Sizing up warbirds

Model Airplane News, Jan 1999 by Yarrish, Gerry

WARBIRDS ARE models that translate well into larger formats, and when I say larger formats, I mean 72-inch spans and bigger. There seem to be fewer and fewer 60/60 (.60-size engine and 60-inch wingspan) warbirds showing up at the flying field these days, and if I were to venture a guess, I'd say that the average size of a large warbird is about 90 inches. Larger and smaller models are, of course, also around, but today there are more kits and semi-kits available for giantsize warbirds than you can shake a sheet of balsa at.

For me, the 80- to 85-inch-span warbird makes good sense. At this size, models begin to benefit from larger wing areas and so tolerate higher wing loadings. "Bigger flies better" is the battle cry, isn't it? Gas engines fit more easily within the model's nose, and in general, the 80something model is big enough to be impressive while still remaining fairly easy to transport. They also cost less to build when compared with your typical 100inch warbirds. Where's the downside? I think big-name companies are also finding this out, and the proof is on the hobby shop shelves.

BIG GOLD EDITION MUSTANG

By now, most of us have heard of the 1/5-scale Top Flite* Gold Edition Mustang. Since I have flown both the 1/7-scale Gold Edition P-51 and P-47 Thunderbolt, I was very pleased to see that with the new Mustang, Top Flite had turned its attention to bigger warbirds. With an 84.5-inch span, 1,245 square inches of wing area, a 17.5- to 19-pound, ready-to-fly weight and a 36.9 ounces-per-square-foot wing loading at 20 pounds, the big P-51 looks pretty inviting. Flying buddy Bill Steffes had started a "Field and Bench" on the big Mustang but unfortunately, the test P-51 was done in by radio problems before a full evaluation could be done. Here's what he found.

At first glance, Bill thought that the Mustang would end up weighing more than the advertised weight. But after completing it, Bill was pleased that with a simple MonoKote*and-paint finish, the P-51 weighed exactly 20 pounds.

Construction is typical for a Gold Edition kit, and the parts fit is very good. The design is straightforward and fairly uncomplicated for a warbird that's equipped with flaps and retractable landing gear. Though it took slightly longer to build than Bill had anticipated, he was very pleased with the outcome.

ENGINE AND ACCESSORIES

For power, the P-51 was outfitted with the U.S. Engines* 41cc gasoline engine. The U.S. 41, including its canister-style muffler, fits almost completely within the removable chin cowl. There wasn't enough time to properly sort out the engine and prop combination, but properly broken in and propped, the U.S. 41 should produce adequate power for the Mustang. In speaking with Great Planes* about its newest big Gold Edition warbird-the F4U Corsair-we were told that the tJ.S. 41 is powerful enough for their big bent-wing warbird, and this plane weighs 25 pounds.

Robart* pneumatic retracts are a perfect fit for the Mustang and add greatly to the scale look of the model. Bill went to the trouble to add a Robart retractable tailwheel.

Flaps are included on the plans, and there's no reason not to build them into your wing. Also, the wing-to-fuselage fairing is a must-do for a good-looking warbird.

Bill used 10 servos in the Mustang, including a separate servo for each flap and aileron, two standard servos for the elevator (one for each half), and one each for throttle, retract valve, rudder and the tailwheel steering. The wing is fully sheeted, and the kit comes with extra-wide balsa sheeting to minimize the number of seams. The tail feathers are built up, airfoil-shaped surfaces. The finish is silver MonoKote with an overspray of olive drab LustreKote*. Black and white invasion stripes give Bill's Mustang an authentic "Normandy invasion" look.

With a lMs-scale Mustang and Corsair in the Top Flite hangar, those who think big have two good reasons to consider a warbird for their next project-if only they'd come out with a big P-40 Warhawk!

CANADIAN SPITFIRE

If you like your warbirds big-and I mean really big-our northern friends at Clark Industries* offer a very complete package. Though not brand-spanking new, their 1/4-scale, 42-pound Spitfire surely would look impressive sitting on anyone's flightline. Available in both the Mk IXB and Mk XII versions, the Clark Spitfire kit comes complete with engine and retractable landing gear. The fuselage is made of hand-laid fiberglass and polyester resin and features all the panel lines molded in. The firewall and wing blocks come factory installed, and the Spit features internal air ducting for enc cooling. The 112-inch-span wing is built up, and the Clark Failsafe retractable landing gear have stout, 7/8-inch-diameter Oleo struts and a retract cycle rate of 3 to 4 seconds. Twin actuators move the gear, and 5.5-inch Du-Bro* tires complete the landing gear. As the name implies, if air pressure is lost, the gear come down and lock into place. A scale cockpit kit containing over 100 pieces is also available.