D-KGRU

D-KGRU is a Fournier RF-4, a single-engine piston aircraft. SkyMeter has tracked 22 flights totalling 10 hours of airtime via ADS-B. Service window in our records spans 230 days. The Fournier RF-4 has a maximum takeoff weight of 1,213 lb, light wake category.

About the Fournier RF-4

The Fournier RF-4 is a French two-seat motorglider designed by René Fournier in the early 1970s, blending the soaring efficiency of a sailplane with the convenience of self-launch capability. Built primarily by Sportavia-Pützer in Germany under license, the RF-4 features a high-aspect-ratio wing spanning 17 meters and a modest 40-horsepower Limbach engine mounted in the nose. With a glide ratio exceeding 27:1 when the engine is shut down and the propeller feathered, it occupies a unique niche between pure gliders and conventional light aircraft—pilots can climb under power to find thermals, then soar silently for hours before restarting for the return to base.

The type became popular in European gliding clubs during the 1970s and 1980s as an economical trainer and cross-country platform, offering genuine sailplane performance without the logistical burden of towplanes or winches. Its docile handling, excellent visibility from the tandem cockpit, and rugged construction made it a favorite for introducing pilots to soaring, though production ended in the early 1980s as composite motorgliders began to dominate the market. Today the RF-4 remains a cherished classic among vintage motorglider enthusiasts, particularly in Germany and Scandinavia where many examples continue to fly.

SkyMeter has tracked flights across airframes and operators, covering routes.