Great Planes Ultra Sport: The Classic Sport Plane, Versions and Specs
The Ultra Sport is a classic Great Planes low-wing sport aerobatic plane, sold over the years as balsa kits and later as an ARF. The Ultra Sport 40 has a 55-inch span and suits .40-size engines; the Ultra Sport 40 Plus spans 58.5 inches with a symmetrical NACA 63014 airfoil for .40–.52 two-strokes or .52–.70 four-strokes; and the Ultra Sport 60 spans 61.5 inches for .60–.65 two-strokes or .70–.91 four-strokes. The kits are discontinued, so most are found used or built from plans, and an Ultrasport .46/EP ARF was also sold.
By Kyle HilsonUpdated: October 20263 min read
Versions
| Version | Span | Wing area | Weight | Engine |
|---|---|---|---|---|
| Ultra Sport 40 | 55 in | 566 sq in | about 6 lb | .40 class |
| Ultra Sport 40 Plus | 58.5 in | 595 sq in | 5.3–5.7 lb | .40–.52 2-stroke / .52–.70 4-stroke |
| Ultra Sport 60 | 61.5 in | 707 sq in | about 7 lb | .60–.65 2-stroke / .70–.91 4-stroke |
| Ultrasport .46/EP ARF | See listing | Glow or electric |
From Great Planes documentation and dealer listings; kits are discontinued.
Why it’s well loved
The Ultra Sport became a favourite second plane: after a high-wing trainer, it taught generations of pilots to fly aerobatics. Its symmetrical airfoil flies equally well upright and inverted, and it handles loops, rolls, snaps and spins, yet slows down for gentle landings. That balance of performance and forgiveness is why many pilots still build or rebuild them.
Building from a kit or plans
Original kits were balsa and plywood with detailed manuals. Plans are available from plan archives for those who want to scratch-build. Covering with iron-on film, fitting a glow engine (or an electric conversion) and standard servos completes the plane. Engine choices like OS two- and four-strokes are covered in OS model airplane engines.
Electric conversion
Many builders now convert the Ultra Sport to electric with an outrunner motor sized for the airframe weight, a 4S–6S LiPo and a suitable ESC. Plan the battery position for the correct CG and add cooling airflow through the cowl.
Flying tips
- Set the CG as the manual states, then refine with dive tests.
- Start with low rates and some expo.
- Practise rolls and loops at a safe height.
- Add rudder in turns for coordinated flight.
- Land with a little power; it glides well and lands smoothly.
Buying used
- Check the firewall and engine mounts for oil soaking and cracks.
- Look for loose covering and warps.
- Inspect the landing gear mounts.
- Ask about the engine’s history.
- Check control surfaces for hinge play.
Modern alternatives
Several current ARF makers offer similar low-wing sport planes in balsa or foam, often with electric power. Classic ARF makers are discussed in World Models RC planes.
Getting the trim right
Because the Ultra Sport flies equally well inverted, small trim errors show up clearly. Check that the wing is straight and the control surfaces are neutral, then trim in calm air. A dive test helps fine-tune the CG; knife-edge passes show whether rudder mixing is needed. A well-trimmed Ultra Sport rolls axially and tracks straight through loops.
FAQ
Is the Great Planes Ultra Sport still sold?
The kits are discontinued; used planes and plans are available.
What engine for an Ultra Sport 40?
A .40-size two-stroke; the 40 Plus takes up to .52 two-stroke or .70 four-stroke.
Is it good for beginners?
It’s a second plane after a trainer.
Can I make it electric?
Yes, with a suitable outrunner and LiPo.
More on this topic: the complete RC Airplanes guide covers the basics behind this article.
About 20 years in RC. Mostly boats in the NAVIGA Mini Eco Expert class, with many self-made parts; also a King Motor Baja 5B, a home-built electric plane, home-built nitro planes he has flown, and an RC helicopter. More about SwellRC
