The Omega rotary engine

This rotary aircraft engine, which was presented at the first aeronautics exhibition in 1908, has seven radial cylinders. The crankshaft is fixed and a seven-arm connecting rod can freely turn on its crankpin. Each arm has a piston that slides in and out of one of the cylinders. The cylinder block rotates around the crankshaft, driving the connecting rod and pistons. Its off-centre position in relation to the connecting rod allows the pistons to complete their strokes between two extreme positions, the high and low dead spots. This complex solution attests to the Gnome Company's outstanding engineering; the cylinder block's weight required a meticulous balance between the moving parts. The Omega powered the plane that Roland Garros flew across the Mediterranean in 1913. Despite its limited power, a gyroscopic effect hindering navigation and the splattering of viscous castor oil on the pilot, the Omega, nicknamed "Rototo", was the most successful engine of the First World War.