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The Great Planes
Extra 300S comes very well packaged with the wood bundles neatly banded together.
The hardware packages are grouped according to function. The canopy is well
protected to avoid scratches being caused by rubbing against other parts.
The ABS cowling and wheel-pants are included, as is the pre-bent and drilled
heavy-duty aluminum landing gear. The plans, which are very well done, consist
of one large rolled sheet and an excellent instruction book with many pictures
detailing the building process. The plywood and balsa provided is excellent
quality and the parts separate cleanly from the sheets.
The building process is conventional beginning with the tail feathers and progressing to the wing and fuselage. The processes used yield a straight fuselage and wing halves. When covering the turtle deck, the balsa sheeting must be wetted thoroughly to get a good fit. A little extra time at this step pays big dividends later during the covering of the model. The wing construction is the basic D-tube arrangement. Special care must be taken when building the wing to ensure that the rib alignment tabs do not get broken off during the assembly. The tabs are lightly scored to facilitate easy removal when the wing is finished. Some may break off and may be lightly tacked with CA during construction. Thinned epoxy was used to apply the fiberglass center reinforcement instead of CA as recommended by the instructions. An OS 46FX with a Slimline Pitts style muffler and a 11 x 6 Zinger wood prop was chosen to power the Extra 300S. Provisions must be made for filling the fuel tank. A Great Planes EZ Fueler was chosen for this task and a bracket was fabricated and installed next to the engine so that the filler would mount flush with the cowl. The ABS cowl and wheel pants were cut out and test fitted until the desired fit was reached, then glued with CA. Once the halves were glued, measurements were taken to make the cutouts for the engine and needle valve openings and muffler. A Dremel tool simplifies the work of shaping the openings. The inside surfaces were roughed up with 200 grit sandpaper and a layer of light fiber glass cloth was applied using a mixture of 15 minute epoxy thinned 50% with alcohol. This thinned mixture made the application of the glass cloth extremely easy. After the epoxy had set, the seams were filled with Squadron Putty and sanded smooth. An additional square of glass cloth was centered over each attachment hole in the fuselage. The plane was filled with a light filler compound and sanded then covered in Missle Red Monocote with white Monocote trim. The stars were cut out using computer generated templates and sized until they matched requirements. The base color was applied and the trim, white stripes and red stars, was applied using water with a small amount dishwashing detergent and then allowed to dry overnight. The trim was then sealed with the iron set to a low temperature. The cowl and wheel pants were spray painted using Top Flight matching Lustrekote paint. The final assembly consisted of attaching the cowl, wheel pants, wheels, pilot and canopy and installing the radio equipment. The control surface throws were set to the limits specifified by the instructions. The instructions must be followed exactly at this point. Even though the throws seem too small, they are not. Surprisingly, the plane balanced without the addition of any extra weight by positioning the battery and radio appropriately. The new OS 46FX was broken in by running a couple of tanks of fuel through on a test stand. The Extra was then taken the field. The OS 46FX with the Slimline Pitts muffler sounds great in the enclosed cowl. The idle was adjusted, the control surface directions were double checked and the model taxied out on the runway. There was a breeze at about 45 degrees to the runway. As power was applied, the Extra accelerated rapidly and lifted off at a little over half throttle. It flies as if on rails. At this point, it is obvious why the throws are as recommended in the directions. Rolls are very axial, stalls are straight ahead and recoveries are easy. Snaps are violent as expected. Inverted flight requires only a touch of down elevator. Landings are straight-forward as long as the model is not forced to float in like a trainer. The Great Planes Extra 300S is a quality airplane and the kit is typical of what is expected from Great Planes. The 40 size Extra 300 was chosen because of the desire for something fast that would get the adrenaline going, look great, and yet be small enough to carry in a car trunk. The GP Extra 300S met and exceeded all expectations. This airplane will do anything that the average pilot is capable handling and more. It is not for the novice but is a step up from a low wing trainer. This is one great plane (pun intended). |
