Airworthiness Directives; PZL-Bielsko Model SZD-50-3 “Puchacz” Gliders

We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as a discrepancy between the design documentation and the Technical Service Manual. In 1981, a castellated nut with cotter pin was introduced to secure the rudder, replacing the self-locking nut through PZL-Bielsko Bulletin No. BE-06/50-3/81. This change has not been introduced to the Technical Service Manual and use of a self-locking nut, in accordance with the Manual, is still possible. We are issuing this AD to require actions that are intended to address the unsafe condition described in the MCAI.