fuselage that effectively INCREASE the size of the stabilizer, please don't ask me for ways to increase the elevator effectiveness. You have created your own problem )). A simple/light method would to add an airfoil to the bottom leading edge of the elevator. A slat if you will. They were used on Polish built Storches. They would be simple to add to the existing structure. The inverted airfoil that some STOL types use, are hard to adapt to the Cub. They have to be both large and light and on a Cub STRONG. The Cub tube and fabric is about as sturdy and simple as you can get. If I had elevator problems, I would probably test the elevator slat first. Wayne is involved in this problem on his STOLMASTER Slat kit. And he will probably have a lot to add to my simple musings.

stolmaster

01-07-2003, 07:50 PM

Gary, Ok i'll take the bait. The slat on the tail has been used with good success. The
problem with it on a cub is draging your tail through the brush. I know we would'nt
this but fact is fact. Still it would be the best and simplest on a cub. Just got told
I have to leave. Will be back with what i a'm doing with this problem
Wayne

CubCouper

01-07-2003, 11:14 PM

How difficult would it be to test an inverted airfoil on the stab surface? Say, peel the fabric, and attach a thin rod (maybe 3/16 or so) across the ribs on the bottom side. This would create a slight airfoil shape once the fabric was shruck back on.

http://www.supercub.org/upload/CubCouper/mod_stab.gif

Wayne Mackey

01-08-2003, 12:53 AM

Gary, Remember 95% of the toys i make are installed on Exsperimental aircraft so testing isn't as much touble. I think i have come up with a way to clamp a slat on
18 tailfeathers with out damage to the fabric. We know it works but how much.
I have been using long flaps as well as drooping ailerons. With my slats we can
droop them about 23 degree's and keep fair control. We all know the wind can be
a problem here so i make my system so I can disengage the droop at any time in
flight. Anyhow I have a big pitch control poblem when the plane is in the light weight mode.
With the PA18 tail and the power on no problem, but with the power off keeping
the nose high is prettie tuff. My plan is to make a panal in both stabilizers that
comes up like the elevater. In doing so it will decrease the size of stabilizer and
increase the size of elevater. At high angles of atack or desent the stabilizer
counteracts elevater. This system will be controled by the flaps, more flaps more
up panal. What fun! Wayne

Cubcouper, In the mid 70s we made PA18 tail with an airfoil . We didn't gain enough
to be worth the trouble. Good luck , hope yours is better than ours.