Thinking of building your own aircraft? Almost finished your project but still haven't selected your prop? Whether you're in the initial stages of a future kit or 98% complete, Hartzell has the prop you need to get the greatest efficiency out of your kitplane. . At Hartzell, we have a range of FAA-certified props availble for the experimental market, in addition to some non-certified models used mainly for air racers and one-off applications.