COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Embraer EMB-120 (Brasilia) Series Aeroplanes AD/EMB-120/20 Flight Data Recorder Coupler Screws 12/97 Applicability: EMBRAER EMB 120 aircraft S/N. 120003, 120004, 120006 to 120308 inclusive, 120310, 120312, 120314, 120316 to 120322 inclusive and 120325. Requirement: Verify alignment between the flight data recorder potentiometers and the flight control mechanism shafts and lock the flexible coupler screws by applying Loctite adhesive to its threads in accordance with EMBRAER Service Bulletin Nr. 120-31- 0038. Note: Brazilian AD 97-08-01-EMBRAER Amdt 39-793 refers. Compliance: Unless previously accomplished within the next 400 hours time in service. This airworthiness directive becomes effective on 6 November 1997. Background: The Brazilian DCA has found the occurrence of erroneous flight control displacement records in the flight data recorder caused by looseness of the flexible coupler screws.