COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Beechcraft 1900 Series Aeroplanes AD/BEECH 1900/23 Radio Switching Panel 7/98 Applicability: Model 1900D aeroplanes with serial numbers UE-1 through UE-160 inclusive. Requirement: 1. Inspect the radio switching panel, the electrical connectors and the relay printed circuit board (PCB) for moisture or corrosion in accordance with the Accomplishment Instructions of Raytheon Service Bulletin (SB) 2643 dated August 1996. 2. If moisture and/or corrosion is found during the Requirement 1 inspection, carry out the following actions: 1. moisture is found - clean and dry the component in accordance with SB 2643, then locate and eliminate the source of the moisture. b. corrosion is found - either clean or replace the component in accordance with SB 2643, then locate and eliminate the cause of the corrosion. 3. Inspect the nose avionics wire harnesses for proper installation in accordance with SB 2643. 4. If any harness is found to be incorrectly installed during the Requirement 3 inspection, secure it with cable ties in accordance with SB 2643. 5. Remove the A017 component PCB part number (P/N) 101-342536-1 and replace it with a new A017 component PCB P/N 101-342536-5, in accordance with SB 2643. Note: FAA AD 98-09-12 Amdt 39-10493 refers. Compliance: 1. Within the next 1000 hours time in service after the effective date of this directive, but no later than 12 November 1998. 2. Prior to further flight, immediately after the Requirement 1 inspection. 3. Within the next 1000 hours time in service after the effective date of this directive, but no later than 12 November 1998. 4. Prior to further flight, immediately after the Requirement 3 inspection. 5. Within the next 1000 hours time in service after the effective date of this directive, but no later than 12 November 1998. This airworthiness directive becomes effective on 18 June 1998. Background: The FAA has received several reports of loss of the pilot/copilot intercom system, VHF communication system and passenger address system. This directive specifies actions which are designed to decrease the likelihood of failure of these systems, which could result in loss of all communication during critical phases of flight. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES