AD/B737/91 - Main Deck Cargo Door Hinge, Shim and Fairing

Overview

The Civil Aviation Regulations 1998, as amended, were enacted by the Australian Government to ensure the safety of civil aviation within Australia and its territories. Specifically, Part 39 - 105 within this legislation addresses airworthiness directives that must be complied with to maintain the safety standards of aircraft. One such directive, AD/B737/91, pertains to Boeing 737 Series aeroplanes and mandates the replacement of certain components of the main deck cargo door to prevent structural failure, which could lead to the loss of the cargo door and rapid decompression. This directive was introduced to address the specific issue identified with the main deck cargo door hinge shims and fairings, ensuring that these components are replaced to maintain the aircraft's airworthiness and passenger safety. The policy objective is to mitigate risks associated with structural integrity, thereby enhancing overall aviation safety.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates that the Airworthiness Directive AD/B737/91 applies to Boeing 737-300 Series aeroplanes equipped with a main deck cargo door installed in accordance with Supplemental Type Certificate (STC) SA2969SO and detailed in Pemco Aeroplex Inc. Service Bulletin 737-52-0012, Revision 2. This regulation is issued under the authority of the Civil Aviation Safety Authority and is applicable on a national scale across Australia, ensuring compliance with civil aviation safety standards. The directive requires the replacement of the forward and aft hinge shims and the lower hinge fairings of the main deck cargo door with new components as specified in the referenced service bulletin, to prevent potential loss of structural integrity which could lead to the loss of the cargo door and subsequent rapid decompression. Compliance with this directive must be achieved before the aircraft reaches 12,000 landings from the date of installation of the STC SA2969S0 modification, or before 15 December 1995, whichever is the later date. The directive references FAA AD 94-12-12 for further context and applicability.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, include a Schedule of Airworthiness Directives (ADs) that mandate certain safety measures for specific aircraft models. One such AD is AD/B737/91, which pertains to Boeing 737 Series Aeroplanes, particularly the main deck cargo door hinge, shim, and fairing (section 1). This AD applies to the B737-300 series aircraft that have had their main deck cargo door installed according to a particular Supplemental Type Certificate (STC) SA2969SO, and are listed in a specific service bulletin (section 2). The directive mandates that the forward and aft hinge shims, as well as the lower hinge fairings of the main deck cargo door, must be replaced with new components that comply with Pemco Aeroplex Inc. Service Bulletin 737-52-0012, Revision 2 (section 3). Operators of the affected aircraft must adhere to the requirements set out in AD/B737/91 to maintain the airworthiness of their aircraft. Specifically, they must replace the specified parts of the main deck cargo door with the new components as directed. This ensures the structural integrity of the cargo door, thereby preventing potential issues such as the loss of the door and subsequent rapid decompression, which could have catastrophic consequences (section 4). Compliance with this directive is crucial for safety and must be achieved within a certain timeframe or by a specific date. The compliance period is set at 12,000 landings from the date of the STC SA2969SO modification or by 15 December 1995, whichever is later (section 5). Failure to comply with the provisions of AD/B737/91 can result in serious consequences. The legislation does not explicitly state the penalties or consequences for non-compliance within the text provided, but typically, non-compliance with airworthiness directives can lead to severe civil or criminal penalties. These may include fines, suspension or revocation of the aircraft's certificate of airworthiness, and potential criminal charges if the non-compliance leads to an accident or endangers flight safety. The Civil Aviation Safety Authority (CASA) enforces these regulations and has the authority to take appropriate action against entities that fail to adhere to the mandated safety directives (section 6).