COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Eurocopter AS 350 (Ecureuil) Series Helicopters
AD/ECUREUIL/42
Amdt 1
Servo Control Securing Screw 7/88 TX
Applicability: All AS350 helicopters fitted with Dunlop servo control assemblies.
Requirement: A. Unless already accomplished in accordance with this Directive, remove one at a time all 5 mm diameter set screws P/N BS4168 attaching the servo block to the body of the actuator. Before refitting used screws check screw strength using a threaded test block or nut and appropriate spacer and applying 4.5 Nm (40 in lbs) torque proof load.
B. Unless already accomplished in accordance with this Directive, remove from service all subject screws marked “HK 129".
C. Check torque all 5 mm screws attaching end fittings.
D. If any screw is found failed all screws fitted to that end fitting or servo block must be replaced.
E. Quarantine all screws not refitted. Report details including location in servo block of broken screw, servo S/N, TTIS, date and place of servo last O/H to nearest Airworthiness office by telephone for on-forwarding to CO Canberra Attn FWRM.
Note: Ensure all screws do not bottom out in the servo body.
Compliance: A. Before further flight after 6 May 1988.
B. Within 25 hrs CTIS after inspection.
C. Within 25 hrs CTIS after 16 May 1988.
D. Before further flight.
E. Within 48 hours of discovery.
Background: While investigating the cause of a main rotor vibration, screw P/N BS 4168 attaching the servo block to the body was found sheared in two of the main rotor assemblies.
Examination of the screws revealed failure was caused by hydrogen embrittlement. As batch details of these screws cannot be confirmed a fleet inspection was required. To urgently advise all operators of this problem a telex AD was issued. This amendment is raised to ensure servo end fitting screws which are of the same type are correctly torqued.
Overview
The Civil Aviation Regulations 1998, enacted by the Parliament of the Commonwealth of Australia, are designed to ensure the safety and reliability of civil aviation operations within the country. One particular legislative instrument under this Act, F2006B09349, pertains to the Airworthiness Directives (AD) concerning the Eurocopter AS 350 (Ecureuil) Series Helicopters. This directive, AD/ECUREUIL/42 Amendment 1, addresses the issue of servo control securing screws which were found to be susceptible to failure due to hydrogen embrittlement, leading to main rotor vibrations. The policy objective of this directive is to ensure the continued airworthiness of the affected helicopters by mandating specific maintenance actions, including the removal, inspection, and replacement of the affected screws, as well as the reporting of any failures to the relevant authorities. Compliance with these directives is crucial to maintain safety standards and prevent potential in-flight failures.
Scope and Application
The Civil Aviation Regulations 1998, specifically PART 39 - 105 concerning the Civil Aviation Safety Authority, mandates the application of Airworthiness Directives (AD) to ensure the safety of aircraft operations within Australia. The AD/ECUREUIL/42 Amendment 1 pertains to Eurocopter AS 350 (Ecureuil) Series Helicopters, focusing on the servo control securing screw, and applies to all AS350 helicopters equipped with Dunlop servo control assemblies. This legislation is geographically applicable throughout Australia, overseen by the Commonwealth of Australia, and its implementation is critical for the continued airworthiness and safety of the specified helicopter models. The directive mandates several specific actions, including the removal and inspection of certain screws, replacement of failed components, and reporting mechanisms to ensure compliance. The directive also provides timelines for the completion of these tasks, with strict adherence required to maintain the safety standards set forth by the Civil Aviation Safety Authority. Any failure to comply with these requirements could potentially compromise the operational safety of the affected aircraft.
Key Provisions
The Civil Aviation Regulations 1998, Part 39 - 105, mandates the issuance of Airworthiness Directives (ADs) to ensure the safe operation of aircraft. Specifically, AD/ECUREUIL/42 Amendment 1 focuses on the Eurocopter AS 350 (Ecureuil) Series Helicopters, addressing the issue of the servo control securing screw. The directive applies to all AS350 helicopters equipped with Dunlop servo control assemblies (Section A). The primary requirements of this directive include the removal of specific set screws, checking the torque of certain screws, and replacing any failed screws to prevent further issues (Sections B-E). Additionally, operators must quarantine screws that are not refitted and report any incidents of screw failure to the nearest Airworthiness office within a specified timeframe (Section E).
Operators and entities governed by this directive must ensure compliance with the outlined procedures. This involves inspecting and potentially replacing screws to mitigate the risk of hydrogen embrittlement, a condition that was found to cause failure in the screws attaching the servo block to the body of the actuator. All actions must be completed before further flight and within specific time frames as stipulated by the directive. The directive also necessitates thorough documentation and reporting of any instances of screw failure, including details such as the location of the broken screw, the serial number of the servo, and the date and place of the last overhaul (Section E).
Failure to comply with the requirements set out in AD/ECUREUIL/42 Amendment 1 may result in serious safety implications, including the potential for continued operation of a helicopter with compromised structural integrity. While the Civil Aviation Regulations do not explicitly detail the penalties for non-compliance with specific ADs, general regulations under the Civil Aviation Act 1988 provide for fines and potential imprisonment for breaches of safety regulations. Specifically, the maximum penalties can include fines of up to $330,000 for corporations and $66,000 for individuals, along with imprisonment terms of up to five years. Additionally, ongoing non-compliance could lead to the grounding of the affected aircraft until the required actions are completed, further impacting operational capabilities and safety.