COMMONWEALTH OF AUSTRALIA (Civil Aviation Safety Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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.

Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AD/DHC-8/92 RDS86 Weather Radar Circuit Breakers 7/2003

Applicability: DHC-8 Model 102 aircraft, serial numbers 023 through 392, equipped with RDS86 Weather Radar System but excluding those aircraft equipped with option CR834CH00284.

Requirement: For aircraft with options CSI 82309, CR834CH82309 or CR811CH82309 incorporated - Modify the electrical power circuit in accordance with the procedures detailed in paragraph 2.2 of Bombardier ModSum IS8Q3450000 by replacing the 7.5 amp circuit breaker with a 5 amp breaker and installing an additional 3 amp breaker.

For aircraft without options CSI 82309, CR834CH82309 or CR811CH82309 incorporated - Modify the electrical power circuit in accordance with the procedures detailed in paragraph 2.3 of ModSum IS8Q3450000 by replacing the 7.5 amp circuit breaker with a 5 amp breaker and installing an additional 3 amp breaker.

Note: Transport Canada AD CF-2003-13 refers.

Compliance: Within twelve months after the effective date of this Directive.

This Airworthiness Directive becomes effective on 10 July 2003.

Background: Overheating of the radar ribbon cable and/or the radar indicator can result in smoke in the cockpit. The overheating can occur because the 7.5 amp circuit breaker installed for both the radar transmitter and radar indicator does not provide adequate protection in the event of a short circuit within the radar indicator.

Jim Coyne

Delegate of the Civil Aviation Safety Authority 30 May 2003

The above AD is notified in the Commonwealth of Australia Gazette on 18 June 2003.

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