Osprey 900 (oz8526)

About this Plan

Osprey 900. Radio control sailplane.

Quote: "Can the new American balsa-framed FAI models beat the European 'glass smoothies'? Here is a sensational scratch-built that has been blowing everyone off the courses at our major meets.

Osprey 900, by Ray Hayes.

IT IS one thing to build a sailplane from a manufactured kit, but quite another to design and build one from scratch. Scratch building can be defined by those ominous words from your boss: What are you working on so hard? He peers into your calculator and writing pad filled with strange (to him) numbers and platform scribblings and asks: Why are you dividing everything by 144? Scratch building is also cutting your own wing ribs, learning from your mistakes, and ignoring negative comments about your dream ship. Needless to say, scratch building, when successful, can be the most satisfying aspect of modeling. I recommend it to anyone who is looking for a way to release their creative moods.

The Osprey 900 was designed to win the FAI team selection program with only 100 inches of wing span. This is not likely to happen with any consistency, so the effort was questionable from the start. As a matter of fact, there were only three Standard Class airplanes that finished in the top twenty. The 900 did have the fastest total time in the speed event. It turned 13.6 -14.0 - 14.4, in that order. That was the only claim to fame I accomplished at Pensacola. The wing loading is 8.65 ounces empty and I flew the speed task at 13.14 ounces. Interestingly, during the second and third day of competition the ship became more subject to tip stall and was flying slower and required rudder trim. As a result, I kept adding nose weight.

Dropping from first place at the end of round three to twelfth overall in a six-round contest gave me a lot to think about during the long drive home.
One of the suspicions I developed was I may have lost my washout. All right, maybe my cool, too! The wings were built without washout and fully sheeted, but I managed to warp the structure into washout during August. I must confess that I had trouble keeping the washout and I didn't remember to check it during the contest. Sure enough, the left wing was flat and the right panel was off just a bit. That's living and learning.

The maiden flight occurred during January 1978 on Ma Maria Island in Florida and its first speed run was late April back home in Indiana. The ship was at base 'B' midway through the turn when the nylon center box exploded, allowing the wings to conform to your average V in anyone's alphabet. I heard the crash, but fortunately I didn't see it. There may have been the width of my daughter's eyelash between Mono-Kote and turf.

I narrowly qualified in the Brandon, Florida, May quarter-final. I used an Aquila that had been hanging out in my garage since 1976. I could have flown in the Detroit quarter-final, but if you were in Florida during January you can understand why my family wanted to return in May. During this second trip to Florida, the Osprey was in the hospital recuperating and new center boxes were being milled from aluminum. The nylon center box is not strong enough for FAI speed tasks..."

Direct submission to Outerzone.

Supplementary file notes

Article pages, thanks to RFJ.

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