Sierra Trainer (oz12139)


Sierra Trainer (oz12139) by Bill Evans 1986 - plan thumbnail

About this Plan

Sierra Trainer. Radio control tailless trainer.

Quote: "Sierra Trainer, by Bill Evans. This 20-powered R/C trainer will grow as your ability to fly it increases. With elevons, no elevator is needed. It can be flown with three or four-channel equipment. Foam wings are available.

You may wonder, after the many of the Simitar series, from the Simitar XV, the Simitar 540, the twins, the X-Wings, the anhederal Desperado, and the more recent Tracers, why now a trainer?

The Sierra Trainer is not another ho-hum trainer. It's a Twenty-first Century craft of the Simitar Series, with a heritage of more than thirty previous designs over the past fifteen years. Since it has never been my lot to reinvent the wheel, you will find that the Sierra Trainer has been designed, built, and will fly like all ships should have been.

Backing up a bit, the first part of the name was easy. It was designed, built, and first flown in the Sierras just sixty miles north of Mt Whitney, the highest peak in the continental US. The trainer part includes much, much more. The high wing and the box fuse makes it look like a trainer; and it flies like a trainer, but better than any other.

The first advantage is the absolute no-stall characteristic. There is no tip stall on a premature takeoff or when trying to stretch the glide to make the runway. Second is the natural ability of the Sierra Trainer to remain in any mode that you put it in. Touch a bit of right aileron, let off, and the ship will hold itself in a right turn without any tendency to wind down. Or touch a little up, let off, and the craft will climb and continue to climb until it reaches max for power and then it will gently level off. The hands-off cruise is truly remarkable.

Another advantage is that the ship will grow with you; it will teach you to fly and as your flying skill grows, it will perform with ease any maneuver you ask. So, no need to get another ship to learn to do skilled aerobatics, the Sierra Trainer will do it all.

In a way, the Sierra Trainer is the high-wing version of my Simitar Slow Motion. I am sure that you read Bill Winter's 'Just For The Fun Of It,' in which Bill has described at length the advantages of the Slow Motion. When I told Winter that I had something easier to fly than the Slo Mo, the Sierra Trainer, he said: 'Impossible'.

Ease of construction is also on the plus side. In my time I've built many kits, so I know what makes for easy, no fuss building..."

Sierra Trainer, Model Builder, December 1986.

Direct submission to Outerzone.

Update 04/05/2020: Replaced this plan with a clearer copy, thanks to MB 2020.

Update 29/07/2020: Added vectorPDF and CAD (dxf and dwg) versions of this plan, thanks to Valeria367.

Quote: "Hi, Steve and Mary. How are you? I hope both are really fine. Some weeks ago you published the plan of one of my favorites Bill Evans' designs: The Sierra Trainer (oz121399), one plan that I was looking for for years. Now that I have the plan, thanks to you, I've made one of my usuals CAD redraws, and I want to share it with you. As usual, I send you it in vector PDF, plus both vector CAD formats: DWG and DXF. Greetings, from your friend,"

Supplementary file notes

Article pages, thanks to RFJ.
Previous scan version.
VectorPDF plan tracing.

CAD file

This plan is available for download in CAD format.


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Sierra Trainer (oz12139) by Bill Evans 1986 - model pic

  • (oz12139)
    Sierra Trainer
    by Bill Evans
    from Model Builder
    December 1986 
    60in span
    IC R/C
    clean :)
    all formers complete :)
    got article :)
  • Submitted: 18/02/2020
    Filesize: 644KB
    Format: • PDFbitmap • PDFvector • CADfile
    Credit*: Circlip, RFJ, MB2020, Valeria367
    Downloads: 860

Sierra Trainer (oz12139) by Bill Evans 1986 - pic 003.jpg

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User comments

That would be fun to add a horizontal stab with velcro. Then have it go tearing out of the runup stand.
Tom Solinski - 30/04/2020
'In a way, the Sierra Trainer is the high-wing version of my Simitar Slow Motion' - That's bad luck! OZ has six Simitar incarnations but the SM isn't one of them. Looking for it in RCG I saw a Simitar Psycobipe instead and that was when I fell off my walking frame :-)
Miguel - 01/05/2020
Simitar Slow Motion was published in the January 1987 issue of Model Aviation.
RFJ - 01/05/2020
With your graceful input I was able to locate that issue at
Thank you very much, sir, and to AMA as well.
Miguel - 01/05/2020
Coincidentaly, I'm building this one right now with my daughter. She said she wants to learn to build and fly : ) and it was the only one of all the project I have in queue that is at least somewhat adequate for a novice. Imagine our surprise when we saw it posted in OZ. Guess we'll submit some photos when its done.
RC Yeager - 03/05/2020
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Download File(s):
  • Sierra Trainer (oz12139)
  • Plan File Filesize: 644KB Filename: Sierra_Trainer_oz12139.pdf
  • Supplement Filesize: 1873KB Filename: Sierra_Trainer_oz12139_article.pdf
  • Supplement Filesize: 335KB Filename: Sierra_Trainer_oz12139_previous.pdf
  • Supplement Filesize: 715KB Filename: Sierra_Trainer_oz12139_vector.pdf
  • CAD Zip Filesize: 165KB Filename:
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