COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes
AD/DHC-8/55 Horizontal Stabiliser Skin Disbonding Follow-up 12/98
Applicability: All DHC-8, Series 100 and 300 aircraft which have horizontal stabilisers, serial numbers CAP 003 through CAP 214 fitted.
Requirement: 1. For Horizontal Stabilisers, Serial Numbers CAP 003 through CAP 050:
Perform an Ultrasonic Bond Inspection of the upper and lower skin panels (part number 85510025 and 85510026) for disbonding as outlined in de Havilland Non Destructive Testing Manual, PSM 1-8-7A, Part 5, Section 55-00-01.
2. For Horizontal Stabilisers, Serial Numbers CAP 003 through CAP 214:
The inspection interval in the Airworthiness Limitations List (AWL) is reduced from 3 years to 2 years in accordance with Temporary Revision (TR) No. AWL 63 of the AWL in the Maintenance Program Manual PSM 1-8-7 (for Series 100 aircraft) and TR No. AWL 3-70 of the AWL in the Maintenance Program Manual PSM 1-83-7 (for Series 300 aircraft). These inspections are to be phased in as specified in Compliance paragraph 2.
Disbonds beyond the local disbond limits defined in de Havilland document PSM 1- 8-7A, Part 5, Section 55-00-01 shall be repaired before further flight.
Note: Transport Canada AD CF-98-24 refers.
Compliance: 1 Unless already accomplished within the last 3 months, before 5 December 1998; repeat between 12 and 14 months after the initial inspection.
2. a. For Horizontal Stabilisers Serial Number CAP 003 through CAP 050:
Following the Compliance 1 repeat inspection, inspect within the next 2 years and thereafter at intervals not to exceed 2 years.
2. b. For Horizontal Stabilisers Serial Numbers CAP 051 through CAP 214:
- Where the next inspection falls due in 1998, unless already accomplished, perform the inspection as scheduled and repeat thereafter at intervals not to exceed 2 years.
ii. Where the next inspection falls due in 1999, unless already accomplished, perform the inspection no later than 31 December 1998 and repeat thereafter at intervals not to exceed 2 years.
iii. Where the next inspection falls due after 1 January 2001, perform the inspection 1 year earlier and repeat thereafter at intervals not to exceed 2 years.
This Airworthiness Directive becomes effective on 5 November 1998.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Background: As a result of the inspection required by AD/DHC-8/51, a total of four aircraft with serial numbers close together were determined to have disbonds of the doublers and stringers on the upper and lower skin panels of the horizontal stabiliser. This discovery indicates that the bonding process was defective on a single batch of skins. The follow-up inspections of this Directive will ensure that no further problems exist in the above single batch or other batches of the bonded skin panels.
Overview
The Civil Aviation Regulations 1998, as amended by the Civil Aviation Safety Authority, establish a regulatory framework for ensuring the safety of aviation operations within Australia. The regulations include specific directives for maintaining the airworthiness of aircraft, with Part 39 addressing airworthiness directives. One such directive, AD/DHC-8/55, targets Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes, specifically focusing on the issue of horizontal stabiliser skin disbonding. This directive was introduced to address a problem identified in a batch of aircraft where the bonding process for the horizontal stabiliser skin panels was defective, leading to disbonding issues. The policy objective is to ensure that these aircraft maintain their airworthiness through regular and thorough inspections, thereby enhancing safety standards and preventing potential mid-flight failures. The directive mandates specific inspection procedures and intervals to be followed by aircraft operators to ensure ongoing compliance with safety standards.
Scope and Application
The Civil Aviation Safety Authority’s Airworthiness Directive AD/DHC-8/55 applies to all Bombardier (Boeing Canada/De Havilland) DHC-8 Series 100 and 300 aircraft that have horizontal stabilisers, specifically those with serial numbers ranging from CAP 003 through CAP 214. This legislation mandates that an ultrasonic bond inspection of the upper and lower skin panels of the horizontal stabilisers must be conducted to check for disbonding, in accordance with the de Havilland Non Destructive Testing Manual. The inspections are required for specific serial numbers, with additional requirements for inspection intervals based on the serial numbers. The directive outlines a phased approach for inspections, with a reduction in the inspection interval from 3 years to 2 years. Any disbonds beyond the specified local disbond limits must be repaired before further flight. This directive becomes effective from 5 November 1998 and is part of the broader regulatory framework set out in the Civil Aviation Regulations 1998.
Key Provisions
The Civil Aviation Regulations 1998, particularly in Part 39 - 105, under the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, includes specific provisions for Bombardier (Boeing Canada/De Havilland) DHC-8 Series aeroplanes (sections 1-3). This directive, AD/DHC-8/55, addresses the issue of horizontal stabiliser skin disbonding, focusing on aircraft with serial numbers CAP 003 through CAP 214. The directive mandates an ultrasonic bond inspection of the upper and lower skin panels for disbonding, as outlined in the de Havilland Non Destructive Testing Manual, PSM 1-8-7A, Part 5, Section 55-00-01 (section 1). Additionally, it reduces the inspection interval from 3 years to 2 years, depending on the serial number range of the aircraft (section 2). Repairs are necessary for any disbonds that exceed the local disbond limits specified in the de Havilland document (section 1).
The obligations imposed by this directive include conducting the specified ultrasonic bond inspections at the required intervals, ensuring that any identified disbonds are repaired before further flights, and updating the Airworthiness Limitations List (AWL) to reflect the new inspection intervals (section 1). Operators of DHC-8 Series 100 and 300 aircraft within the specified serial number range must comply with these inspection and repair requirements to maintain airworthiness (section 2). The directive also provides a phased implementation schedule, depending on the serial number of the aircraft and the timing of the next inspection (section 2).
Breaches of the requirements set out in this directive can result in serious safety implications, and the consequences are severe. While specific penalties are not detailed within the directive itself, any non-compliance with airworthiness directives under the Civil Aviation Regulations 1998 can lead to enforcement actions by the Civil Aviation Safety Authority (CASA). These actions can include fines, enforcement notices, and potential suspension or revocation of the aircraft's certificate of airworthiness. Such severe consequences underscore the importance of adhering to the inspection and repair requirements outlined in the directive.