Yes, you can do barrel rolls with a trainer. With regard to which radio is best to start out with, you might be surprised at how useful a basic 4-channel sport radio will be even years from now when you're using it with sport planes, as a buddy box, or as a controller for a PC flight sim. You'll eventually want a more advanced computerized radio, but you don't need one right out of the gate.

I personally trained and solo'd on a Nexstar Select RTF a few years ago. Since that time, I've built and flown a Tower Trainer .40 MkII ARF with an O.S. .46 FX. More recently, I helped a good friend purchase an Avistar Select RTF from a gentleman who bought it then decided he didn't have time to fly it. We have flown the Avistar as my friend's primary trainer with the O.S. .40 LA and Futaba SkySport 4 radio.

The Tower Trainer .40 MkII ARF is, in my opinion, most likely supplied by the same factory that makes the Nexstar and Avistar ARFs for Hobbico. I am fairly certain of this because the wheels, fuel tank, and engine mount supplied with my Tower Trainer .40 MkII ARF were the identical parts supplied with my Nexstar Select RTF. I think it's important to note this, so that a prospective buyer can rest assured that all three planes will feature similar design and quality characteristics.

Having flown all three of them in the role of primary training aircraft (one as student and two as instructor), I am also comfortable comparing the flying characteristics of all three airframes and making general comparisons between the three.

Of the three airframes, two suffer from similar covering problems while a thirds seems less prone to trouble. All three are covered with Monokote, and the primary covering job is well done on all three aircraft. For some reason, however, keep trim pieces stuck down to the Nexstar or to the Tower Trainer .40 MkII seems like a full time job while the Avistar seems less prone to these kinds of problems. Window decals and stripe pieces will peel off Nexstars and Tower Trainers like Chaquita stickers peel off bananas. Why Avistars seem to hold up better I have no idea, but they do.

Based on my experiences, I have found planes covered with Ultracote tend to be less succeptable than Monokote covered ARFs to bubbling and sagging as the seasons change and easier to smooth out with heat gun or iron. If top quality covering and low maintenence requirements for the ARFs covering are a priority, then trainers from Goldberg or Hangar 9 should be considered.

Again, with regard to flying characteristics, one stands out from the others. I found both the Tower Trainer .40 MkII and the Avistar to have very good consistent and neutral handling characteristics in a wide variety of wind and weather conditions. The Nexstar is easier than the other two to land for a novice, having more of a classic "floating" landing charactistic than the other two designs. This floatiness comes at the price of windy flying characteristics. The long wing chord and longer wing span of the Nexstar make it more succeptable to wind buffetting than the other two and it can be more difficult for a student to turn in breezy conditions.

The Myth of Semi-Symmetrical Wings on Trainers

This opinion is going to ruffle some feathers as it tends to challenge popular opinion. Based on my trainer experiences, I believe that shallow versus deep dihedral is far more important to a trainer wing's "sport handling" characteristics than whether that wing is flat-bottomed or semi-symmetrical. When comparing trainer wings, it appears to me that "semi-symmetrical" is simply a fancy marketing term for "not quite completely flat bottomed. Comparing the wing rib of an Avistar to the wing rib of a Tower Trainer .40 MkII will show you how really small the difference between the two designs is. I'm not suggesting that a semi-symmetrical design doesn't contribute at all to improved aerobatic characteristics on a trainer, only that the contribution of that factor (flat or semi) alone isn't enough to automatically rule one out over the other.

When I built my Tower Trainer .40 MkII ARF, I wanted it to fly a little sportier than the most basic of trainers. The ARF manual recommends building the wing with about 5 1/2 inches of dihedral. I did a little extra sanding on my wing joiner to flatten mine out, and it came out at about 3 3/4 inches of dihedral. When I flew the plane, I was surprised to find that my flat-bottomed wing trainer was as aerobatic and could fly in the wind as good as Avistars in the club could.

This caused me to go back and look at what else was different on most of these sport trainers w/ semi-symmetrical like the Avistar, the WM Sky Raider Mach I, and Hangar 9 Arrow. To an airframe, all of these sportier trainer designs also featured wing dihedral much flatter than more traditional designs like the Sig Kadet or GP PT-40. It's the high amount of dihedral that causes traditional trainers to roll less gracefully, it's high dihedral that causes traditional trainers to tend to fall out of loops, and it's high dihedral that make many traditional trainers feel so much more succeptable to wind buffetting.

In theory, I know that a semi-symmetrical airfoil is "cleaner" by design than a flat-bottomed airfoil. I just think that, in terms of real-world sport flying with ARF trainers, that semi-symmetrical wing design ends up being about as important as the rear spoiler on the hatchback of your typical Mazda. The vehicle is going to spend 98% of it's time operating in conditions where it makes no apparent difference.

In Conclusion

I liked my Nexstar while I was flying it. It was a good looking airframe and it was very easy with which to learn to land. If I ever bought another one, it wouldn't be the RTF version. I probably would never buy another one, however, because taking out the steep dihedral would require significant modifications and flying conditions are simply too windy where I live to enjoy the stock Nexstar most of the time.

I believe that any pilot looking for a quality primary trainer would be equally well served by either an Avistar or a Tower Trainer 40 MkII. I believe that the perfect engine for either of these airframes is the O.S. Max .46 LA because of it's light weight. More power isn't necessary to fly either of these airframes even in a very aerobatic manner, and a 17 ounce ball bearing 2-stroke makes the airframe difficult to balance without adding weight. Too many students put heavy ball-bearing .46s on their Avistars and then struggle to learn landings because their trainer is nose-heavy and lands hotter than it should.

I believe that any pilot concerned about the appearance and longevity of the trim scheme of his aircraft would be well served by spending $30 extra on the Avistar and then $4 extra on an exhaust deflector for his muffler. If a pilot already owns a Super Tigre G-45 ABC engine that he wishes to use. I think he should look instead to the Hangar 9 Alpha .40 ARF. The Hangar 9 Alpha .40 is designed to balance properly with a heavier ball-bearing .46-size engine. The H9 Alpha .40 ARF is also covered and trimmed in Ultracote, and it will stay looking new for much longer than the other airframes previously mentioned.

Hopefully my opinions at least seem informed when weighed with their given explanations. Good luck and good shopping!