Eclipse (oz1832)

About this Plan

Eclipse. 180in RC Duration Sailplane, pod & boom V-tail, Hal Cover, Oct 1974 AAM.

Quote: "It casts a big shadow - with 16 feet of wing it should! Designed specifically for extended duration, the Eclipse will ride thermals almost forever.

Why a glider with a 180 in span and the name Eclipse? You will understand the first time it flies over your head with its gracefulness and beauty. When it lands the size becomes very apparent, and you might even expect a pilot to climb out looking for his glider trailer.

In comparing the performance of the Eclipse to a smaller version, interesting performance variations appeared. First it flew in much higher winds than the smaller one, even though both had an 8 oz/sq ft wing loading. Also, still air flight times were as much as 50% better with the larger model. Probably the larger glider's only weakness is that it is hard to pick up thermals at low altitude. The relatively large tail and long tail moment contribute to its extremely stable flight characteristics.

In calm weather, flights of up to ten minutes have been made without aid of the controls - in other words, free flight - that includes the launch, too! If the plane is allowed to fly straight, it will turn into lift by itself and stay in lift; so let it find the lift for you. The spoilers are just effective enough to allow a good controlled sink, with only up trim needed for proper attitude. This makes spot landings a cinch.

The spoilers proved their worth on one flight where the plane rode a ther-mal until it disappeared in the clouds. At this point, the spoilers were opened and a large circle set in the controls. Without further action, the plane came down safely - but it took half an hour! This plane is big, and therefore can't be treated like a small plywood and foam glider. If it gets way up in a thermal, use the spoilers and up trim, don't dive it or spiral it in because the plane picks up speed fast and it is not indestructible.

Locating a fiberglass tailboom for the Eclipse may pose a problem for prospective builders. However, there are several approaches one can take. First, as the author did, contact your local sporting goods store and have them recommend a fishing pole manufacturer from whom you can make a selection. If no manufacturer is readily available, perhaps the sporting goods store will order one for you. The fiberglass rod should be about seven-nine ounces in weight, eight to nine feet long and have a diameter of approximately 1-1/4in at the large end.

Building Tips: Always use spruce wherever shown - don't substitute balsa. Web all areas indicated with hard balsa. The wing and stab structures require a web for necessary structural properties. The wing center section needs the 1/16 piano wire and fiberglass cloth covering on the trailing edge; it is also recommended that the center section leading edge and tip dihedral leading edge and trailing edge joints be fiber-glassed..."

Update 12/01:2017 added article, thanks to RFJ.

Supplementary file notes

Article.

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