AD/AC/56 Amdt 3 - Elevator Control System Bob Weight Installation - Inspection and Modification

Overview

The Civil Aviation Regulations 1998, enacted by the Australian Parliament, encompass a comprehensive regulatory framework for ensuring the safety and efficiency of civil aviation within Australia. One particular legislative instrument, F2006B02115, pertains to Airworthiness Directives (ADs) which are issued under the authority of the Civil Aviation Safety Authority (CASA) to address specific safety issues. This particular AD, issued for the Twin Commander (Gulfstream/Rockwell/Aerocommander 500, 600, and 700) series aeroplanes, targets the elevator control system bob weight installation. The directive was introduced to address the identified problem of cracks in the bob weight side supports, which had been discovered in several overseas-registered aircraft. The policy objective behind this AD is to mandate inspections and modifications to ensure the continued airworthiness and safety of these aircraft, thereby mitigating potential risks associated with structural integrity issues.

Scope and Application

The Civil Aviation Regulations 1998, particularly Part 39 - 105, under the authority of the Civil Aviation Safety Authority, mandate specific airworthiness directives applicable to the Twin Commander (Gulfstream/Rockwell/ Aerocommander 500, 600 and 720) series aeroplanes. This directive focuses on the elevator control system bob weight installation, requiring an inspection and subsequent modification to ensure safety. It applies to specific models and serial numbers of the aforementioned aircraft series, excluding those that have already complied with particular Rockwell International Service Bulletins. The directive mandates an initial inspection within 25 hours of service after 8 February 1982, followed by inspections at intervals not exceeding 60 hours of service until the modification is made. The modification must be completed within 500 hours of service after the same date. Aircraft certified under AD/AC/56B and AD/AC/58B are deemed to comply with this directive, consolidating earlier requirements. The directive extends nationally and applies to all Commonwealth, state, and territory jurisdictions within Australia, ensuring uniform safety standards across the country.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39, Section 105, under the Civil Aviation Safety Authority (CASA) schedule of airworthiness directives, contains detailed requirements for the inspection and modification of elevator control systems in Twin Commander (Gulfstream/Rockwell/Aerocommander 500, 600, and 700) series aeroplanes. This directive, AD/AC/56 Amendment 3, pertains to the installation of a bob weight in the elevator control system and is applicable to specific models and serial numbers of the aforementioned aircraft, excluding those that have already complied with certain Rockwell International Service Bulletins (129 Rev. 4 and 136 Rev. 3 dated 26 January 1981). The directive references Gulfstream American Service Information No. SI-176 and acknowledges Rockwell International Service Bulletin No. 179 and FAA AD 75-12-09 Amendment 39-4246. The obligations imposed by this directive require operators of the affected aircraft to conduct an initial inspection of the elevator control system within 25 hours of time in service after 8 February 1982. This inspection must be carried out before the aircraft accumulates 500 hours of time in service after the same date, with subsequent inspections occurring at intervals not exceeding 60 hours of time in service until the modification is completed. Additionally, the directive mandates that the modification itself must be completed within 500 hours of time in service following 8 February 1982. It is noted that aircraft certified to comply with AD/AC/56B and AD/AC/58B are deemed to comply with this directive. Failure to comply with the requirements of this airworthiness directive may result in various consequences. While the specific offences, penalties, or civil/criminal consequences are not explicitly detailed in the text provided, non-compliance with CASA directives generally can lead to significant regulatory action. This may include enforcement actions such as fines, suspension or revocation of aircraft certificates of airworthiness, and potential criminal charges against responsible parties, depending on the severity and circumstances of the breach. The maximum penalties would be determined by the applicable civil aviation legislation and the specific circumstances of each case.