The Wag-Aero Sport Trainer - Differences from the real PA-11

[RAVC1]

My son has been a SC fan for several months. I intend to purchase him a set of the Sport Trainer plans and we will build it together as a family project. I read here that it is known to differ from the true PA-18 but the distinctions were not listed and I do not follow the SC. Can someone hep me with understanding the differences? We'll want to build it light and set him up with flaps and 29" or 31" so I appreciate any direction you can offer.

Rick

 

[Colorado-Cub]

The Sport Trainer ("Cubby") is essentially a J3. Some Cubby kits are a full wood wing (spars, ribs, and all), the wing plans call for a slightly different leading edge profile (slightly more round like the Husky). The fuselage has plans to allow it to support the weight of heavier motors than intended to mount on the J3. The tail feathers of the J3/Cubby are slightly smaller than the 18; the rudder has a slightly less round shape and is more J3 like, and the and the plans depict unbalanced elevators.

PA18 wings will not simply bolt up; the front wing spars carry through to the center of the airplane just like a J3, and I have never seen flap plans provided by Wag Aero for the Cubby (although they would be easy to extrapolate).

The good news is that landing gear, float gear fittings, and tail post fittings are all identical to PA18/11/J3. I have PA18 elevators, PA18 ABI +3 extended gear, 29" bushwheels with Acme suspension front and rear, and a Javron zero thrustline PA18 mount on my Cubby without modifications.

The Cubby is a great value, and a decent stand-in for an experimental PA-11. It is a small, cramped, loud, slow, and absolutely wonderful flying airplane. I adore mine.

If you have any specific questions about the plans, I have some here and can take some area specific photos for you if you like.

 

[Colorado-Cub]

...forgot to add:

Don't let the lack of flaps deter you. The real limiting factor when bush-ready (heavy) is being getting out of what you were able to easily get into. I can get into places way shorter than I can get back out of, even if those places are slightly longer than what a real 18 can accomplish with the same pilot.

If you want something to haul a load or get somewhere fast, let those two factors deter you.

 

[RAVC1]

Colorado-Cub,

Thanks for your response. I guess I made my ignorance of the Cub product line formal! How close the the PA-11 can the Cubby/Sport Trainer become? Speed is not the issue; my son understands this. The short-field performance is the goal but I do not know how well it's inability to carry a load will go over with him. I can only pass the information you provided on to him. I'll show him the Wikipedia page for the PA-11 to get him started in considering this. What engine choices are possible? Can you attach a couple of photos of yours to another response?

I know Christian Sturm built a PA-18 from scratch. Are people doing this from the SWPC drawing CD's? I intend to purchase these as references anyway so they will be here.

 

[Colorado-Cub]

The most beautiful thing about experimental aviation is that the sky is not the limit. Unfortunately, there are so many possible choices you can spin yourself in circles trying to decide what to build...

The Sport Trainer can be as close to a clone of a PA-11 as you want to make it, however the plans differ slightly across the entire airplane to a real 11 in very nuanced ways. Most everything is so dimensionally close to a J3/PA11 that you can scrounge parts relatively easily. Dual wing tanks and C90 and it is a really good performer, and in many ways it could be slightly better than a real 11 however I admit I am biased; I prefer experimental to certified. Drop the starter and the electrical system, run a composite prop and this airplane really shines. Unfortunately those are some creature comforts not everyone wants to give up so there is always a balance between brute utilitarianism and practicality. The great thing is that you get to decide what is best for you and your mission. For instance, I have a a lightweight electrical system to power my full Dynon glass dash with ADSB out, but no starter simply because that is what floats my boat.

There are many Sport Trainers running C90s all the way up to O320 Lycomings, clipped-wings through extended wings. I have an O235 Lycoming on mine and it is the worst of all worlds; it is both underpowered and very heavy. Two-up with half fuel at my normal DAs of 8K+ and mine is a real dog. If you are closer to sea level you would be happier with the performance and can get away with a smaller+lighter motor.

Cubby's often can't be differentiated from a J3 or a PA11 just by looking at one, so don't feel bad. There are a few tell tale things that stand out on the Wag that you will learn to recognize after comparing a few real Piper's to a Wag. It is important to at least offer that Wag Aero has never had a great reputation for quality control, so if you ever purchase parts from them be mindful you may spend some extra time getting them air worthy for install. I bolted many Univair parts on my airplane at a greater expense but with a greater confidence of initial installation. Your mileage may vary.



The Northland plans with the L21 additions is a fantastic resource. I bought mine from this very site on a USB stick, and you should absolutely get those if you have not already.

 

[Colorado-Cub]

Although not quite SQ2 capable (red and yellow is a drool-worthy SQ2), this little red Cubby holds its own out the Utah paradise lands:



Here is a real J3 next to the Wag:



From the air the only thing that gives away my Wag not being certified is the sky light:



If you go down the road of building with wood, I can share some tips that may speed things up. (I like wood and mine is a full wood wing):

 

[cubdriver2]

CC, looks like you added what I think is most important is the adjustable stabilizer

Glenn

 

[RAVC1]

Colorado-Cub,

I gotta say...love the dog! Great companions! I forgot I found one of these Cubby's for sale on hanagar67 this weekend to see what they looked like in comparison to the Piper. I showed the ad to my son but I guess we were both fooled regarding what it was. Nonetheless, these are beautiful aircraft. Is it 3-seats? The rear bench appears fairly wide. What size tires is yours equipped with.

The big point is my son wants the 'on-axis' flight position. I have always been under the impression that a wood wing is lighter but I do not know this to be fact. Wood is certainly easier to work with when you have fewer tools. The sunlight is the only way to go! I know of Wayne Mackey and his reputation. He has done excellent work but I prefer the P-STOL flaps. However, this is a good reminder for me to show my son Wayne's efforts so he can make an informed decision. I the experimental category too. I'm trying to determine something a little larger my wife and I can get into which might also hold all three of us or have room for four.

What is the benefit if the adjustable stab? I only have a working knowledge of these.

 

[Dan Gervae]

I built one up as a PA11 with an O200…I have the trim tab instead of the Piper style adjustable stabilizer. I think it work fine…I have also owned a J3 since 1991 so I do know the difference. I put an electric servo on my trim tab…it works good, I don’t haul heavy loads at wide range of cg….if I did I’d wish for the adjustable stabilizer for sure. I do have theabilty to shim my stabilizer by removing 2 nylock nuts. If I started over I probably would do the jack screw. You are probably further ahead king the 18 upper deck as well. It’s a lot of work to plans build a plane so be prepared. Many parts can be purchased but they are not cheap. Again, Be prepared. unless you buy a kit, you’ll invest possibly 2000-2500 hrs depending how much fabrication you do and your skill level. Mine is a big step up in comfort from my J3….I really love it.

 

[Colorado-Cub]

CC, looks like you added what I think is most important is the adjustable stabilizer

Glenn

I really prefer the jack screw over the trim tab, but that again is just a personal preference mostly because it works better with my gurney flaps.

 

[Colorado-Cub]

I built one up as a PA11 with an O200…I have the trim tab instead of the Piper style adjustable stabilizer. I think it work fine…I have also owned a J3 since 1991 so I do know the difference. I put an electric servo on my trim tab…it works good, I don’t haul heavy loads at wide range of cg….if I did I’d wish for the adjustable stabilizer for sure. I do have theabilty to shim my stabilizer by removing 2 nylock nuts. If I started over I probably would do the jack screw. You are probably further ahead king the 18 upper deck as well. It’s a lot of work to plans build a plane so be prepared. Many parts can be purchased but they are not cheap. Again, Be prepared. unless you buy a kit, you’ll invest possibly 2000-2500 hrs depending how much fabrication you do and your skill level. Mine is a big step up in comfort from my J3….I really love it.

Anyone thinking about building an 11 should read Dan's build log. Top notch workmanship that created one heck of a nice experimental 11. (Great job Dan)

 

[RAVC1]

Better idea...drop in during a fly fishing rip to the UP later this year...oops! Sorry for that Dan. I'll certainly look up his build log. All of this will help my son in furthering his study skills.


Edit - Dan, could you provide me with the build log for your PA-11. I tried to locate here under this same forum but there are an excessive number of pages involved.

 

[cubdriver2]

I really prefer the jack screw over the trim tab, but that again is just a personal preference mostly because it works better with my gurney flaps.

Pictures?

Glenn

 

[Colorado-Cub]

Pictures?

Glenn

Of the Gurney's?

 

[Farmer Hank]

I finished a Sport Trainer in 1986. PA-18 overhead, wood wings, balanced elevators, jack screw, 0-320, standard SC flaps and ailerons. Cruise 104 mph. I am now replacing the wood wings with aluminum spars and ribs, 90-inch flaps and ailerons, and a number of upgrades discussed at length on this site. Thanks to all of you! If you have read this so far, here is some good news: I will give away a couple of boxes of steel wing hardware to a good home. (Made from the Wag-Aero plans.) Also four 16-gallon wing tanks which proved to be much more range than I really needed. (Back to two 18-gallon tanks which a friend gave to me!)

 

[RAVC1]

I'd love to take these items off your hands but I suspect shipping will prevent this.

 

[cubdriver2]

Of the Gurney's?

Yup

 

[Bill Rusk]

Just to make sure that we are all on the same page, the sport club (cubby) is not a super cub. If you want to haul a load, take the airplane camping, trips to Alaska and Canada, and things like that I think you will be disappointed. In general it is a wonderful airplane for the local area, and they are a ball to fly, I just want to make sure you know that you are not getting a load hauling supercub. Those plans are available on the Northland CD which is sold here on supercub.org.
If you want a lightweight airplane that is fun to mess around in the local area, it’s tough to beat a J3 or PA 11.

Hope this helps


Bill

 

[Colorado-Cub]

Yup

I don't have any great photos, but here are a few randoms,

Here are prototypes made in aluminum to figure out how big/deep I like them. I ended up liking 1" deep test parts the best:



I drew up a quick idea of what the mold for carbon could be:



Pulled some test parts out of a quick wood mold in fiberglass:



I learned how much it would cost me to mold them in carbon fiber, then quickly decided to stick with fiberglass. Sanded and painted:



Looking back under the wing in flight The gurney is not actually warping; it is just the lens in this photo. (look close, that is a J3 down on that there beach):



As viewed from the front (while frolicking in a flower patch):



Gurney's changed every aspect of my flight envelope, mostly in good ways but in a few bad ways as well. The most confusing part is that I need almost full nose-down trim of the jack screw during cruise. If you think about that for a minute, it really should be the other way around considering a flap causes a nose down pitch, not a nose up. But, alas, the jack screw trim can handle it just fine and I have grown to love the idiosyncrasies of the gurneys. They absolutely shaved 5+MPH off the landing speeds and make ridge soaring in a chubby-cubby way more fun even if they whacked my cruise speeds.

Sorry for the thread drift.

 

[Farmer Hank]

 

[RAVC1]

Bill,

Yes. I learned that through this thread. I also changed the title to 'PA-11' from my initial PA-18 to make the title more appropriate for the subject matter.

I had time to talk with my son about the PA-11 and he did not like the load carrying capability so it appears I have not made much progress.

Just to make sure that we are all on the same page, the sport club (cubby) is not a super cub. If you want to haul a load, take the airplane camping, trips to Alaska and Canada, and things like that I think you will be disappointed. In general it is a wonderful airplane for the local area, and they are a ball to fly, I just want to make sure you know that you are not getting a load hauling supercub. Those plans are available on the Northland CD which is sold here on supercub.org.
If you want a lightweight airplane that is fun to mess around in the local area, it’s tough to beat a J3 or PA 11.

Hope this helps


Bill

 

[bob turner]

I have no connection to the Legend Cub folks, but seems to me they sell kits, with a lot of the more popular features - wider cockpit, PA-18 wing attach, choice of engines - worth checking in to?

 

[Cub Builder]

My son has been a SC fan for several months. I intend to purchase him a set of the Sport Trainer plans and we will build it together as a family project. I read here that it is known to differ from the true PA-18 but the distinctions were not listed and I do not follow the SC. Can someone hep me with understanding the differences? We'll want to build it light and set him up with flaps and 29" or 31" so I appreciate any direction you can offer.

Rick

The Wag Aero plans can be used more as a general guideline and you can build it any way you wish. I bought mine unfinished from an estate after the builder passed away. Most of the odd mods done to my plane were done before I bought the project, but I chose to keep them as I moved on to completion. My wings are all wood, but configured to mount the same as a SuperCub. The front interior structure strongly resembles that of a Citabria more than a Cub, although the interior space is Cub sized. The wings are also extended, with the ailerons moved 18" outboard and extra wide flaps. I chose to use the trim tab rather than the Jack screw. Lots of people love the jack screw. All I can say on that matter is the trim tab configured with a Ray Allen trim servo works really well for my purposes. If you build with a trim tab, don't build it with the bowden cable for trim control as you get flutter when the cable fails. I had planned to use an O-235-L2C bumped up to 125HP, but ran across a wrecked O-320-E2G at the right time and bumped it to 160HP when I overhauled it. With the long wings, the plane is heavy handed, but also incredibly stable. With the O-320 on the front and long wings, it worked exceptionally well for me when my home airport was at 7000'. Now that I live near sea level, I would probably prefer the non-extended wings. The point is, you can build it to be anything you want once you look beyond the Cuby plans. There are lots of plans and ideas out there. You can borrow from any of them and incorporate the ideas you like into your build.

-Cub Builder

 

[Colorado-Cub]

Long wings, flaps, and a O320 is all I would want for Christmas. I am green with envy.

 

[pilotski]

My son has been a SC fan for several months. I intend to purchase him a set of the Sport Trainer plans and we will build it together as a family project. I read here that it is known to differ from the true PA-18 but the distinctions were not listed and I do not follow the SC. Can someone hep me with understanding the differences? We'll want to build it light and set him up with flaps and 29" or 31" so I appreciate any direction you can offer.

Rick

I have a set of home built wings

 

[BC12D-4-85]

Later Gurney flap design includes a serrated design. See the applications here under STOL: https://aeroacoustics.com/files/products.htm Some Cessna Caravans have them here. The serrations form small vortices behind the wing which allegedly delays airflow separation in that area and can reduce drag. Back to topic.

Gary

 

[Colorado-Cub]

Later Gurney flap design includes a serrated design. See the applications here under STOL: https://aeroacoustics.com/files/products.htm Some Cessna Caravans have them here. The serrations form small vortices behind the wing which allegedly delays airflow separation in that area and can reduce drag. Back to topic.

Gary

Holy cow. That is a great idea since the VG is built right into the mini-flap. Thank you so much for posting that, I will have to build a set and see if they work any better for me.

 

[pilotski]

I also see a set of home built wood wag aero wing in the classifeds under parts and peaces

 

[Farmboy]

Just to throw this out, if you are considering a light yet capable experimental take a look at what the Bearhawk LSA does with an O-200. Kit or stick build, aluminum wings, fabric fuselage, fast and fun.


Sent from my iPhone using SuperCub.Org

 

[Marty57]

If you decide to go with the Cubby; get the Northland CD to update the fuselage to a PA 18 wing attach set up and beef up the fuselage as needed. If you want to build a wood wing, my Wag 2+2 wing is a wood Super Cub wing with flaps, using stock SC flap hardware; drawings can be downloaded from my site. If you want to see what is ahead in a scratch build, take a look at my build site; it's all there since day one. Also, get those wing parts from Frank, they are a gold mine in time savings. My 2+2 build site: marty2plus2.com.
Marty57