Gnome Omega

The Gnome 7 Omega (commonly called the Gnome 50 hp) is a French seven-cylinder, air-cooled aero engine produced by Gnome et Rhône. It was shown at the Paris Aero Salon held in December 1908 and was first flown in 1909. It was the world's first aviation rotary engine produced in quantity. Its introduction revolutionized the aviation industry and it was used by many early aircraft. It produced 37 kW (50 hp) from its 8 L (490 cu in) engine capacity. A Gnome Omega engine powers the 1912 Blackburn Monoplane, owned and operated by the Shuttleworth Collection, the oldest known airworthy British-designed aeroplane worldwide. A two-row version of the same engine was also produced, known as the Gnome 14 Omega-Omega or Gnome 100 hp. The prototype Omega engine still exists, and is on display at the United States' National Air and Space Museum.

Like all early Gnome et Rhône engines the Omega features a single pushrod driven exhaust valve on the cylinder head; the intake valve is located in the piston crown, opening by inertia on the downstroke and feeding the intake charge from the crankcase into the upper part of the cylinder. No throttle is provided, the pilot controls the aircraft's speed by switching off the ignition when necessary.