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-8/28
Amdt 1
Underwing Fairing Angles 12/95
Applicability: DHC-8 aircraft, Models 311 and 315, serial numbers 240 through 279.
Requirement: Inspect the rear face of the left hand and right hand underwing fairing angles for cracks, in accordance with Part A of the Accomplishment Instructions in de Havilland Service Bulletin A8-53-46 Rev A.
Note: Transport Canada AD CF-93-10R1 refers.
Compliance: Inspect before 6930 flights or within 100 flights from 7 June 1993, which ever occurs later. Re-inspect at intervals not to exceed 6930 flights until replaced with new angles.
The Compliance of the initial issue of this Directive remains unchanged. This Amendment is effective from 9 November 1995.
Note: If an angle is replaced, the inspection requirement for the new angle reverts to that specified for the standard aircraft, which has a threshold of 40000 flights and a repeat interval of 8194 flights (Maintenance Task 5310/15K refers).
Background: A number of titanium fairing angles made for the model 301 were reworked to fit model 311 aircraft during manufacture. The rework entailed weld-filling three fastener holes and re-drilling the holes to suit the model 311 aircraft. The welds were made of commercially pure titanium, with a hardness of one third that of the angle parent material, and there is evidence that in some cases the holes may not have been fully plugged. As a result the fatigue durability of the reworked components P/N 85350927-107SP and -108SP, is unknown and more frequent inspections are required.
As the affected aircraft can only be narrowed down to the block of serial numbers specified above, all aircraft within this block must be treated as if they were fitted with the suspect fairing angles.
Amendment 1 is issued in response to a revision of the related Country of Origin AD which introduces the Model 315 to the Applicability.
Overview
The Civil Aviation Regulations 1998, which were enacted to provide comprehensive rules governing civil aviation safety in Australia, include specific airworthiness directives aimed at ensuring the safety of aircraft operations. Among these is Part 39 - 105, which pertains to directives issued by the Civil Aviation Safety Authority. The AD/DHC-8/28 Amendment 1, issued in 1995, targets Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes, specifically Models 311 and 315 within a certain serial number range. This directive was introduced to address a safety concern identified with underwing fairing angles made from titanium, which were reworked during manufacture. These reworked angles had welds with significantly lower hardness than the parent material, leading to uncertainty about their fatigue durability. The policy objective is to ensure these angles are inspected more frequently to prevent potential failure, thereby maintaining the airworthiness and safety of the aircraft.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates the Civil Aviation Safety Authority's Schedule of Airworthiness Directives for Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes. This particular directive, AD/DHC-8/28 Amendment 1, pertains to the underwing fairing angles of DHC-8 aircraft, Models 311 and 315, within the serial number range of 240 through 279. It requires an inspection of the rear face of the left and right hand underwing fairing angles for cracks, following the instructions outlined in de Havilland Service Bulletin A8-53-46 Rev A. Compliance with this directive necessitates an inspection before 6930 flights or within 100 flights from 7 June 1993, whichever is later, and re-inspections at intervals not exceeding 6930 flights until the angles are replaced. The amendment, effective from 9 November 1995, responds to a revision in the related Country of Origin AD by including Model 315 within the scope of applicability. If an angle is replaced, the inspection requirement reverts to the standard aircraft's threshold of 40000 flights and a repeat interval of 8194 flights.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105 under the Civil Aviation Safety Authority Schedule of Airworthiness Directives, address the maintenance requirements for Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes. The AD/DHC-8/28 Amendment 1 pertains to underwing fairing angles and is applicable to DHC-8 aircraft, Models 311 and 315, with serial numbers ranging from 240 to 279. According to section 12/95, these aircraft must undergo an inspection of the rear face of the left and right underwing fairing angles for cracks. This inspection is to be conducted in accordance with Part A of the Accomplishment Instructions in de Havilland Service Bulletin A8-53-46 Rev A.
The regulations impose several obligations on the parties involved. Firstly, the inspection must be carried out before the aircraft reaches 6930 flights or within 100 flights from 6 July 1993, whichever is later. Once the initial inspection is completed, subsequent inspections must be performed at intervals not exceeding 6930 flights until the angles are replaced. The requirement is to ensure that the angles are continuously monitored for structural integrity, given that some titanium fairing angles were reworked during the manufacturing process and may not meet the required fatigue durability.
Failure to comply with the inspection requirements set out in the AD/DHC-8/28 Amendment 1 can result in significant consequences. The Civil Aviation Regulations do not explicitly state the penalties for non-compliance, but generally, breaches of such directives can lead to severe civil or criminal liabilities under broader aviation safety laws. Non-compliance may result in penalties that could include fines or, in more severe cases, criminal charges. The exact penalties would depend on the specific breaches and the interpretation of the broader regulatory framework governing civil aviation safety.