AD/DHC-8/58 - Ladder Plate at Wing Station 139

Overview

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, establish the Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives, including AD/DHC-8/58. This directive was enacted in 1998 to address a critical safety concern involving Bombardier (Boeing Canada/De Havilland) DHC-8 Series aeroplanes. The problem it sought to address was the detection and prevention of fatigue cracks in the ladder plates at Wing Station 139, which could compromise the structural integrity of the aircraft wing. The objective of this directive, as outlined in the regulation, is to ensure that all applicable DHC-8 aircraft models undergo regular inspections to identify and rectify any such cracks before they reach a critical size. The directive mandates that inspections be conducted in accordance with the Maintenance Program Manual (MPM) Temporary Revisions specified for each model, with the requirement to report any discovered cracks to Bombardier Regional Aircraft Division for further action. This proactive approach ensures that potential safety hazards are identified and addressed, thereby maintaining the airworthiness of the aircraft. The directive becomes effective on 3 December 1998, with compliance required at the initial and repetitive flight cycles as specified in the MPM Temporary Revisions.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39-105, which pertains to Airworthiness Directives for Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes, applies to all DHC-8 aircraft models including 101, 102, 103, 106, 201, 202, 301, 311, 314, and 315. This directive mandates regular inspections of the ladder plates at wing station 139 to detect potential cracks before they compromise the structural integrity of the wing. Compliance with the directive involves following the specific Maintenance Program Manual (MPM) temporary revisions outlined for each model, with inspections to be conducted at the initial and repetitive flight cycles as specified in these revisions. If cracks are detected, operators must report to Bombardier Regional Aircraft Division, Downsview, Ontario for further instructions. The directive is effective from 3 December 1998 and references Transport Canada AD CF-98-30, highlighting its jurisdictional and collaborative nature in ensuring aviation safety.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, under the Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives, mandates inspection and maintenance procedures for certain Bombardier (Boeing Canada/De Havilland) DHC-8 series aeroplanes (section 1). This directive applies to all DHC-8 aircraft models, including 101, 102, 103, 106, 201, 202, 301, 311, 314, and 315 (section 2). The primary requirement is to inspect the ladder plate at wing station 139 to detect any cracks before they reach a critical size, which could compromise the wing's strength (section 2). The inspection must be carried out in accordance with the Maintenance Program Manual (MPM) Temporary Revisions detailed in the directive (section 2). For instance, models 101, 102, 103, and 106 should follow PSM 1-8-7AWL-59, while models 201 and 202 should adhere to PSM 1-82-7AWL2-11. Models 301, 311, 314, and 315 should comply with PSM 1-83-7AWL3-64 (section 2). If any cracks are discovered, the aircraft must not be flown until the matter is resolved by Bombardier Regional Aircraft Division in Downsview, Ontario (section 2). Compliance with these inspections is mandatory at the initial and repetitive flight cycles as specified in the MPM Temporary Revisions (section 4). Entities governed by this directive, primarily aircraft operators and maintenance personnel, must ensure that the inspections are conducted meticulously and in adherence to the specified timelines and procedures (section 2). They must also report any detected cracks to Bombardier Regional Aircraft Division promptly (section 2). Failure to comply with these requirements could result in significant safety risks, as undetected critical cracks could lead to structural failures during flight. The regulations do not explicitly state penalties for non-compliance; however, any resultant accidents or safety breaches may lead to severe consequences, including civil and criminal liabilities under broader aviation safety laws. The severity of penalties could include substantial fines or imprisonment, depending on the outcome and the extent of the non-compliance. Therefore, adherence to these directives is critical to maintaining airworthiness and ensuring passenger safety.