Ultra Sport 40 (oz14057)

About this Plan

Ultra Sport. Radio control sport aerobatic model.

Discontinued kit from Great Planes.

Quote: "Introduction: Congratulations! Thank you for purchasing the Great Planes Ultra Sport 40! Jim Feldmann's original design Ultra Sport 60 (oz6177) was featured as a construction article in the August, 1989 issue of RC Modeler magazine, and has been hailed by many as the best sport flying airplane ever. The design starts with the legendary Kaos (oz6251) wing planform, and features modem styling and state-of-the-art construction techniques. The result is an ultra-stable, ultra-smooth flying airplane that does what you want it to, no more and no less.

The Ultra Sport 40 is easy to build, totally predictable, smooth-flying and has very docile stall characteristics, making it the ultimate sport airplane for the modeler who wants to fly with a higher degree of precision. Because it naturally tracks through maneuvers better than other sport airplanes, you'll fly better when you're flying an Ultra Sport 40.

This is not a beginner's airplane! While the Ultra Sport 40 is easy to build and flies great, we must discourage you from selecting this kit as your first R/C airplane. It is fast, highly maneuverable, and lacks the self-recovery characteristics of a good basic trainer such as the Great Planes PT Series airplanes. On the other hand, if you have already learned the basics of R/C flying and you are able to safely handle an aileron trainer airplane such as the Great Planes Trainer Series or Big Stick Series airplanes, the Ultra Sport 40 is an excellent choice.

Decisions you must make now: Engine and Mount Selection: The recommended engine size range is as follows:

.40 - .46 cubic inch displacement 2-cycle
.60 - .70 cubic inch displacement 4-cycle

NOTE: Although not included in the above engine size range, the OS MAX 48 SURPASS also provides sufficient power to fly this airplane.

The engine you select will determine how you build the fuselage, so it is important that you have the engine close at hand while building. This kit includes a Great Planes MM40 engine mount that fits most .40 - .45 (2-cycle)engines (only slight modification of this mount is required to mount the OS40SF and OS46SF). If you are installing an OS48 SURPASS (4-cycle), you may purchase a Great Planes MM60 mount. If you are planning to install theOS70 SURPASS (4-cycle), you may purchase the Great Planes MM60L mount. If you prefer, you may purchase a custom engine mount for your engine, or you may choose to install shockabsorbing rubber-cushioned mounts.

NOTE: If you choose to power your Ultra Sport 40 with a 4-cycle engine, keep in mind that the RPM of your engine will be considerably less than that of a 2-cycle engine; therefore, you should select a higher pitch propeller to keep the speed and overall performance roughly equivalent to that of a 2-cycle engine. For example, a 10x6 or 10x7 prop would be used with a .40 (2-cycle) engine; but an 11x9 or 10x10 prop may be the best choices for a 4-cycle engine.

Landing Gear Configuration: The Ultra Sport 40 may be built with either a taildragger or tricycle landing gear configuration, and a retractable main gear may be installed if you want to really clean up this airplane for ultra-smooth and precise aerobatics. There is not, however, room for a nose gear retract; therefore, if you want retracts, you'll have to use the taildragger configuration..."

Direct submission to Outerzone.

Supplementary file notes

Instructions. 48 pages.

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