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 39.1 (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. Beechcraft 1900 Series Aeroplanes AD/BEECH 1900/42 Ventilation Blower Assemblies 3/2004 Applicability: Beech 1900 model aeroplanes, as listed below. Model 1900 1900C 1900 (C-12J) 1900D Serial Number UA-3 UB-1 through UB-74 and UC-1 through UC-174 UD-1 through UD-6 UE-1 through UE-427 Requirement: 1. Unless previously accomplished, check the maintenance records, in accordance with Raytheon Mandatory Service Bulletin SB 21-3448 issued October 2002, to determine if a part number (P/N) 114-380028-1, 114-380028-3, 114-380028-5 or 114-380028-7 ventilation blower assembly is installed. If, by checking the maintenance records, it can be definitely demonstrated that a P/N 114-380028-1, 114-380028-3, 114-380028-5 or 114-380028-7 ventilation blower assembly is not installed, no further action is required. 2. If, by checking the maintenance records, it is determined that a P/N 114-380028- 1, 114-380028-3, 114-380028-5 or 114-380028-7 ventilation blower assembly is installed, carry out the following in accordance with SB 21-3448. 1. For P/N 114-380028-1 - Modify in accordance with Raytheon Service Bulletin (SB) No 2721, issued January 1997, prior to incorporating Electromechanic Technologies Modification Kit No 630-203-01 and changing the P/N to 114-380028-11. Note 1: Blower assembly P/N 114-380028-1 may have already been modified in accordance with SB No 2721 as a result of AD/BEECH 1900/21 (FAA AD 97-22-16). b. For P/N 114-380028-3 - Incorporate Advanced Industries Modification Kit No BC80A-901-3 and change the P/N to 114-380028-9. c. For P/N 114-380028-5 with a serial number (S/N) of 2162 or above or with a S/N of 2162 with an 'A' suffix - No modification is required, change the P/N to 114-380028-11. d. For P/N 114-380028-5 with a S/N prior to 2162 without an 'A' suffix - Incorporate Electromechanic Technologies Modification Kit No 630-203-01 and change the P/N to 114-380028-11. e. For P/N 114-380028-7 - Incorporate Advanced Industries Modification Kit No BC80A-901-3 and change the P/N to 114-380028-9. 3. If, it cannot be definitely shown that a P/ N 114-380028-1, 114-380028-3, 114- 380028-5 or 114-380028-7 ventilation blower assembly is installed through the maintenance records check, carry out an inspection in accordance with SB 21- 3448 to determine the P/N of the installed ventilation blower assembly. 4. If, as a result of the Requirement 3 inspection, a ventilation blower assembly with P/ N 114-380028-1, 114-380028-3, 114-380028-5 or 114-380028-7 is found to be installed carry out Requirement 2. 5. Ventilation blower assembly P/N 114-380028-1, 114-380028-3, 114-380028-5 or 114-380028-7 may not be installed on any aeroplane as a replacement part unless it has been modified in accordance with Requirement 2 and re-identified with a new P/N. Note 2: FAA AD 2004-01-13 Amdt 39-13427 refers. Compliance: For Requirement 1 - Within 800 hours time in service (TIS) after the effective date of this Directive. For Requirement 2 - Before further flight. For Requirement 3 - Within 800 hours TIS after the effective date of this Directive. For Requirement 4 - Before further flight. For Requirement 5 - As of the effective date of this Directive. This Airworthiness Directive becomes effective on 18 March 2004. Background: This Directive supersedes AD/BEECH 1900/21, which has been cancelled. AD/BEECH 1900/21 required the replacement of the bearings on the vent blower assemblies with improved design bearings and installation of a thermal protection device for the vent blowers. That Directive resulted from reports of vent blower assembly bearings seizing and locking the blower motor. This Directive requires the incorporation of further product improvement modifications on all affected vent blower assemblies. This Directive is the result of reports that vent blower assemblies modified in accordance with AD/BEECH 1900/21 are still malfunctioning. James Coyne Delegate of the Civil Aviation Safety Authority 4 February 2004 The above AD is notified in the Commonwealth of Australia Gazette on 25 February 2004.