VanGrunsven RV-5



RV-5 is a one-off proof-of-concept prototype airplane designed by Richard VanGrunsven. Although the designation is the 5th in the Van's Aircraft "RV" series, the RV-5 was never intended as a production aircraft but as a project for VanGrunsven and fellow members of his Experimental Aircraft Association (EAA) chapter.

The RV-5 has a single seat, a shoulder-mounted wing, full-span flaperons, fixed landing gear in a conventional configuration, and all-metal structure – mostly 0.016 in aluminum. The airplane originally flew in the summer of 1976 with a 30 hp half-VW engine, and was later re-engined with a 41 hp Rotax 447. The straight, untapered wings use a flat-bottomed NACA 4414 airfoil. The canopy was initially designed and fabricated for the RV-2.

For storage and ground transportation, the front spar can be disconnected from the fuselage, then the "scissor-wing" can pivot 90 degrees about a bolt on the rear spar, at which point the flat bottom of one wing will rest on the flat upper surface of the fuselage. This is similar to the storage configuration later used on the Bell Boeing V-22 Osprey.

The airplane was designed in light of the 1970s energy crisis, to explore how much performance could be achieved with the use of an engine with very low fuel burn. A member of EAA Chapter 105 developed the first "half VW" airplane engine - i.e. an engine that uses two of the four cylinders of a Volkswagen air-cooled engine – and wanted to test it on a light airframe. Richard VanGrunsven, a member of Chapter 105, designed the airplane and led the chapter in its construction and testing from 1975 to 1976.

In 1984, Richard's brother Jerry VanGrunsven borrowed the airplane and took it to his airpark home near Seattle. Most of the subsequent hours on the airplane were flown by Jerry and his two sons.

From 2017 to 2019, the RV-5 was restored and then displayed at EAA AirVenture Oshkosh. It is currently on display, hanging from the ceiling beams of the hangar that houses Van's Aircraft's factory-demo fleet of airplanes.

Specifications

 * 75%-power cruise speed: over 100 mph
 * Fuel consumption, economy cruise: 3 gph