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Chapter 4 - Troop-Carrying Glider

Powerless flight is a beautiful and awe-inspiring sight, not only with full-scale gliders, but with models as well. These craft are towed aloft in kite-like fashion and are disengaged when they reach the maximum altitude allowed by the towline. From then on, they circle gently, searching for helpful air currents which will keep them in the air longer than most engine-powered models. Fortunately, virtually all full-scale gliders are adaptable to model operation.

Prior to World War II gliding was regarded by all except a few as a truly peaceful sport with no adaptability to warfare. This was, of course, an erroneous assumption, as was proven at Crete and Normandy. Gliders have proven to be an indispensable weapon in the hands of an invading army. The invasion glider most used by the United States during World War II was the "Waco CG-4A". Over 10,000 of these useful, engineless airplanes were built by Waco, Ford, Cessna, and a dozen other manufacturers. These planes can carry 15 fully armed soldiers or an equal weight in equipment or ammunition. Once loaded, the glider is towed aloft by a conventional airplane which continues to tow until within gliding radius of the objective.  The objective is usually a pasture or open field. When the towline is released, the towplane turns homeward while the glider silently soars down to a landing. Skids are used in lieu of wheels because of the rough surface of most of these fields and pastures. Immediately upon landing, the troops scramble out and proceed with their assignment. Should they desire to evacuate the area, the pick-up plane could return and, without landing, pull the glider into the air by means of an ingenious grappling device.

Plans for the replica of these famous gliders are presented one-half size and therefore must be enlarged before construction can start. When this has been accomplished, the fuselage side view should be traced onto sheet balsa of the thickness specified on the plan and cut to shape with a single-edge razor blade. Two sides are required. Cement the reinforcing strips to the inside of each side and then join these sides at the rear at the angle indicated in the top view. Hold together with straight pins until the cement has dried. Cement the five "cross-piece" balsa strips between the two sides and set aside to dry.

The top and bottom sheet-balsa fuselage covering should be applied with the grain running crosswise so that the balsa will readily bend with the fuselage contours. Application in this manner also adds considerable strength to the fuselage. Do not attempt to cover the top or bottom in one piece; rather, rough-cut small sections and cement these in place. When the covering is complete and dry, carefully trim the edges flush with the fuselage sides, using a single-edge razor blade.  Sand the entire fuselage smooth with 3/0 sandpaper.

"The  Lensman"  Photo

In order to preserve the excellent flying qualities of our Waco glider, we omitted the take off wheels and landing skids. Star is a decal while window portholes are gummed paper. Cockpit frames and wing stripes are white "Wondur-cal". These stripes were used only on all aircraft during the "Normandy Invasion" during World War II and, therefore, are optional.

The wing structure on this model is typical for free-flying models, whether they be rubber-powered, gas-engine-powered, or glider. Trace and cut out the ribs from sheet balsa and pin these together evenly, side by side. Wrap sandpaper around a block of wood and sand all of these ribs together in order to make certain they are all shaped alike. The ribs can also be notched for the spars and leading edge at this time. The wing is made in two panels. Pin the lower spars and trailing edge to the work table directly over the plan. Follow this by pinning all the ribs in place and applying cement to all of the joints. Fit the upper spars into the rib notches and pin the leading edge in place. Apply cement. It will be noted that the leading edge is installed on edge. Cut the sheet-balsa wing tip and cement it to the end rib while the upper spars are cemented to the edge of the tip. The procedure for building both panels is identical. Be certain to make one right and one left wing panel. Remove the pins when the joints are dry.

Gently sandpaper the structures. The trailing edge must be cut with a sharp knife or razor to a triangular cross section, as the plans indicate, in order to fair with the wing-rib contour.

A material called "Lightweight Silkspan" is used for the wing covering.  This paper is the same as is used for teabags.

It will not break apart when wet and has the attractive feature of shrinking when dampened. All hobby supply shops sell "Silkspan". The wing should be covered with the grain of the paper running spanwise( parallel to the spars). This adds strength to the unit and increases the lifting capacity of the wing by preventing excessive sagging between ribs. Cut the covering roughly to a size that will cover both sides of one wing panel. Allow at least a one-inch margin all around. The adhesive used is thick, clear dope or thin, slow-drying cement.

First, apply cement to the top of the trailing edge and quickly attach one end of the covering to it, spreading and smoothing it with the fingers. This is your anchor. From here on, the objective is to cover the wing by wrapping the paper around the leading edge and back to the under side of the trailing edge; in doing this, try to apply the adhesive to as few components of the structure as possible. It is advisable to apply the adhesive next to the upper edge of the extreme ribs (root and tip). Working fast, attach the paper to these ribs, again using the fingers to smooth and tighten the covering. Next, apply adhesive to the under edge of these same two ribs and wrap the covering over the leading edge and onto the other side of the structure. The final phase is to stick the covering to the under side of the trailing edge. Should it develop that certain areas did not adhere to this outline structure, the adhesive can be applied over the paper and pressed gently with the fingers. It will seep through the covering and hold it to the structure. The wing tip is covered in two pieces, one for the top and one for the bottom.

Pin each covered panel to the work table or other flat surface. Obtain a wad of absorbent cotton, soak it with water, and gently dampen the covering to shrink it. The wing is pinned in order to prevent warps. When the "Silkspan" is dry and taut, two coats of clear dope should be brushed on. This solution makes the covering both airtight and waterproof, stronger, and more taut.   When the second coat is thoroughly dry, the panel can be removed from the table . Although it will not be possible to pin it down in the manner described above, water and dope the other side. Once both wings have been completed, they can be cemented together by joining at the root ribs at the proper angle.

The Lensman"  Photo

Taken at the instant of pickup, this photo shows the "Northrop Gama" model described in Chapter Five lifting the towline loop off of the two poles. An instant later the glider was on its way trailing the towplane by about twenty feet.

Component parts of the "pickup system" consists of two broom sticks placed eight feet apart. A 3 inch headless nail is driven into the upper side of these poles as can be seen in the photograph. The towline is a figure "8" of nylon string about 3/32" diameter. One loop of this figure eight is eight feet in diameter while the other is two. Afix this smaller loop to the glider harness and lay the large loop between the two nails on the poles in such a manner that this large loop forms a triangle. The string between the two poles should be as taut as possible to facilitate easy pickup.

Cement the wing to the Fuselage by sliding the leading edge under the top fuselage-covering "shelf". Apply cement also around the exterior of this joint.

The stabilizer is constructed in identical fashion as was described for the wing except that the structure is made in one unit from tip to tip. Cement the completed stabilizer to the fuselage.

The full-scale glider is towed aloft with the two wheels in place; these are dropped when the craft is a few feet off the ground. For this reason our model does not carry the wheels shown on the plans. The landing skids can be added at this time. These should be assembled first and then fitted to the model in a very secure manner. Use plenty of cement. Cut the wing struts from balsa sheet and cement them to the fuselage and wing. Attach the towhooks as shown and cement well.

The troop gliders are colored all olive drab. We brushed on one coat of this color dope onto the entire model. Insignia is a standard decal, while the windows and control outlines are cut from white "Trim-Film", described previously.

As in all flying-model airplanes, the craft must balance correctly before any attempt is made to fly it. This model will require a slight amount of weight in the nose, as did our model in Chapter Three. Cut a small hatch

 in the nose bottom and cement lead weight or solder to the inside until the craft balances as shown in the plan. Hand gliding must precede any flight attempts; follow the procedure outlined in Chapter Three for free-flying models.

"The Lensman"" Photo

Our "Waco Troop Carrying Glider" can be utilized for glider pickup stunts. The music wire harness extending above the nose is used for this interesting activity and must be rigidly fastened.   Instructions are described in Chapter Six.

Fuselage and tail are sheet balsa while the wing utilizes a very simple structure.

Test flights can be conducted with a forty-foot-long tow-line of carpet thread or light-weight nylon. Fasten a wire loop at one end of this line and tie a piece of tissue eight inches from this loop as the plans illustrate. Attach the wire loop onto the belly hook, using the rear hook for dead calm weather and the forward hook for windy weather. The model is towed into the wind in such a fashion that the craft will tend to turn directly into the wind. For example, should the model be set for a left turn, it must be towed in such a manner that the wind is blowing on the model's forward left side. The assistant holds the model at shoulder height and releases the craft upon the flier's signal. A slow walk is all that is required to cause the model to climb. If the plane tends to turn to the right or left during the tow, quickly walk to the opposite side of the turn. When the model is almost overhead, slow your pace and the tissue will cause the loop to disengage from the towhook. Observe the flight path and correct it as described in Chapter Three. A one-hundred-foot towline can be used once the craft is well adjusted.

It will be found that extreme realism is enjoyed with this scale glider. The view from the ground as these craft slowly circle, ever so silently, makes one almost expect fully armed soldiers to disembark when the glider slides to a stop! Additional realism and stunt-contest winning ability can be achieved by utilizing a ground pickup system; use a medium-size control-line model as the pickup plane. This will be described in Chapter Six when, it is assumed, the reader will have accumulated enough building and flying experience. Whether or not the reader attempts glider pickup, a powerless airplane, especially a scale replica, is an interesting addition to any model collection.

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