COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Short SD3-60 Series Aeroplanes
AD/SD3-60/24 Propeller Blade Model M10876K 11/87
DM
Applicability: All Shorts SD3-60 aircraft fitted with Hartzell Model HC-B5HP-3( )/M10876K propellers.
Requirement: Action in accordance with Shorts SD3-60 Service Bulletin No SD360-61-06.
Note: Hartzell Service Bulletin No 154 refers.
Compliance: (i) Blades with 0 to 3000 hours time in service since new will require inspection of the blade internal bearing hole in accordance with Hartzell Service Bulletin 136D prior to completing 3000 hours total time in service.
(ii) For blades in excess of 3000 hours time in service and which have accumulated in excess of 300 flights since the last inspection in accordance with Hartzell Service Bulletin 136D are required to be reinspected in accordance with Hartzell Service Bulletin 136D prior to accumulating an additional 100 flights.
(iii) Blades which have accumulated less than 300 flights are required to be reinspected in accordance with Hartzell Service Bulletin 136D at 300 flights or the accumulation of 100 additional flights from 24 August 1987 whichever is the greater.
(iv) Following completion of initial inspection as required by sub-paras (i), (ii) or (iii), as applicable, all blades must be inspected in accordance with Hartzell Service Bulletin 136D at each and every subsequent 300 flight interval until retired from service.
(v) All model M10876K blades are to be retired from service by 31 March 1988.
Background: There have been a limited number of M10876K blade shank cracks with one blade separating from an aircraft. Cause of the shank crack appears to be related to minor corrosion pits located in the blade internal bearing hole. Blade bearing hole corrosion has already been addressed by Hartzell Service Bulletin 136D. A replacement blade M10876ASK will be available from mid-August 1987.
Overview
The Civil Aviation Regulations 1998, enacted by the Parliament of Australia, encompass a broad range of safety standards and requirements for civil aviation. One particular instrument under this legislation, F2006B06868, pertains to the maintenance and airworthiness of specific aircraft models, particularly focusing on the Shorts SD3-60 Series Aeroplanes equipped with Hartzell Model HC-B5HP-3( )/M10876K propellers. This legislation was introduced to address the identified issue of blade shank cracks in M10876K propeller blades, which have been linked to minor corrosion pits in the blade's internal bearing hole, posing a safety risk. The objective of this directive is to ensure that all affected aircraft adhere to a specific inspection and maintenance schedule to mitigate these risks and enhance the safety of air travel.
The directive outlines a comprehensive inspection protocol, requiring different actions based on the service hours and flight count of the blades. It mandates initial and subsequent inspections at specified intervals, and it also sets a retirement date for all M10876K blades, aiming to replace them with the newly available M10876ASK blades to further enhance safety. This legislative instrument is a critical part of the overarching policy to maintain the highest standards of aviation safety in Australia.
Scope and Application
The Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates the application of Airworthiness Directives (AD) to ensure the safety of aviation operations. This particular AD/SD3-60/24 applies to all Shorts SD3-60 series aeroplanes equipped with Hartzell Model HC-B5HP-3/M10876K propellers, necessitating compliance with the directives outlined in the Shorts SD3-60 Service Bulletin No SD360-61-06. Additionally, Hartzell Service Bulletin No 154 is referenced for further guidance. The directive includes specific requirements for the inspection and reinspection of propeller blades to prevent the occurrence of blade shank cracks, which have previously led to blade separation from the aircraft, potentially due to corrosion in the blade internal bearing hole. The compliance schedule dictates that blades with varying service hours and flight counts must undergo inspections and reinspections at specified intervals, culminating in the retirement of all M10876K blades by 31 March 1988.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 105, establish a schedule of airworthiness directives (AD) that govern the maintenance and operation of certain aircraft. Section AD/SD3-60/24 pertains to the Short SD3-60 Series Aeroplanes fitted with Hartzell Model HC-B5HP-3( )/M10876K propellers. This directive outlines specific requirements and procedures for the inspection and eventual retirement of the M10876K propeller blades to mitigate the risk of shank cracks and blade separation.
The main operative sections of this directive detail the required inspections and reinspections of M10876K propeller blades based on their time in service and flight hours. According to the directive, blades with 0 to 3000 hours of service must be inspected prior to reaching 3000 hours. For blades that have been in service for over 3000 hours and have accumulated more than 300 flights since their last inspection, reinspection is required before they accumulate an additional 100 flights. Blades that have accumulated fewer than 300 flights must be reinspected at 300 flights or after 100 additional flights from a specified date, whichever is later. After the initial inspection, all blades must undergo inspection at every subsequent 300-flight interval until they are retired from service.
Entities governed by this AD must comply with the inspection and reinspection requirements outlined in the directive. This includes performing inspections in accordance with Hartzell Service Bulletin 136D and ensuring that all blades are either inspected or reinspected as required, based on their time in service and flight hours. Additionally, all M10876K blades must be retired from service by 31 March 1988.
Failure to comply with the AD/SD3-60/24 may result in civil or criminal consequences. The Civil Aviation Regulations 1998 provide for enforcement actions against entities that do not adhere to airworthiness directives. Penalties for non-compliance can include fines, suspension or revocation of airworthiness certificates, and other regulatory actions. While the specific penalties are not detailed in the directive itself, they are outlined in the broader regulatory framework provided by the Civil Aviation Act 1988 and associated regulations.