Gus (oz6017)

About this Plan

Gus. Slope soarer model. RCM March 1970. Model # pl-419. Designed by Willie Richards.

Quote: "Gus. This thoroughly tested glider is the answer for light air and zero sink conditions. A magnificent performer. It is as easy to fly as it is to build.

There is a condition which is not very common among model sailplanes that is called zero sink. This condition is often overlooked by most slope soarers and very few designers & flyers enjoy it's benefits. This is when lift is equal to the pull of gravity either in thermal or almost nil wind conditions on a slope.

Dr Rolph McPherson, noted designer and glider flyer, once stated that these conditions provided the best time to soar. GUS was designed to need 10 to 20 knots of wind blowing on a slope for adequate lift. Several visits to our local site showed that I needed a sailplane that would fly as well in weak as in strong lift.

Subsequently, I began working on a wing loading and airfoil combination, that, along with scale appearance, would give a clean design. Gus would have very good penetration ability without the loss of performance. Several wings were used employing different airfoils: flat bottoms, symetrical and undercambered. The undercamber proved to be the better airfoil for my purpose of having good lift at low speed - even down to about two mph of wind on the hill. There were even times when flying the GUS that we thought we were breaking the sacred laws of nature. We saw many fine high performance sailplanes setting on the ground while we enjoyed this condition which is known as zero sink. All things had to work and carry their own in the final design - even the fuselage is aerodynamically designed to carry some of its weight. In some comparison flights the performance is along with that of the famous Little-T, Barnacle, and Malibu. These are some of the standard class sailplanes which have fine performance even down to winds below 5 mph when the weight is kept below 32 ounces. The weight of the GUS was a flat 21 oz ready to fly!

Along with scale-like appearance we wanted our ship to look, as much as possible, like the real sailplanes. Several modifications have been made from the original GUS to bring its appearance to these standards. With cockpit details, such as instrument panel, pilot and clear plastic canopy GUS becomes a real sharp looking sailplane.

This model was designed as a thermal as well as a slope soarer to meet the standard class sailplane requirements. We hope that this will some day become a class where such sailplanes, as mentioned in this article, and many others that are under the 100 in mark, may compete against each other in local and open competition.

GUS has also proven to be a fine sailplane in the hands of the absolute novice. This was my first sailplane, not only to design, but to have successfully flown. (It has taken 12 months of building & flying this design to give us our present version.) Gus has, also been flown rudder only
showing very little loss of performance without the aid of elevator. I have never flown it with any of the Galloping Ghost or pulse rudder systems but I am sure it is docile enough for them. For best performance, keep the weight under 25 oz ready to fly.

Construction: Wing. The wing is simple and straight forward in construction. Cut out all ribs from medium hard quarter grain stock of 1/16 sheet balsa. The leading edge is medium hard balsa, with spruce spars and balsa trailing edge. The wing is jigged to get the true airfoil shape as shown on plans..."

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