COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Eurocopter AS 355 (Twin Ecureuil) Series Helicopters
AD/AS 355/31 Tail Rotor Gearbox Casing 1/88
Applicability: All model AS 355 Series helicopters.
Requirement: 1. Inspect the tail rotor gearbox casing in accordance with Para 1C(2) of SB No 05.18.
2. Inspect and modify the tail rotor gearbox in accordance with Para 1C(3) of SB No 05.18.
Compliance: For Para 1: Within 50 hours time in service after 18 November 1987 and thereafter at intervals not exceeding 50 hours time in service, until modification AMS 350A07- 8535 (polishing blend radii) is incorporated. After modification, inspect at intervals not exceeding 400 hours time in service.
For Para 2: Prior to exceeding 1100 hours total time in service or within 100 hours time in service after 18 November 1987, whichever is the later.
Background: The manufacturer has received reports of cracking in the blade horn support yoke radius just inboard of where the tail rotor control bellcrank pivot bolt is located.
Overview
The Civil Aviation Regulations 1998, as part of their ongoing commitment to aviation safety, introduced specific directives through the Civil Aviation Safety Authority (CASA) to address identified safety concerns with the Eurocopter AS 355 (Twin Ecureuil) Series helicopters. One such directive, AD/AS 355/31, was introduced in 1988 in response to reports of cracking in the blade horn support yoke radius just inboard of the tail rotor control bellcrank pivot bolt. This directive aims to mitigate the risk of in-flight failures by mandating rigorous inspection and modification of the tail rotor gearbox casing, ensuring the continued airworthiness of these helicopters and protecting the safety of those on board.
The policy objective behind this directive is to ensure the highest possible safety standards within the Australian aviation industry by requiring regular inspections and modifications as specified by the CASA. By mandating these checks at defined intervals, the regulations aim to preemptively address potential mechanical failures, thereby enhancing the overall safety of air travel.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105 under the Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to all Eurocopter AS 355 Series helicopters operating within Australian airspace. This legislation mandates that operators of these helicopters must adhere to specific inspection and modification requirements concerning the tail rotor gearbox casing to ensure continued airworthiness and safety. The directive is applicable to all model AS 355 Series helicopters, and the requirements outlined must be met to maintain compliance with Australian aviation safety standards.
The regulation stipulates two main requirements: first, the tail rotor gearbox casing must be inspected in accordance with Paragraph 1C(2) of Service Bulletin No 05.18. This inspection must occur within 50 hours of time in service after 18 November 1987 and then at intervals not exceeding 50 hours until a specified modification is incorporated. Following the incorporation of the modification AMS 350A07-8535 (polishing blend radii), inspections must be conducted at intervals not exceeding 400 hours of time in service. Second, the tail rotor gearbox must be inspected and modified in accordance with Paragraph 1C(3) of Service Bulletin No 05.18, with the requirement to be completed before the helicopter exceeds 1100 hours of total time in service or within 100 hours of time in service after 18 November 1987, whichever is the later. These provisions are essential to address the reported issues of cracking in the blade horn support yoke radius, ensuring the safety and reliability of the helicopters in operation.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandate the application of Airworthiness Directives (AD) for Eurocopter AS 355 (Twin Ecureuil) Series helicopters. One such directive, AD/AS 355/31, pertains to the tail rotor gearbox casing (section 1/88). This directive applies to all model AS 355 Series helicopters and includes two main requirements: the inspection of the tail rotor gearbox casing and the inspection and modification of the tail rotor gearbox. The inspections and modifications must be carried out in accordance with the specified paragraphs of Service Bulletin No 05.18 (section 1C(2) and 1C(3)).
Operators and owners of the affected helicopters must ensure compliance with these requirements. For the inspection of the tail rotor gearbox casing, the compliance period begins 50 hours after 18 November 1987 and must be repeated at intervals not exceeding 50 hours until the modification AMS 350A07-8535 (polishing blend radii) is implemented. After the modification, inspections must occur at intervals not exceeding 400 hours. For the inspection and modification of the tail rotor gearbox, the compliance period is either prior to exceeding 1100 hours of total time in service or within 100 hours after 18 November 1987, whichever is later.
Failure to comply with these Airworthiness Directives can lead to serious consequences. The Civil Aviation Safety Authority (CASA) may take enforcement actions against operators and owners who do not adhere to the specified inspection and modification requirements. Such non-compliance could result in the grounding of the aircraft until the required inspections and modifications are performed. Additionally, operators may face penalties for operating an aircraft that does not meet airworthiness standards, potentially leading to civil or criminal charges if the non-compliance results in safety incidents. The exact penalties for breaches are not specified in the legislative text, but they can include fines, imprisonment, or both, depending on the severity of the breach and its impact on aviation safety.