Rearwin Sportster 9000L (oz1296)

About this Plan

Rearwin Sportster 9000L. Single channel radio control scale gas model for .049 power.

Quote: "Rearwin Sportster 9000L. Single channel or free-flight scale of a famous sport plane of the middle and late 1930s. 1/2A engine and small single channel receiver with escapement, or a motorized actuator, are all that is necessary for well flying scale machine. By ME Salvay and Don Alix.

Now for a few details on the Model 9000L Sportster. It was a steel tube, wood, and fabric plane. Two-place tandem seating was provided with baggage behind the rear seat. Unique was its all ball-bearing control system and oil-spring shock absorbers. The 9000L used the 90 hp Ken-Royce engine and cruised about 110 mph with a top of 123 mph. It grossed at 1460 pounds and compared to today's standards, the performance was pretty good.

Wingspan was 35 feet and length of about 22 feet plus. The plane was relatively tall, being almost 7 feet. The wing airfoil was an M6 reflex, which was popular in the early 30's. Special equipment was obtainable to permit night-flying, radios, engine starters, etc. Many non flying school planes came equipped with wheel pants.

Our model has been constructed without the wheel pants, but the NACA speed ring, that was so popular on most of the deluxe Sportsters.

As for the model, it was originally built as a single channel R/C plane, and used the Citizen-Ship LT-3 receiver. After a number of flights in this manner, the author removed the equipment and flew the model as a free-flight; and for one reason only. Due to the congestion at the Los Angeles RC field at Sepulveda basin, you couldn't have a regen set around. So in order to enjoy my main activity, which was scale flying, I tossed the towel in on the small RC equipment.

The model is a beautiful stable flyer, weighing 20 oz. The Cox .049 engine with an 8x4 prop gives surprisingly excellent flight, although insufficient power limits take-offs. As a result, all flying is done hand-launched. The adjustable stabilizer permits precise trim when used with a bit of nose ballast, and a flat glide and slow climb produces almost scale-like flying.

When flying as RC, the rudder, being full scale, must be very restricted in travel, say 1/16 to each side or the rolling effects are quite excessive. Since this author goes for scale rudder appearance and scale approach to rudder control systems, this is a critical point. Some builders may prefer to have a small tab only for a rudder and the conventional torque tube control.

The model is very ruggedly built and employs only one rubber band externally. This author has aversion to rubber bands holding scale models together.

Construction. Cut 26 ribs with spar notches from hard 1/16 balsa sheet. Cut four ribs from 1/16 birch ply, but include leading and trailing edge contours and leave out spar notches. Instead, drill 1/16 diameter hole for wing wire plug-ins. Two ribs will be used for wings and two for fuselage..."

Update 7/1/2024: Replaced this plan with a clearer version, now at 600 dpi, thanks to dfritzke.

Direct submission to Outerzone.

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