Binder Cp-301s Smaragd

Single Piston

The Binder CP-301S Smaragd is a German-built single-seat motorglider that bridges the gap between pure sailplanes and light aircraft. Manufactured by Binder Motorenbau, the Smaragd (German for "emerald") features a retractable piston engine that can be extended for self-launch and climb, then stowed to restore the aircraft's clean glider profile for soaring flight. This dual capability allows pilots to depart from conventional airports, climb to altitude under power, and then shut down the engine to exploit thermals and ridge lift like a pure glider — all without requiring a towplane or winch launch. With a maximum takeoff weight of just 650 kilograms (1,433 pounds) and a wingspan optimized for efficient soaring, the CP-301S represents a niche category of self-launching sailplanes popular in European general aviation. Its retractable powerplant and lightweight construction deliver respectable climb performance while preserving the low sink rates essential for cross-country soaring. SkyMeter has tracked 2 flights across 1 airframes and 1 operators, with distinct routes observed.