The Coax-P is a contra-rotating propeller developed by NeuraJet of Senftenbach, Austria and Sun Flightcraft of Innsbruck, Austria for the Rotax 503 and Rotax 582 aircraft engines for use on ultralight aircraft.
[1][2] The Coax-P was designed by Hans Neudorfer of NeuraJet and Herbert Hofbauer of Sun Flightcraft.
[1][2][3] The propeller system was designed for ultralight trikes and powered parachutes.
[1][2] The design has two propellers, each with two composite, ground adjustable blades and uses a 3.7:1 gear box type reduction drive.
Should the propeller be out of place by only two millimeters the effectiveness declines and the noise level increases dramatically.