1992 RANS S-9 Chaos Viper
A barn find with an airshow past and a serious engine upgrade under the cowl. We're bringing this one back to life — follow along as the project comes together.
A Purpose-Built Aerobat
Designer Randy Schlitter drew the RANS S-9 Chaos in 1986 with one goal in mind: a light, welded steel-tube-and-fabric single-seater that could hold its own in sportsman aerobatic competition — quick on the controls, cheap to fly, and built to take a beating. This "Viper" variant carries the upgraded canopy and cowl styling RANS introduced on later kits.
Our RANS S-9, N218ES, is one of 215 known completed aircraft and was built in 1992 by Paul "The Great" Ordini. It's a true performance aircraft capable of Sportsman Class or Advanced aerobatics while still being comfortable on a cross-country flight. With a stall speed of 33 mph, it's easy to land and can operate from a strip under 600 feet.
Experimental / Amateur-Built — S-9 aircraft are hand-assembled by their builders.
Official three-view drawing, RANS Aircraft, Hays, Kansas
Rotax 670
There are multiple versions of the S-9 kit, built around Rotax and Hirth engines ranging from 64 hp up to 100 hp. This one is running a Rotax 670, rated at 90 horsepower. Bolted to an airframe that only weighs 320 pounds empty, that's a serious power-to-weight jump, and it's the kind of upgrade that turns a fun sport plane into something with real teeth — full write-up coming as the project moves along.
An Airshow Past
This aircraft was built and flown by Paul "The Great Ordini" Ordini — FAA registry lists him as the builder — an airshow performer for more than fifteen years who flew at Sun 'n Fun, the Sussex Airshow, and venues across the country before his passing in 2018. The sponsor decals still riding on the airframe back that up — this plane has demonstrated performance.