The first prototype, designated as XZ-37, first flew on 29 March 1963 (other sources:29 June). It was a cantilever low-wing monoplane of tubular metal construction, the wings and stabilizers covered with duralumin and the fuselage and control surfaces made of fabric. It had a fixed undercarriage with a fully castering tailwheel, but locked to the rudders for ground handling.
The inaugural model, labeled as XZ-37, took to the skies on 29 March 1963 (or alternatively, 29 June). It was a cantilever low-wing monoplane constructed from tubular metal, with duralumin covering the wings and stabilizers, and fabric used for the fuselage and control surfaces. The aircraft featured a fixed undercarriage with a fully rotating tailwheel, but it was secured to the rudders during ground handling.