56-09-02 MARTIN: Applies to All Models 202, 202A, and 404 Aircraft.
Compliance required by September 1, 1956.
In order to eliminate shearing of rivets securing the rudder torque tube flange, P/N 2021U42196, to the rudder torque tube, P/N 2021D19331, caused by gust buffeting with gust locks not engaged and resulting in loss of adequate and/or positive rudder control, it is necessary to replace the 3/16-inch rivets with 1/4-inch 24ST heat treated rivets.
(Martin Service Instruction Letters No. 202/202A-36 and No. 404-69 cover this same subject.)