WORLD MODELS: Sky Raider Mach I, THE

Model Airplane News, Oct 2004 by Abbe, Peter

Fly better with this aerobatic sport trainer

The World Models Sky Raider Mach I is an inexpensive, entry-level model designed to take novice pilots from their first flight into the worls of basic aerobatics, Featuring a low wing loading and a semisymmetrical airfoil, the Mach I offers gentle flight characteristics and aerobatic potential far superior to that of most trainers. Combine this performance with a complete hardware package, high-quality components, fast assembly time and a price tag judt under $70, and you have a value that's hard to pass up.

KIT CONTENTS

The Mach I is available in yellow and white color schemes; I received a white one. It comes neatly packed with all components, hardware and decal sheet sealed in plastic bags. The wings, fuselage and tail feathers are nicely covered and trimmed with a lightweight, repairable iron-on covering, and all control surfaces are factory-installed with pinned hinges. The World Models has done a good job of building these components as light, strong and accurately as possible. A complete hardware package contains nuts, bolts, pushrods, clevises, control horns, wheel collars, wheels, engine mount, fuel tank, spinner and even foam for mounting your radio and battery. You need only supply a 4-channel radio system, engine, propeller and fuel lines. The 11-page, illustrated instruction manual was easy to follow, although the lack of detailed text may make some assembly steps confusing for true beginners.

* Wing assembly. The wing halves are joined with epoxy and a hardwood dihedral brace; a factory-installed pin ensures accurate alignment. Once the epoxy has set, you must screw the aileron servo onto two plywood plates, which you must then glue to the bottom surface of the wing. All that remains is to connect the pushrods to the preinstalled aileron torque rods.

The wing's plywood center ribs double as the leading-edge hold-down, and the trailing edge is retained with two bolts. The bolt-holes were accurately drilled, and the wing aligned perfectly with the fuselage.

* Tail feathers. To mount the tail feathers, you must remove several small portions of covering and a support block in the tail of the fuselage. Then you can slide the stabilizer and fin into their respective slots and retain them with two steel bolts that are passed through holes in the base of the fuselage. I needed to slightly enlarge one of these mounting holes to achieve proper alignment. Coat these bolts with thread-lock to prevent them from vibrating loose.

* Fuselage. Completing the fuselage is a simple matter of installing the fuel tank, engine, landing gear and radio. After you've assembled the fuel tank, you slide it into a plywood former in the model's nose and retain it by gluing a small balsa stick into place.

The supplied four-piece adjustable engine mount doubles as the nose-gear bracket and easily accommodates the Evolution .46 engine I used. I substituted 6-32 cap-head engine-mounting bolts for the supplied Phillips-head bolts.

After you've passed the nose gear through the center of the engine mount, you retain it with two wheel collars. To actuate the gear, you'll need to install a nylon control arm. Mount the main gear on a hardwood block in the fuselage and hold it in place with two nylon straps. The 2 ½-inch wheels are light foam and fairly small in diameter, but I didn't have any trouble flying off grass or pavement.

The Hitec HS-311 servos I used fit perfectly in the factory-installed plywood servo tray. The rudder and elevator pushrods are steel wires that ride in nylon tubes; these linkages were easy to install and provided a tight, slop-free setup. I did replace the steel throttle pushrod with a Sullivan flexible Nyrod to eliminate the possibility of transmitting engine noise to the receiver. By mounting the battery beneath the fuel tank and the receiver behind the servos, I was able to balance the model perfectly without any added weight.

CONCLUSION

The Sky Raider Mach I is a complete, highquality ARF that can be assembled in a very short time. Its flight performance is fantastic, and its price makes it a value that is hard to pass up! Student pilots should be warned, though: if you show up at the field with this airplane, you may have to wrestle the transmitter out of your instructor's hands!

APC props; distributed by Landing Products (530) 661-0399; apcprop.com.

Evolution; distributed by Horizon Hobby.

Hitec (858) 748-6948; hitecrcd.com.

JR; distributed by Horizon Hobby Inc.

Horizon Hobby Inc. (800) 338-4639; horizonhobby.com.

PowerMaster Hobby Products Inc. (512) 285-9595; powermasterfuels.com.

Sullivan (410) 732-3500; sullivanprodncts.com.

The World Models; distributed in the USA by AirBorne Models (925) 371-0922; theworldmodels.com; airbome-models.com.