Extract from EASA AD 2014-0067, effective 1 April:
Control cable pulleys made from plastic (white or brown material) in the rudder control unit were reported to develop cracks due to aging. In one case, jamming of the rudder control unit was reported.
This condition, if not detected and corrected, could cause cable pulleys to break, potentially jamming the rudder control unit and resulting in loss of control of the sailplane.
To address this potential unsafe condition, Fiberglas-Technik issued Technische Mitteilung/Service Bulletin TM-G05/SB-G05 and Anweisung/ Instructions A/I-G05 (one document) to provide instructions for the replacement of plastic cable pulleys with pulleys made from aluminium.