Piper Skycoupe (oz1207)

About this Plan

Piper Skycoupe. Free flight scale model of the 1940's prototype tricycle gear, twin-boom pusher from Piper.

Quote: "PRIOR to the war, the Piper Aircraft Corp was one of the leading lightplane manufacturers, setting the pace for other firms in the development of aircraft for private ownership. Among other things, it has brought the airplane into the price range of the greatest number of enthusiasts, while always keeping in mind the fact that safety is of prime importance to the sport flyer. In view of this fact, their engineers have presented to the public airplanes that practically fly theniselves. It is because of this inherent stability incorporated into Piper's designs that they lend themselves so readily to adaptation as flying scale models.

Now, once again, Piper has come up with a ship that seems to show great promise. This time it is something radically different to the conventional design, sporting such features as internal engine-mounting, pod and boom fuselage arrangement, low wing, tricycle landing gear with two wheels retracting, comfortable cabin design, and many more. It departs most obviously from the 'normal' ship in having the prop mounted at the rear of the fuselage, making possible the excellent visibility from its large cabin. As yet, the Piper 'Skycoupe' is in the experimental stage, undergoing its 'de-kinking treatment.' However, sufficient information is supplied by Piper's engineering staff to make it possible link to build a model of the ship that may be one of America's favorite light planes.

The model was not designed to give the over-powered, skyrocket performance of a contest job, but was designed more along the lines our good friend, Bill Winter, described as: nice and slow and easy; realistic for a change. The ship is just that.

The model was made rather large in order to house a class 'B' motor. It goes without saying that the model can easily be made to house a class 'C' motor; the only necessary alteration being to change the size and spacing of the motor mounts.

Because of the unusual shape and fittings on this job, it is necessary to follow a certain procedure to avoid getting into some pretty awkward positions. This is obvious at a glance, for you will notice that the root section of the wing is an integral part of the fuselage, The rudders are built as part of the boom construction, and the booms in turn are securely mounted to the wing stubs.

The first thing to do, after carefully studying the plans, is to make the root section of the wings. Complete this construction, omitting the sheet balsa covering. Now you can start on the fuselage. Cut out the keels and bulkheads and assemble them. Insert the motor mounts and cement securely. At this point you assemble the wing root sections to the fuselage and build in the motor cooling duct.

Installing the landing gear securely at this stage will eliminate the confusion that would result from trying to do it after planking. The exit of the cooling system at the rear of the fuselage is the first part to be planked; then the remainder of the fuselage. It is important to note at this time that the complete pod is planked, including the window section. The reason for this is that the fuselage itself serves as a pattern for molding the celluloid windows, thus avoiding the difficult and time-consuming operation of making a mold to do the job, and also assuring a more perfect fit of the windows.

Before attempting to mold the celluloid for the windows, the fuselage should be completely doped and finished. This will prevent any moisture from the molding process from swelling or warping the wood. There are several methods of forming celluloid, such as boiling it in water or oil to make it pliable enough to be stretched around a pattern or form. However, due to the thickness necessary to allow such a deep draw as the front window of this model, these methods are impractical. The oil method works very well; the only drawback being you would need about a five gallon drum of oil to work in. The reason for this is obvious from the size of the pod. The oil must be heated to at least three hundred degrees and the complete drawing operation must be done while the celluloid is immersed in the hot oil. This method would be very good for smaller shapes, hut, in this case, after many attempts under poor conditions, it was decided thaf the only way to do the job with ease was to use a softening compound on the celluloid and then stretch it over the fuselage..."

Note this is not a full size plan, this is a scan of the magazine pages as printed.

For a full-size version of this plan, see Piper PA-7 Skycoupe (oz11203)

Supplementary file notes

Planfile includes article.

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