As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AILERON FAILED TO RETURN TO NEUTRAL POSITION DURING ROLL CENTERING SPRING FUNCTIONAL TEST IN ACCORDANCE WITH AMM CH 27-10. INVESTIGATION REVEALED THE FACTORY-INSTALLED CENTERING SPRING IS INCORRECT (TOO SHORT) PER THE IPC CH 27-10-02. THE AILERON CENTERING SPRING WAS REPLACED AND TESTED OK. NOTE: THIS SAME DEFECT HAS BEEN IDENTIFIED ON NON-FAA REGISTERED AIRCRAFT OF THE SAME TYPE, AND APPEARS TO BE A PRODUCTION ERROR.