March 2011 Issue
Letís compare a covey of Cub-like homebuilts.
The venerable Piper J-3 Cub always seems to bring a warm smile to the faces of aviators. There is something essentially appealing about the unadorned simplicity of the Cub. It represents flying in its purest form, unencumbered by the trappings of modern life. Somehow it transcends the competition, using its charm and short takeoff and landing prowess to overcome its lack of speed and, in some cases, cabin size.
The Light Sport Aircraft rules created a market for lightweight airplanes such as the Cub, and streamlining the manufacturing and approval process has made them somewhat affordable. Please don’t start throwing things while yelling, “How affordable is a $100,000 Cub?” That is a lot of money, but it is relatively affordable compared to a quarter-million bucks for a new Cessna 172. If you build it yourself, you can get in for less than $100,000 in most cases.
For our comparison I have focused on kits that meet some basic Cub-like criteria. Each plane must be a two-seat tandem taildragger, it must be fabric covered, it must be flyable under Light Sport Aircraft rules (either as an Experimental/Amateur-Built or an Experimental Light Sport), and it must be available as a kit. My search originally included five airplanes, but the Savage Classic (now Savage Cub) that was originally available as an ELSA kit can now only be purchased as a factory-built airplane. The four that remain are the Wag Aero Sport Trainer, the Texas Sport Cub by American Legend, the CubCrafters Carbon Cub and the RANS S-7S Courier. There are other Cub-like aircraft—including a trio of products from Backcountry Super Cubs—that might also be on a Cub-type shopper’s list, but Backcountry’s designs are all closer to the heavier, non-LSA Super Cub. We hope to cover these in an upcoming issue of the magazine.
For this article, I aimed to bring a builder’s perspective to the process, so I paid special attention to building instructions, completeness of the kit, feedback from builders and dealing with the respective factories. I also flew each plane enough to get a feel for it and identify any notable quirks, but not enough to do a complete evaluation of flying qualities. Others have covered that ground in this magazine for all but the Savage Classic.
Let’s look at each kit separately and then we’ll make some comparisons at the end.
Looks like a Cub because, basically, it is a Cub. Wag Aero’s Sport Trainer is the closest thing to a J-3 in this group.
Wag Aero Sport Trainer
The Wag Aero Sport Trainer enjoys the longest track record and is the truest to the original J-3 Cub. Hundreds of plans sets have been sold. The plane includes wing tanks, which were not available in a Cub until the J-5 model, and will accommodate a range of engine options beyond anything Piper originally offered; otherwise, it is about as close to a J-3 Cub as you can get. For someone who wants to create a brand new Cub that is as true as possible to the original, this is your only real choice outside of restoring an actual J-series.
Wag Aero appeals to a wide cross-section of builders by offering plans, pre-welded components and quickbuild kits. For a builder on a tight budget, this has a lot to recommend it. With a few thousand dollars you get a set of plans and a bundle of tubing to get started. If you do all the welding and other work yourself and keep the panel simple with no radio, you can get into a finished airplane with a used Continental A-65 engine for around $45,000, maybe less if you are a good scrounger. Getting all the quickbuild options will cost about $10,000 more, but will save hundreds of hours of build time. Another $10,000 to $12,000 will get you a brand new O-200 engine. A budget of $75,000 for a complete plane is reasonable if you want all new stuff, all of the quickbuild options, and a panel with a radio and transponder. Of course, you can really blow the budget with the instrument panel, but there is no need to. It is a Cub, after all.
The back seat is cramped for larger pilots.
What’s good about the Wag Aero? Lots. It looks like a Cub, it flies like a Cub, and it practically is a Cub, only better. It carries fuel in the wings, so it can be soloed from the front seat. It is an Experimental, so you can customize it without worrying about STCs or field approvals. It can also be built more cheaply than its competitors if you are willing to do some extra work. Wag Aero can set you up with engine mounts for most of the smaller Continental engines or the Lycoming O-235.
What could be better? Well, there are a few things. It is just as tight in the cabin as a J-3 Cub, especially for big guys. I had to take my size 13EE shoes off to work the rudder pedals from the rear seat. Front legroom for my 6-foot-3 frame was painfully tight to the point of being almost unendurable.
And the front perch isn’t exactly spacious. But there’s panel space sufficient for VFR instruments and radios.
Another issue is that the plans are a study in minimalism. If you have built a GlaStar or an RV, you will be taken aback by how little information there is. A Wag Aero builder at my local airport described it: “The plans are really sparse. What I really used to build the plane was the exploded views in the parts catalog.” That is not to say that you can’t build the plane with the plans, but you won’t be spoon fed the information; you’ll have to work for it. Originally, the Sport Trainer was limited to 1200 pounds, which doesn’t leave quite enough payload when the heavier engines are used. But now the company has revised its recommendations and allows the full 1320-pound LSA-legal max weight.
Texas Sport Cub
Full disclosure and a reminder for those who missed my series on it: I built and now own a Texas Sport Cub. When I made my decision, the Carbon Cub was not available in kit form, and the Wag Aero got eliminated for the legroom issues mentioned. I looked hard at the RANS S-7S but went with the Texas Sport for the purely emotional reason that it looked more like a Cub.
American Legend has built at least 150 Cubs as SLSA airplanes, and they are well regarded. The company’s kit division, Texas Sport Aircraft, has sold a much smaller number of kits, but that part of the business is gradually gaining momentum. The plane actually uses many Cub parts, but offers a number of improvements that make it more comfortable and flexible. Like the Wag Aero, it carries fuel in the wings, so it can be soloed from the front or back. It betters the original Cub and the Wag Aero when it comes to interior room. The cabin is 4 inches wider and has more legroom. The Texas Sport Cub also features doors on both sides to make getting in and out easier, an especially nice feature if you put it on floats. With its 1320-pound gross weight, which can be bumped up to 1600 pounds if you order the beefier wingspars, it can handle the 100-horsepower Continental O-200 or the 120-hp Jabiru 3300A. (But then it’s not LSA legal, but you knew that.) Texas Sport Aircraft is the only one of this group to provide factory support for the Jabiru engine installation.
Texas Sport’s homebuilt version is virtually the same as the SLSA (ready to fly) model. It benefits from a wider cabin and other modern amenities.
Price wise, the Texas Sport is a bit more expensive than the quickbuild version of the Wag Aero, but it comes with more of the work done. For example, I built mine for about $82,000, including a new Jabiru engine, a Sensenich composite propeller, and a nice VFR panel with a Dynon FlightDEK-D180, Garmin SL40, Garmin GTX 330 transponder, intercom, and a Garmin GPSMAP 496 in an AirGizmo mount. That included paying a professional painter to help with the color coats and lightning bolt. Some money could have been saved by going with a used or overhauled Continental engine, and I could have picked up a used 396 on eBay, but getting the plane flying for much under $75,000 is unlikely unless you completely eliminate the radios. The price comes from the kit being available only as a quickbuild with everything welded and the wings mostly assembled. You can avail yourself of the factory builder-assist program, but that further increases the price. Factory assistance and a factory paint job will push it up to $100,000 or more.
Flying the Texas Sport Cub holds no surprises. It flies like a Cub. There are no flaps, so coming in high means slipping it. Just be careful if you have both windows open. The first time I slipped, the wind blew right through the cockpit and took my hat and headset off. The other thing you need to watch is the forward center of gravity when flying alone from the front seat. In flight it is no problem to trim the plane for level flight, but it would be easy to put the plane on its nose when landing if you are not careful with the brakes. It’s best not to use them at all until you are slowed and off the runway. The Texas Sport Cub is not unique in this regard. All of these planes require judicious use of the brakes when flying solo from the front.
Up front can be the Continental O-200 or the Jabiru 3300, in either a closed or open cowling (open for the O-200 only).
There is much to praise about the Texas Sport Cub. The extra room is really nice, though front legroom is still a bit tight for me. Most of the kit quality is first rate. Parts fit and are well organized on cardboard panels. Many upgrades are available from the factory including interior pieces and pre-wired instrument panels to suit any budget. While most of the parts are nicely done, the few fiberglass parts in the kit, including the boot and engine cowls, are not. They need to find a new vendor for these parts. The people at American Legend/Texas Sport are friendly and helpful in a casual, laid back sort of way. They always got me what I needed, but more tightly wound individuals might grow anxious with the relaxed pace and lack of attention to certain details.
The Texas Sport Cub goes without flaps but performs admirably in short-field work.
The assembly manual needs to be improved. It has lots of nice color pictures and adequate, if less than detailed, written descriptions of most of the assembly steps, but no extra diagrams or comprehensive parts list. At the time of my project, a number of sections were not put together at all. This required numerous phone calls and emails to get the information needed, which worked out well enough, but could hardly be characterized as top rate. Of course, if you opt for the factory assist program, the assembly manual’s shortcomings aren’t an issue.
The Carbon Cub is larger than a standard Cub, and has ample room front and back.
Texas Sport also has not broken a lot of new ground when it comes to refining the basic structure and controls of the airplane. Many of the parts look just like they did 70 years ago when the J-3 Cub was first introduced. Some of their competitors have introduced refinements to the manufacturing process that save weight and simply work better than parts patterned on the original design.
Carbon Cub EX
CubCrafters offers the Carbon Cub EX kit, which has become the current ultimate expression of the Cub concept and is priced accordingly. Does that make it the best? If you want to build a new Cub and you have only $50,000, you will only end up with at most half a Carbon Cub. If you want a large builder group and a well-developed support network, you won’t get that either, but the company is expanding its builder base and has some excellent builder-support services in place.
Split doors are a Cub trademark. The Carbon Cub’s can be open in flight.
If you want the coolest, most beautifully crafted carbon-fiber parts and a boatload of slick CNC-machined aluminum, and you don’t care what it costs, you’ll want a Carbon Cub kit. The bad news is, depending on what panel layout and engine are selected, you will spend well over $100,000.
If the prospect of forking over that amount hasn’t left you on the floor gasping for air, you need to look at some of the unique features found on this airplane. Unlike the Wag Aero and Texas Sport Cubs, the Carbon Cub has flaps—nice, big, effective flaps that allow for steeper approaches and some short takeoff and landing rolls in the hands of a crack Cub pilot. At Valdez in 2008, a stock 100-hp Carbon Cub put together a score of 66 in the STOL competition. This means that when you add the takeoff roll to the landing roll and divide by two, the average of the two distances is 66 feet—and that was with a Continental O-200 engine. Don’t expect to do this at home unless you are one heck of a Cub pilot, but the capability is there.
Amphibious floats for your Carbon Cub? You bet!
CubCrafters also offers a 180-hp O-340, based on the venerable Lycoming O-320 design that employs every weight-savings trick in the book and uses ECI parts including a stroker crankshaft. With an empty weight of around 920 pounds this is effectively a single-place airplane and is probably best registered with the allowable higher gross weight of 1865 pounds (Though, again, it’s no longer LSA legal.)
With those big flaps, flying the Carbon Cub is more like flying a Super Cub than a J-3. It flies great but refuses to stall. It has an adjustable front seat that actually feels comfortable. It also dispenses with the J-3’s heel brakes and includes what most people would consider more normal toe brakes. Except for the price, there really isn’t much to complain about.
RANS S-7S Courier
Even though the RANS S-7S is similar to a Cub in many respects, it makes no attempt to be a Cub. With its squared-off rudder and wingtips, it doesn’t look much like a Cub, and its Rotax engine doesn’t sound like a Cub, but that doesn’t mean it isn’t worth considering. RANS has a longstanding and well-deserved reputation for turning out a good product.
The current model S-7S is a solid design that flies well and is easy to build, as hundreds of builders can attest. It is lighter than the others in our group, with a maximum gross weight of 1232 pounds, 98 pounds less than the max for Light Sport. This means everything on the plane is lighter. For one, it uses the Rotax 912S engine, which is a good 30 pounds lighter than the new lightweight Continental O-200. The structure of the S-7S is also lighter throughout. The result is an empty weight of about 100 pounds less than the Cubs.
A low instrument panel improves over-the-nose visibility.
Cost wise the S-7S is toward the low end of this group. Complete with a radio, Garmin 495 and transponder but no quickbuild options, it can be built for well under $70,000. Subtract about $6000 more if you are willing to forgo the radios and GPS. If you are really in a hurry to get flying, RANS will assemble and cover the wings and do a host of other chores for an extra $9300.
RANS gets a lot of things right with the S-7S. It is comfortable inside, with adjustable seats that would fit almost anyone. The well-balanced controls give it a nice feel in flight—somewhat lighter than a Cub and with less adverse yaw. Effective flaps help the plane get on and off the ground quickly, and visibility is great. The quality of the assembly instructions sets the standard for this group. A complete and well-documented kit makes building the S-7S quick and relatively painless for most builders. RANS also has an active and helpful builder support group called the RANS Clan. This is an important resource, especially for first-time builders.
The engine of choice for the RANS design is the Rotax 912S.
The S-7S doesn’t have any big negatives, but it is a more lightly built airplane. Does that mean it can’t stand up to the rigors of backcountry flying? For most pilots, I don’t think this is a concern. Is it as tough as a Cub? Well, I’m sure we could argue the point, but it really doesn’t matter. It is a good plane with a good track record, and that is probably enough to say.
One thing I did notice flying the S-7S is that when it was loaded up with two people, it would consistently drop a wing going into a stall. I thought it might have been a quirk of the one airplane, but since then I have flown another that did the same thing. Still could be an individual-airplane thing, but you do have to wonder. To be sure, the stall in both airplanes came at an impressively low airspeed, but you had better not let your feet be asleep when it begins.
Winner of the “which one is unlike the others” contest is the RANS S-7S, a high-wing, tandem-seat, LSA-legal utility plane that competes in many ways with modern Cubs.
As you might expect, these four planes share a number of traits. They all can land in a few hundred feet, and they can take off again in about the same distance. They all are hard-pressed to fly much faster than 100 mph (except for the Carbon Cub with the big engine), and 90 is more like it. Within 3 hours they all need to be on the ground again so that you can get some gas and stretch your legs. With two aboard, you won’t be able to carry a week’s camping gear. They all fly well enough to serve as good trainers for even novice pilots, taildragger gear notwithstanding. And they are all fairly easy to build, if you opt for the pre-welded fuselage on the Wag Aero. Two people working on one of these kits a full day every Saturday could expect to be flying in a year or less.
The best kit always comes down to a unique balance of practical and emotional wants and needs. Each of these kits makes a good plane, but each has special attributes that will make it better for some builders than for others. If you have more time than money, aren’t oversized like me, and really want to build a plane that captures the spirit of the Cub, the Wag Aero may be best. If you want to build a plane, especially as a first-time builder, that represents a great value and at least loosely follows in the path of the original Cub, then the RANS S-7S may be your best choice. The Texas Sport Cub has a great combination of Cub qualities with some important improvements. It is not difficult to build and not too expensive. It improves on the original in many ways but retains the spirit of the Cub. I am certainly in no hurry to replace mine. Finally, the Carbon Cub rounds out the field with the best features in many ways, but at a price.
The best part of this story is that there are a lot of good choices. If you are thinking about building a Light Sport airplane, take a look at these four possibilities. They may not be the fastest ships in the air, but they sure are a lot of fun to fly, and they’re pretty fun to build, too.
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