COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Propellers - Variable Pitch - McCauley
AD/PMC/43 Blade Shank Corrosion 8/89
Applicability: All McCauley Hubs P/No 41D5926 with blade P/No SS-135-6 or Hub P/No D-1093 with blade P/No SS-135-6M or SS-138-6.
Requirement: Disassemble and inspect the hub and blade shank for fatigue cracks using an approved magnetic particle inspection technique.
Note 1. The technique detailed in CAO 108-8 is an approved technique. Note 2. FAA AD 54-12-02 refers.
Compliance: Unless already accomplished; by 31 August 1989. Thereafter reinspect at intervals not exceeding 100 hours time in service.
Background: To ensure fatigue cracking is detected before loss of a blade occurs, a recurring magnetic particle inspection is required. Affected propellers are fitted to Boeing Stearman aircraft and may be fitted to other older style aircraft.
Overview
The Civil Aviation Regulations 1998, under Part 39 - 107, incorporates the Civil Aviation Safety Authority's (CASA) schedule of airworthiness directives, including AD/PMC/43 concerning blade shank corrosion in McCauley propellers. This legislation was enacted to address the problem of undetected fatigue cracks in certain McCauley propellers, which could lead to catastrophic failure during flight. The directive applies specifically to McCauley hubs with particular blade part numbers and mandates that these components be disassembled and inspected for fatigue cracks using an approved magnetic particle inspection technique. The policy objective is to ensure that such inspections are carried out regularly to prevent any blade loss, thereby enhancing aviation safety.
This airworthiness directive is part of the broader regulatory framework established by the Australian Government to ensure the safety and reliability of civil aviation operations. Compliance with AD/PMC/43 is mandatory for all affected propellers, requiring initial inspection by a specified deadline and subsequent reinspections at intervals not exceeding 100 hours of service time. The directive references FAA AD 54-12-02, highlighting the importance of adhering to internationally recognised safety standards.
Scope and Application
The Civil Aviation Safety Authority's Airworthiness Directives, specifically AD/PMC/43, pertain to the inspection of certain McCauley propellers used in aircraft, particularly those fitted to Boeing Stearman aircraft and potentially to other older style aircraft. This directive applies to McCauley hubs with specific part numbers (41D5926, D-1093) paired with blades numbered SS-135-6, SS-135-6M, or SS-138-6. The requirement is to disassemble and inspect the hub and blade shank for fatigue cracks using an approved magnetic particle inspection technique, as detailed in CAO 108-8, with compliance mandated by 31 August 1998. This inspection must be repeated at intervals not exceeding 100 hours of time in service thereafter to ensure the continued airworthiness of the aircraft. The directive is applicable across the Commonwealth of Australia, enforcing safety standards set by the Civil Aviation Regulations 1998 and is consistent with corresponding directives issued by the Federal Aviation Administration (FAA) under AD 54-12-02.
Key Provisions
The Civil Aviation Regulations 1998, under Part 39 - 107, establish specific Airworthiness Directives (AD) that are crucial for maintaining the safety and airworthiness of aircraft. In particular, AD/PMC/43 focuses on the inspection of blade shank corrosion for certain McCauley propellers (sections 1-4). This directive applies to all McCauley hubs with specific part numbers, namely P/No 41D5926 with blade P/No SS-135-6, or P/No D-1093 with blades P/No SS-135-6M or SS-138-6. The directive mandates that these components be disassembled and inspected for fatigue cracks using an approved magnetic particle inspection technique, as outlined in CAO 108-8 (section 2). Additionally, it references FAA AD 54-12-02 for further guidance (section 2, Note 2).
The obligations imposed by this directive require operators to ensure that the specified propellers are inspected according to the stipulated timeframes and methods. The inspection must be carried out unless it has already been completed. Specifically, the initial inspection must be completed by 31 August 1989. Following this, recurring inspections must be performed at intervals not exceeding 100 hours of time in service (section 3). This periodic inspection is crucial to prevent the occurrence of fatigue cracks, which could lead to catastrophic failure of the propeller blades during operation.
Failure to comply with the requirements outlined in AD/PMC/43 can result in significant consequences. The regulations do not explicitly state the penalties or consequences for non-compliance in the provided text; however, non-compliance with airworthiness directives generally results in the aircraft being deemed unairworthy. This could lead to enforcement actions by the Civil Aviation Safety Authority (CASA), including potential grounding of the aircraft until the necessary inspections and repairs are completed. Additionally, operators may face fines, legal action, and reputational damage, which could further impact their ability to operate commercially.