The original Kaos was first published in February 1970. This was a derivation of the Sun Fli series of airplanes. If you look at the Kaos and Sun Fli airplanes, you can see the "family" resemblance.

The Super Kaos plan was published in 1973, and was Joe Bridi's response to the addition of retractable landing gear in Pattern aircraft. The lines are also a bit different from the Kaos because he was also designing the model to better fly the pattern as it had changed over the past few years.

The Sun Fli airplanes, the Kaos, and the Super Kaos were all intended to be powered with .61-size (10 ccm) engines. I had a Kaos with the first O.S. Max .60 FSR in the area. I later had a Super Kaos with the Webra Speed .61 engine in it. Like today, people looked for power.

The .40-sized version of the Super Kaos came out as the Super Kaos, Jr. in plan form, and was called the Super Kaos .40 in the kit form.

The current version, the Tower Hobbies Kaos .40, is basically the Super Kaos .40 design.

The Ultra Sport series of airplanes are basically the Kaos design with a turtledeck-type fuselage. The wing airfoil and moments are very similar, which account for them having such nice handling, a feature the Kaos-series was well known for.