COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
SAAB SF340 Series Aeroplanes
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 CAR 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.
AD/SF340/78 Landing Gear Electrical Circuit Breaker 5/2000
Applicability: Model SF340A aeroplanes, serial numbers (S/N) 004 through 159 inclusive and Model 340B aeroplanes, S/N 160 through 459 inclusive, except 342, 379, 395, 409,
431 and 455.
Requirement: Install a new electrical circuit breaker and related wiring in accordance with SAAB Aircraft AB Mandatory Service Bulletin SAAB 340-32-120 dated 25 February 2000.
Note: LFV AD 1-155 refers.
Compliance: Within six months from the effective date of this Directive.
This Airworthiness Directive becomes effective on 18 May 2000.
Background: The Swedish Civil Aviation Administration advised that a number of occurrences have been reported of emergency extension of the landing gears being necessary due to a popped circuit breaker which it was not possible to reset. This circuit breaker is also common to the ‘Weight on Wheels’ and ‘Landing Gear Locked Down’ signals to other systems such ‘Nose Wheel Steering’ and ‘Flight Idle Stop’. Not being able to reset the circuit breaker therefore causes failure of the Nose Wheel Steering system which results in reduced capability to steer the aircraft on the ground.
This Directive requires the addition of a new circuit breaker to supply 28VDC to relays that supply the ‘Weight on Wheels’ and ‘Landing Gear Locked Down’ signals to other systems.
Eugene Paul Holzapfel
Delegate of the Civil Aviation Safety Authority 5 April 2000
The above AD is notified in the Commonwealth of Australia Gazette on 19 April 2000.
Overview
The Civil Aviation Regulations 1998 (CAR 1998) were enacted to establish safety standards for civil aviation in Australia, addressing the need for comprehensive regulation of aircraft operations and maintenance to ensure public safety. The CAR 1998 were introduced by the Australian Parliament to provide a legislative framework for the Civil Aviation Safety Authority (CASA) to oversee and enforce compliance with aviation safety standards. One such regulation is the Airworthiness Directive issued by CASA, as seen in AD/SF340/78, which was introduced to address a specific safety issue identified with the Saab SF340 series aeroplanes. This Airworthiness Directive mandates corrective actions to be taken on certain models of SF340 aeroplanes to rectify an unsafe condition related to the landing gear electrical circuit breaker. The directive aims to prevent potential failures that could compromise the aircraft’s landing gear system and associated systems, thereby ensuring continued airworthiness and safety of the affected aircraft.
Scope and Application
This Airworthiness Directive (AD) issued under subregulation 39.1 (1) of the Civil Aviation Regulations 1998 applies to Saab SF340 Series aeroplanes, specifically those of Model SF340A with serial numbers 004 through 159 inclusive and Model 340B with serial numbers 160 through 459 inclusive, with the exception of aeroplanes with serial numbers 342, 379, 395, 409, 431, and 455. This AD mandates that a new electrical circuit breaker and related wiring be installed in accordance with the instructions set out in SAAB Aircraft AB Mandatory Service Bulletin SAAB 340-32-120 dated 25 February 2000. The directive comes into effect on 18 May 2000, and the compliance period for implementing the required actions is within six months from this date. The AD is applicable across the Commonwealth of Australia, as it is issued by the Civil Aviation Safety Authority, and it aims to address safety issues related to the landing gear electrical circuit breaker which, if not reset, can lead to the failure of critical systems such as the Nose Wheel Steering system. This directive is published in the Commonwealth of Australia Gazette on 19 April 2000, ensuring that all relevant stakeholders are informed of the safety measures required.
Key Provisions
The key provisions of this Airworthiness Directive (AD) are outlined in sections which define the applicability, requirement, and compliance of the directive. Section (a) of the applicability indicates that this directive applies to SAAB SF340A aeroplanes with serial numbers (S/N) 004 through 159 inclusive and SAAB SF340B aeroplanes with S/N 160 through 459 inclusive, excluding specific serial numbers 342, 379, 395, 409, 431 and 455. Section (b) of the requirement mandates the installation of a new electrical circuit breaker and associated wiring in accordance with the SAAB Aircraft AB Mandatory Service Bulletin SAAB 340-32-120 dated 25 February 2000. Section (c) of the compliance states that this action must be taken within six months from the effective date of the directive, which is 18 May 2000.
This AD imposes obligations on aircraft operators and maintenance personnel to ensure the safety of the SAAB SF340 aeroplanes by installing the new electrical circuit breaker and wiring as specified. The directive is grounded in safety concerns raised by the Swedish Civil Aviation Administration, which reported multiple instances of emergency extension of the landing gear due to a popped circuit breaker that could not be reset. This issue also affects the 'Weight on Wheels' and 'Landing Gear Locked Down' signals, leading to potential failures in the Nose Wheel Steering system and a reduction in the aircraft's ground steering capabilities.
Failure to comply with this Airworthiness Directive may result in serious safety risks and could potentially lead to accidents or incidents involving the affected aircraft. While the specific civil or criminal consequences are not detailed in the directive, non-compliance with ADs generally can lead to enforcement actions by the Civil Aviation Safety Authority, including fines, suspension of airworthiness certificates, or other regulatory penalties. The directive does not specify maximum penalties, but such penalties would typically be determined under the broader framework of the Civil Aviation Regulations 1998.