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Performance STOL Double Slotted Flap system now STC'd for the PA-18

Doug built a Super Cub with Husky flaps many years ago. I sold him the flaps and hardware from a wrecked border patrol Husky I had. The Performance flaps must be better since he spent the time and money to certify them.
 
Re: comparing flaps of the same length?

My impression of the much longer Husky flaps was that they were not nearly as good as a stock set of Super Cub flaps adjusted to the max allowable extension. My guess would be that the more effective Cub flaps would be even better if Husky length. I think my opinion is worthy.

Next question: has anyone installed these STC flaps on a Dakota slotted wing?
 
The thing is that my wings are different than stock, my fault. I don't know how my "wing cove" would affect the performance of those flaps..??... First slot would not be the same

And why do you guys install flap gap seals???


Thanks!
 

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The Husky flaps are for sure longer, but far bigger slot in them when fully deployed compared to Keller flaps. The Keller/Airframes AK flaps are a bit deeper, extend a bit past trailing edge of wing than stock cub flaps, and have two slots. My view is they work well as they do extend further down than stock and Husky flaps, and have the two slots, probably giving some added lift with airflow going through two narrower slots rather than one big one. Not sure of aerodynamics there, but just my take.

Most guys flying Husky's pick the tail up like one does in a cub for takeoff run. Not needed in Husky as flaps are creating lift. Just stay three point, stick back and just levitate. Sometimes tailwheel is still last thing on the ground. Shortest way to get off in Husky.
Keller flaps are a bit similar, but I cannot tell much difference in raising tail in cub with them vs. not. Still levitates.
John
 
Most raise the tail on takeoff in all taildraggers. My experience is that doing so always results in a longer takeoff roll. It might be necessary in a few airplanes that lose aileron response at low speeds, but the only time I raise the tail is when the student is rudders only.

I remain unimpressed with the Husky, except for its cruising speed. A good Super Cub is much more fun to fly, flaps or no. Most Husky pilots in the lower 48 are taught to approach at 60. That works in a Cub, but in a Husky you will miss your turnoff if you come in over 55. I believe it is because of the flap extension restriction.
 
I have a cub with the Airframes/Keller flaps and 2 Husky's. Both Husky's are lighter weight than normal ones so perform better. One not quite finished yet, so actual weight unknown until next month, but should be well under 1200lbs. Other one is 1309lbs with 31" bushwheels and extended cub gear. Lycon built 0360 engines that dyno about 220HP.

One has to fly a Husky far differently than a cub. Cannot point it to the spot and land there like a cub. Have to slow it up under 50 on approach, in three point attitude and plop it down where you want it to go. As you say, too fast and you completely miss your spot. Key is slow flight and nose high to make the spot. I see most guys in lower 48 going way too fast, so no performance anywhere near cub. Cub will get in and out a bit shorter for sure, but not by much compared to my Husky's.
I personally like flying the Husky better as they are more comfortable, a bit roomier and more solid to me. And of course with constant speed better rpms and less vibration. And Husky is far faster.
Like the cub and Husky, have both, they just fly and have to be flown differently.
John
 
So keep the tail up when you don't want to leave the "runway" (so you don't bounce off it sideways before ready to fly in the gusts and bumps) Then put the tail down when you're are ready to fly. The rest of the "how to" is moot if you're not in a restricted space or gusty crosswinds.. do it anyway you like. Also, if you are in a very restricted space, leave it on the ground until the last of the runway. That way, if you stand a chance at all, it will work. .... soft fields notwithstanding.. them.. be like on floats.. lift one a little bit.. let it accelerate to the very end.. then try it..or crash, but don't try to take off early on a short field.
Usually if you keep it on the surface it will fly without any extra help before the end unless you seriously made a mistake. If you try to fly too early you might cause it to go off the end..
 
if you are in a very restricted space, leave it on the ground until the last of the runway.
Yeah, sure beat the hell out of your tail if you like but lifting the tail is not going to hurt your take off if you know what your doing.

I like to see where I am going in a very restricted space. If you are on 35" Bushwheels the visibility over the nose is nil. Lift the tail and everything is laid out before you...
I am use to flying in and out of 300 feet or less with maybe 10 feet or less of margin either wing tip, I am probably light so I will lift the tail every time.

That is the beautiful thing about the cub is the tail is light and you can lift it, it is a lot harder to do with other aircraft and that is the thing I usually hate the most!
 
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If I need my shortest takeoff the thing that makes it happen is the flap lever, and if I'm pulling flaps to get off quick I need to have the tail up so I have full authority of the elevator in a relatively flat attitude. If I want to use every inch I delay pulling on the lever until I have to, and at that point I've maximized my speed in the available space.
 
Look at the Rev 3 flaps. Simpler and lighter. Performance reports are good. A guy could fab those easier than split flaps. Big chord, big span, and ducted leading edges. I'm looking forward to seeing more of them flying.

Stewart, are there any more pictures besides the one in the Daydreaming about Flaps thread? I'm really curious to see where the ducting outlet is.

Vic
 
Yeah, sure beat the hell out of your tail if you like but lifting the tail is not going to hurt your take off if you know what your doing.

I like to see where I am going in a very restricted space. If you are on 35" Bushwheels the visibility over the nose is nil. Lift the tail and everything is laid out before you...
I am use to flying in and out of 300 feet or less with maybe 10 feet or less of margin either wing tip, I am probably light so I will lift the tail every time.

That is the beautiful thing about the cub is the tail is light and you can lift it, it is a lot harder to do with other aircraft and that is the thing I usually hate the most!

I was talking about the airplane itself when I referred to leaving "it" on the runway.
Not the tailwheel.
Apologies for any confusion.
Mauleguy, happy for you and your small area accomplishments. My work plane has good vis over the nose but I don't seek out tight spots. I only let my tailwheel touch the ground when I have to.
Stewart has it right in his statement about waiting until he has to make his best move. That was my point.
Have fun and all the best.
 
I'm in the process of installing the slotted flaps from Airframes Alaska. The slotted flaps are a bit heavier than the ones I built from the D&E kit. There were a number of problems because I had built flap and aileron hangers of my own design to accommodate the D&E flaps and ailerons, but I have worked out all of the problems but one. The flaps are too heavy for the flap return springs. The flaps will not fully retract. The springs that I am using I procured from Univair, so I'm looking for a solution. Stronger springs would be the obvious way to go, but I don't know where to get them and I don't feel like having them made at the local spring shop.

Any suggestions, anyone?
 
You can try the Univair heavy duty flap springs but I've heard guys have had them break with PStol flaps. My flaps are longer than yours and I use four of these on each flap. Two on a yoke and cable to each bell crank. They work well.

https://www.mcmaster.com/9654k331IMG_4798.JPG
 

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I'm in the process of installing the slotted flaps from Airframes Alaska. The slotted flaps are a bit heavier than the ones I built from the D&E kit. There were a number of problems because I had built flap and aileron hangers of my own design to accommodate the D&E flaps and ailerons, but I have worked out all of the problems but one. The flaps are too heavy for the flap return springs. The flaps will not fully retract. The springs that I am using I procured from Univair, so I'm looking for a solution. Stronger springs would be the obvious way to go, but I don't know where to get them and I don't feel like having them made at the local spring shop.

Any suggestions, anyone?

how many springs per side do you have?, I usually put 2 per side just use longer bolt in bell crank, and add another outboard tab on spar....

but I have not done a split flap install on STC cub ones yet...
 
I can't tell from the picture, but it looks like you made a yoke and cable in place of the long wire that comes off of the stock spring. Good idea.
 
I got this setup from Backcountry Cubs. Basically it's like a little block and tackle. You have the full strength of the spring holding the flaps up. But because of the two pulleys, the springs only streach about 1/2 their length with the flaps fully extended.

I'm still building my plane, but in the shop it works nice. My only complaint is the cable clearances are tight. I had to add a small pulley to an alieron cable so it would clear.
008815a3e7bc461fd57744446bb6d18c.jpg


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Rev 2 or 3? That's VERY different from my Rev 2. Probably in response to how a few Rev 2 builders were struggling with flap droop and cable tension. Do you have a pic of your flap bell cranks? I'd like to see if that changed, too. How much flap angle are you targeting?
 
Rev. 0. [emoji16]
I got the fuselage and wings from Nick Smith before he sold the company to Backcountry Cubs. It's my retirement project and I recently retired.
The wings look to me like PA-12 based. I would guess the bellcrank to be stock.
I bought the spring setup straight from BC Cubs a couple of months ago. I assume it's their latest and greatest.

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I believe Dakota Cub makes a stronger spring, not sure of that - correct me if I am wrong. Mine will sometimes blow down a little when taxiing downwind or at the fuel pump. But I would have to cut an access hole in the wing to change it out and they might be harder to pull with the short flap handle.
 
But I would have to cut an access hole in the wing to change it out and they might be harder to pull with the short flap handle.

alway's plan on needing to replace flap springs when covering... add an inspection rectangle.... you can contact cement one on now and cut it out.. I like 3m Fastbond 10 contact cement
 
I got this setup from Backcountry Cubs. Basically it's like a little block and tackle. You have the full strength of the spring holding the flaps up. But because of the two pulleys, the springs only streach about 1/2 their length with the flaps fully extended.

I'm still building my plane, but in the shop it works nice. My only complaint is the cable clearances are tight. I had to add a small pulley to an alieron cable so it would clear.

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Very cool design. Unfortunately, That would require cutting a lot more fabric that I want to do. Thanks for showing it. Things do get tight behind the rear spar.
 
I added a simple external retract spring which helped a lot.
 

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