Osprey 900 (oz8526)

 

Osprey 900 - plan thumbnail image

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.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction

Osprey 900 - completed model photo

Datafile:
  • (oz8526)
    Osprey 900
    by Ray Hayes
    from Model Aviation
    January 1980 
    100in span
    Tags: Glider R/C
    all formers complete :)
    got article :)
  • Submitted: 07/03/2017
    Filesize: 549KB
    Format: • PDFbitmap
    Credit*: Circlip

Do you have a photo you'd like to submit for this page? Then email admin@outerzone.co.uk

User comments

No comments yet for this plan. Got something to say about this one?
Add a comment

 

 
 

Download File(s):
 

Notes

* Credit field

The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.

Scaling

This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.

 

Terms of Use

© Outerzone, 2011-2019.

All content is free to download for personal use.

For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.

Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.