EASA 2019-0129

Requires replacement of horizontal stabilizer rear attachment bolts having P/N 555.10.12.139 and production order number FAUF 10169753, 10171067 or 10171267. According to EASA, horizontal stabilizer rear attachment bolts were detected on the final assembly line that had not received correct heat treatment. Subsequent investigation determined that certain parts were improperly manufactured and consequently have reduced material properties. AD also prohibits affected parts from being installed.