Extra 300S 60 (oz10977)

About this Plan

Extra 300S 60. Radio control sport-scale model, for 60 power.

Discontinued kit from Great Planes.

Quote: "Congratulations on purchasing the Great Planes Extra 300S. We've selected the 'S' because we feel it looks the best and it is truly meant to perform aerobatics. Among a few versions of the Extra 300 out there, another popular one is the 'L' which accommodates two passengers - one student and one flight instructor.

The Extra is a rather 'square shaped' airplane with well defined lines. Coincidentally, this makes it exceptionally easy to build and cover - especially for a semi-scale sport model. Framing the model is very straightforward as most of the structure features interlocking balsa and lite-ply. The turtle deck sheeting may look a little intimidating but in actuality it is quite easy to apply if you follow the instructions and use the template provided to cut the sheeting.

Flying the Extra 300S is a thrilling experience - as it should be for such an aerobatic model! It doesn't take much elevator or aileron throw to put the Extra through its paces. When you have a feel for your Extra 300S, the throws can be increased to high rates (illustrated in the instructions) to really showcase the aerobatic potential. The Extra performs surprisingly well on a ball bearinged, Schnuerle ported .61, and even better with a .91 4-stroke, but seasoned experts will surely want to get the most out of the Extra by strapping on a .91 2-stroke or a 1.20 4-stroke.

We hope you enjoy building and flying your Great Planes Extra 300S as much as we did flying the prototypes.

Precautions. 1. Build the model according to the plans and instructions. Do not alter or modify the model, as doing so may result in an unsafe or unflyable model. In a few cases the plans and instructions may differ slightly from the photos. In those instances the plans and written instructions should be considered as correct..."

The manual is available for download from the Great Planes site at http://greatplanes.com/manuals/discontinued.php

Direct submission to Outerzone.

Note CAD file is thanks to AlanSinclair.

Quote: "Hello... the Great Planes Extra 300s plans were extracted and converted from the instruction manual I did not redraw them, though they were re-scaled to the correct size. The DXF file does includes all the formers and ribs, which I did have to redraw... Thank you, Alan."

Update 11/12/2023: Added kit review from RCM, April 2000, thanks to RFJ.

Quote: "RCM Product Review: Extra 300S 60. By Jack J Joseph.

The giant planes flown by IMAC competitors aren't my cup of tea. I couldn't get a wing in my car, let alone the fuselage, so when the Great Planes Model Manufacturing Company announced their new 60 size Extra 300S in October, 1998, it seemed an answer to my dilemma. I ordered one.

The kit came in a brightly illustrated box that measured 30 x 10.5 x 6 in. The small metal and some wood parts were bagged and the canopy was wrapped in tissue. I removed all of the items and, to make each part easy to identify, I used a thin point pen to ink the stamped parts numbers on each of the sheets.

Construction: The rolled plans were on two 36 x 46 in sheets and a 48-page instruction manual accompanied the plans. The manual contained 183 pictures and 18 sketches, plus a list of required accessories and tools, and a discussion on engine selection. The center section of the manual was an 8.5 x 17 in reproduction of the large plans which was extremely helpful, as it kept me from having to unroll the plans to identify a part and its location while I went over the instruction manual and, later, during assembly when the parts being assembled covered the plans.

The quality of the parts was first class. The die-cut balsa and plywood parts were easily removed from the sheets and only required a fast touch of sandpaper to remove any burrs.

I used a variety of adhesives: Pacer Zap and Slo-Zap, Great Planes Pro Wood Glue and Frank's Hobby House 5 and 30-minute epoxy. All of the nuts and bolts were secured with Loctite 242 Thread Locker.

The instructions in the manual were easy to follow; just do as instructed, check off each step as it is completed, and 'voila' you have a great model.

The tail feathers were framed with 5/16 balsa. The stabilizer and fin were then sheeted with 1/16 balsa. The elevators and rudder were open frames.

Since hardwood wing spars are seldom straight as an arrow, I was pleased to find instructions on how to install the upper and lower spars so any warps would counteract each other and result in a straight beam.

The wing was standard built-up construction. Although the 1/16 balsa sheeting surprised me since most planes of this size I had encountered used 3/32 or 1/8 in. No doubt this is a way to save weight..."

Supplementary file notes

Kit manual, 50 pages complete.
Review.
Vector plan (extracted from manual, unscaled).

CAD file

This plan is available for download in CAD format.

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