AD/DH 60/3 Amdt 1 - Datum Bolts

Overview

The Civil Aviation Regulations 1998, amended through the legislative instrument F2006B08890, was enacted to ensure the ongoing airworthiness and safety of civil aircraft within Australia. The legislation, administered by the Civil Aviation Safety Authority (CASA), addresses specific technical and maintenance requirements for certain aircraft models to mitigate potential safety risks. The policy objective is to enhance the safety standards of civil aviation by enforcing precise airworthiness directives, which include mandatory inspections and repairs on aircraft parts, such as datum bolts in De Havilland DH 60 (Moth) series aeroplanes. This particular amendment, issued in 1998, was introduced to respond to identified safety concerns regarding the datum bolts at fuselage joint “E”, ensuring compliance with British Aerospace Technical News Sheet CT (Moth) No.28 Issue 2 and UK CAA AD 002-10-97. The requirement mandates inspections and necessary replacements within a specified timeframe, underscoring the commitment to maintaining high safety standards in civil aviation.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, under the Civil Aviation Safety Authority’s Schedule of Airworthiness Directives, governs the maintenance and airworthiness of certain aircraft, including the De Havilland DH 60 (Moth) Series Aeroplanes. This legislative instrument applies to all DH 60 Moth aircraft models except the 60G and 60M, ensuring they adhere to safety standards critical for the operation of these historic aircraft. The directive mandates actions in line with the British Aerospace Technical News Sheet CT (Moth) No.28 Issue 2 and references the UK Civil Aviation Authority AD 002-10-97. Compliance with this directive is necessary within 25 hours of time in service after 10 September 1998, or before 10 December 1998, whichever comes first. This requirement ensures that specific fuselage joints, including datum pins, are inspected and, if necessary, replaced to meet the stipulated material specifications. Any failure to comply with this directive may result in the aircraft being deemed non-airworthy, impacting the operators' ability to legally fly these aircraft.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, under the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, addresses the maintenance and inspection requirements for De Havilland DH 60 (Moth) Series Aeroplanes. The particular amendment in focus is AD/DH 60/3 Amendment 1, which pertains to datum bolts (Section 10/98). This directive applies to the DH60 models, excluding the 60G and 60M Moth aircraft. The primary requirement of this amendment is that aircraft operators must take action in accordance with British Aerospace Technical News Sheet CT (Moth) No.28 Issue 2, referencing UK CAA AD 002-10-97. Operators must ensure compliance within 25 hours of the aircraft being in service after 10 September 1998, or before 10 December 1998, whichever comes first. The obligations imposed by this directive include a comprehensive inspection of the bolts at fuselage joint “E” to ascertain their material specifications. This inspection is critical as Moth aircraft utilise special bolts at certain fuselage joints that act as datum pins when rigging the aircraft longitudinally. These bolts, although visually similar, have differing material specifications. Operators must conduct this inspection and make any necessary replacements to ensure the integrity and safety of the aircraft. Additionally, this amendment allows for the use of A25 bolts as a substitute for the obsolete specification AGS. 749 bolts, providing a practical solution for maintaining compliance. Failure to comply with the requirements set forth in this directive can result in severe consequences. The regulations mandate that operators must adhere to the stipulated timeframes and procedures for inspection and replacement of the specified bolts. Non-compliance may lead to the aircraft being deemed unairworthy, potentially resulting in grounding until the required actions are completed. This not only poses a risk to the safety of the passengers and crew but also could lead to substantial regulatory penalties, including fines and legal actions. The specific penalties for non-compliance are not detailed in the text but are generally enforced under the broader civil aviation regulatory framework, which can include both financial penalties and operational restrictions. The directive's background indicates that Moth aircraft have specific structural requirements, and the datum bolts at joint “E” are critical for maintaining the aircraft's longitudinal rigging. Amendment 1 was introduced to address an additional inspection and replacement requirement for the bolts on the opposite side of the aircraft from the datum bolts. This amendment was issued in response to Issue 2 of the Requirement document, which mandates a one-time inspection and replacement, where necessary, of these specific bolts. This proactive measure aims to enhance the safety and reliability of the Moth aircraft by ensuring that all datum bolts meet the required material specifications, thus maintaining the structural integrity of the aircraft.