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-8/23
Amdt 3
NLG Upper Drag Strut Trunnion Fittings 11/95
Applicability: Model DHC-8, Series 100 and 300, serial numbers 003 through 395, except 011, 362, and 391, and which have accumulated more than 500 flight cycles.
Requirement: Action in accordance with the Accomplishment Instructions contained in de Havilland ASB A8-53-40 Revision A:
- Visually inspect, in-situ, the drag strut trunnion fittings for cracks, and torque check all the fasteners securing the fittings.
If cracks are found on either fitting, replace both fittings with serviceable fittings prior to further flight.
2. (a) During the initial inspection, any fasteners found loose by the torque check must be replaced with new parts.
(b) During subsequent inspections, any fastener found loose by the torque check must be tightened properly.
3. For aircraft already fitted with de Havilland Modification 8/1880, re-instate (or commence) the repetitive inspection required by parts 1 and 2 above in accordance with the schedule below:
(a) If the aircraft has 900 or more flight cycles since the last inspection (or incorporation of Modification 8/1880), the next inspection (or the initial inspection) shall be performed within the subsequent 100 flight cycles.
(b) If the aircraft has less than 900 flight cycles since the last inspection (or incorporation of Modification 8/1880), the next inspection (or the initial inspection) shall be performed at or before the due date of the actual 1000 flight cycle interval, determined from the last inspection (or incorporation of Modification 8/1880).
Incorporation of de Havilland Modification 8/2139 (Introduction of New Trunnion Fittings and Fasteners for Drag Link of Nose Landing Gear) provides terminating action to the inspection requirements of this Directive. De Havilland Service Bulletin 8-53-49, dated 30 June 1995, provides approved instructions to incorporate Modification 8/2139 for aircraft not incorporating this modification during production.
Note: Transport Canada AD CF-92-18R3 refers.
Compliance: Initially, within 500 flight cycles after 12 November 1992, unless already accomplished during the last 500 flight cycles; and thereafter at intervals not to exceed 1000 flight cycles.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
The compliance of the initial issue of this Directive remains unchanged. This Amendment is effective from 12 October 1995.
Background: Cracks have been found in the two trunnion fittings that retain and support the nose landing gear upper drag strut. Investigations have indicated that this cracking problem is caused by ground handling loads that appear to be higher than originally predicted. This condition may be further aggravated by loose fasteners.
Amendment 1 introduced optional terminating action. Amendment 2 rescinded the terminating action provided by an earlier issue of the AD. This action was prompted by reports that, due to bolt head gapping, installation difficulties have been encountered during incorporation of Modification 8/1880 on the aircraft, resulting in improper attachment of the fitting which, in turn, may cause the bolts to lose pre- tension.
Amendment 3 is issued to introduce optional terminating action to the inspection requirements of this Directive.
Overview
The Civil Aviation Regulations 1998, as amended, are a cornerstone of Australia's regulatory framework for ensuring the safety and efficiency of civil aviation. Among these amendments, the Airworthiness Directive (AD) issued under PART 39 - 105 addresses specific safety concerns related to aircraft maintenance and operations. This particular AD, AD/DHC-8/23 Amendment 3, was introduced in response to identified issues with the upper drag strut trunnion fittings on Bombardier (Boeing Canada/De Havilland) DHC-8 Series aeroplanes. These fittings, crucial for the structural integrity of the nose landing gear, were found to be susceptible to cracks caused by ground handling loads exceeding original predictions. The directive mandates regular inspections and maintenance actions to mitigate these risks, ensuring continued airworthiness and safety for affected aircraft models.
The AD was enacted by the Civil Aviation Safety Authority (CASA) under the authority granted by the Civil Aviation Act 1988. The policy objective of this directive is to enhance aviation safety by requiring specific maintenance actions on DHC-8 Series aeroplanes to prevent structural failures that could compromise flight safety. Compliance with this directive is crucial for operators of these aircraft, as it directly impacts the safety of their operations. The directive specifies detailed inspection and maintenance procedures, including visual inspections for cracks and torque checks of fasteners, with clear intervals for these actions based on the aircraft's flight cycles. This proactive approach aims to prevent potential in-flight failures, thereby safeguarding both crew and passengers.
Scope and Application
The Civil Aviation Regulations 1998, under PART 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives, specifically address the Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes through AD/DHC-8/23 Amendment 3. This legislation applies to DHC-8 Series 100 and 300 models, with serial numbers ranging from 003 to 395, excluding 011, 362, and 391, that have accumulated more than 500 flight cycles. The directive mandates a visual inspection of the NLG upper drag strut trunnion fittings for cracks and a torque check on all securing fasteners, with specific action required if cracks are found or if any fasteners are loose. The regulations provide a detailed inspection schedule, with the next inspection required within 100 flight cycles if the aircraft has accumulated 900 or more flight cycles since the last inspection, and at or before the 1000 flight cycle interval if fewer than 900 flight cycles have passed since the last inspection. Compliance with these directives is mandatory within 500 flight cycles after the directive's issue date, with subsequent inspections required at intervals not exceeding 1000 flight cycles. This regulatory framework ensures the ongoing airworthiness of the specified aircraft models by addressing potential structural issues in the nose landing gear system.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105, includes an airworthiness directive AD/DHC-8/23 Amendment 3 (AD 2006-09178) concerning the Bombardier (Boeing Canada/De Havilland) DHC-8 Series aeroplanes. This directive applies to the DHC-8 Series 100 and 300 models, serial numbers 003 through 395, excluding 011, 362, and 391, that have accumulated more than 500 flight cycles. The primary requirement (section 1) mandates a visual inspection of the upper drag strut trunnion fittings to check for cracks and to perform a torque check on the fasteners securing these fittings. If any cracks are detected, both trunnion fittings must be replaced with serviceable parts before any further flight. Additionally, if any fasteners are found to be loose during the initial inspection, they must be replaced with new parts, whereas subsequent inspections only require the loose fasteners to be tightened properly (section 2). Aircraft that have already been fitted with de Havilland Modification 8/1880 must adhere to a repetitive inspection schedule, with inspections occurring within 100 flight cycles if the aircraft has accumulated 900 or more flight cycles since the last inspection, or at or before the 1000 flight cycle interval if it has accumulated less than 900 flight cycles since the last inspection (section 3).
The obligations imposed by this directive are clear and specific. Operators of the affected aircraft must ensure that the inspections and necessary actions are carried out as per the directive's requirements. This involves inspecting the drag strut trunnion fittings for any signs of cracking and ensuring that all fasteners are properly torqued. If any defects are found, the required corrective actions must be taken without delay. Furthermore, the directive mandates that the repetitive inspection schedule be followed strictly to maintain the airworthiness of the aircraft. The directive also references the need for incorporating de Havilland Modification 8/2139 for new trunnion fittings and fasteners, and provides approved instructions for this modification through de Havilland Service Bulletin 8-53-49.
Failure to comply with the requirements set out in AD/DHC-8/23 Amendment 3 could lead to serious consequences. The Civil Aviation Safety Authority (CASA) can enforce penalties for non-compliance with airworthiness directives. While the specific penalties are not detailed within the text of this directive, CASA can impose administrative penalties under section 175 of the Civil Aviation Act 1988, which may include fines of up to $21,000 for individuals and significantly higher amounts for corporations. Additionally, CASA may take enforcement action under section 176 of the Act, which can include the prohibition of a person from participating in the operation of an aircraft, further highlighting the seriousness of compliance with these airworthiness directives.