Description

The Vapor is a high performance aircraft in a small size.  Designed for the O.S. 25 SF or FX engines, it has an estimated top level speed of about 70 mph (higher in a dive, of course), which looks fast for an airplane this size.  With the recommended 8X8 propeller giving high maneuver- entry speeds, coupled with low overall airframe drag, vertical performance is impressive, although not unlimited.  The airplane has near-neutral stability in pitch and roll - it will pretty much go where you point it with no natural inclination to return itself to straight-and-level flight.  With its nearly full-span ailerons, the Vapor’s roll rate is in the neighborhood of 1400 degrees per second (about 4 rolls per second).  Because of its speed and neutral stability, I’d recommend gaining some experience with higher-performance models before attempting to fly a Vapor.  If you’re already at that stage, a Vapor will prove to be a fun, fast, nimble little airplane. One of the Vapor prototypes was also built and flown with an O.S. 32 SX engine with an in-cowl muffler, turning an APC 9X8 prop (photos above and right).  This combination flies well and does give the airplane unlimited vertical, but with reduced flight times (5-6 minutes on 4 oz of fuel, as compared to about 10 minutes when powered by a .25 FX). The Vapor is a one-piece airplane - the wings do not detach.  This was done to save a little weight while still keeping the airframe strong enough to withstand the aerobatics the airplane was designed for.  However, with a wingspan of only 42 inches, it’s still pretty easy to transport.  The canopy is removable for access to the radio bay.  All-up flying weight is 3.5 to 4 lbs with four ounces of fuel. Vapor

Vapor