Summary
This document proposes to adopt a new airworthiness directive (AD) that would apply to all LET Aeronautical Works (LET) Model L-13 ``Blanik'' sailplanes. The proposed AD would require painting (using a contrasting color, i.e., red paint) the left hand elevator drive mechanism in order to not have the elevator drive bellcrank inadvertently installed backwards. The proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the Czech Republic. The actions specified by the proposed AD are intended to prevent the elevator drive bellcrank from being installed backwards, which could result in an incorrect rigging of the elevator flight control with potential reduced or loss of control of the sailplane.