AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section. Embraer EMB-120 (Brasilia) Series Aeroplanes AD/EMB-120/46 Fuel System 8/2007 DM Applicability: All EMB-120( ) Brasilia aeroplanes. Requirement: 1. Revise the operator's approved system of maintenance to include the tasks 15 to 18 of Section 6 - "Part E: Fuel System Limitations", as shown in the Temporary Revision 22-1 of the Maintenance Review Board Report (MRBR) for the Embraer EMB-120( ) aircraft, dated 18 November 2005 or later revision approved by the Brazilian Agência Nacional de Avição Civil (ANAC), with the intervals stated in that document. 2. Carry out the functional checks (FNC) and detailed visual inspections (DET) required by tasks 15 to 18 of Section 6 - "Part E: Fuel System Limitations", as shown in the Temporary Revision 22-1 of the MRBR for the Embraer EMB-120( ) aircraft, or later revision approved by the ANAC. 3. Revise the operator's approved system of maintenance to include the items 1) and 2) of Section 6 - "Part D: Critical Design Configuration Control Limitations", as shown in Revision 22 of the MRBR for the Embraer EMB-120( ) aircraft, dated 22 March 2005, or later revision approved by the ANAC, with the restrictions imposed by that document. Note 1: The revision or variation of an operator's system of maintenance must be approved by the CASA under Civil Aviation Regulation 42R. Note 2: ANAC AD 2007-05-02 Amdt 39-1183 refers. Compliance: For Requirement 1 - Within the next 30 calendar days after the effective date of this Directive. For Requirement 2 - Within the next 4000 hours time in service or 48 calendar months after the effective date of this Directive, whichever occurs first and thereafter repeat these tasks at the intervals stated in the MRBR. For Requirement 3 - Within the next 30 calendar days after the effective date of this Directive. This Airworthiness Directive becomes effective on 29 June 2007. Background: The ANAC has advised that it has been found that former revisions of the EMB-120( ) MRBR do not fully comply with some Critical Design Configuration Control Limitations (CDCCL) and Fuel System Limitations (FSL). These limitations are necessary to preclude ignition sources in the fuel system, as required by Regulamento Brazileiro de Homologação Aeronáutica (RBHA) E88/United States Special Federal Aviation Regulation (SFAR) 88. Since this condition affects flight safety and corrective action is required, this Directive requires the revision of operator's approved system of maintenance and the completion of certain inspections and/or functional checks. David Punshon Delegate of the Civil Aviation Safety Authority 14 June 2007