COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 107 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Propellers - Variable Pitch - Dowty Rotol
AD/PR/32 Blade Pitch Seizure 4/97
Applicability: All R/354/4-123-F/13, R354/4-123-F/20, R375/4-123-F/21, R389/4-123-F/25,
R389/4-123-F/26 or R390/4-123-F/27 propellers fitted to SAAB 340 A or B series aircraft.
Requirement: Modify or de-modify (as applicable) the propeller pitch change mechanism in accordance with Dowty Aerospace Mandatory SB SF340-61-88 dated Jan 23/97.
Note: UK CAA AD 002-11-96 dated 2 November, 1996, refers.
Compliance: Unless previously carried out, incorporate as specified in the Requirement Document paragraph D.
This Airworthiness Directive becomes effective on 27 March 1997.
Background: The manufacturer has advised that during ground running a propeller which had recently been modified to SB SF340-61-79 status, suffered a seizure of the propeller pitch change. This occurred when the slide block, attached to the crosshead by coiled springs, became detached and allowed the crosshead to turn and contact the blade root inner sleeves which then locked the propeller blades in a fixed position.
Overview
The Civil Aviation Regulations 1998, specifically Part 39 - 107, was enacted to regulate the airworthiness of aircraft and related equipment, ensuring safety in civil aviation. The legislation was introduced to address the need for standardised airworthiness directives to maintain and improve safety standards in the aviation industry. This legislative instrument was issued by the Commonwealth of Australia, with the policy objective of ensuring that aircraft and their components meet the necessary safety requirements. In this particular case, the directive targets the modification or de-modification of the propeller pitch change mechanism for specific types of Dowty Rotol propellers used on SAAB 340 A or B series aircraft to prevent blade pitch seizure. This directive was implemented to mitigate the risk of propeller malfunction that could potentially lead to catastrophic failures during flight.
This Airworthiness Directive aims to mandate modifications to the pitch change mechanism of specified propellers to prevent pitch seizure, a condition where the propeller blades lock in a fixed position, which could result in significant safety hazards. The directive references a UK Civil Aviation Authority Airworthiness Directive and a Dowty Aerospace Mandatory Service Bulletin to detail the required modifications. By issuing this directive, the Civil Aviation Safety Authority seeks to ensure compliance with the specified modifications to enhance the safety and reliability of the affected propellers, thereby protecting the integrity of civil aviation operations within Australia.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39, governs the airworthiness of aircraft and related components, with the Airworthiness Directive AD/PR/32 addressing blade pitch seizure issues for certain Dowty Rotol propellers. This directive applies to all R/354/4-123-F/13, R354/4-123-F/20, R375/4-123-F/21, R389/4-123-F/25, R389/4-123-F/26, or R390/4-123-F/27 propellers installed on SAAB 340 A or B series aircraft. The directive mandates that these propellers be modified or de-modified as necessary to comply with Dowty Aerospace Mandatory Service Bulletin SF340-61-88 dated January 23, 1997. The requirement is to address the specific issue of propeller pitch change mechanism failure, as referenced by the UK Civil Aviation Authority's Airworthiness Directive 002-11-96 dated November 2, 1996. Compliance with this directive is mandatory, and the modifications must be incorporated as specified in the Requirement Document paragraph D unless they have already been performed. This Airworthiness Directive came into effect on March 27, 1997, following reports of propeller pitch seizures during ground operations after modifications to the blade pitch change mechanism.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 107, establish the requirements for ensuring the airworthiness of propellers fitted to certain aircraft. Under this regulation, Section AD/PR/32 addresses the issue of blade pitch seizure in Dowty Rotol variable pitch propellers used in SAAB 340 A or B series aircraft. This section requires that any affected propellers be modified or de-modified according to Dowty Aerospace's Mandatory Service Bulletin SF340-61-88 dated January 23, 1997, as referenced in UK CAA AD 002-11-96 dated November 2, 1996. The modification must be carried out in accordance with the Requirement Document, specifically paragraph D, unless such modifications have already been implemented. This directive became effective on March 27, 1997.
The obligations imposed by this legislation on the relevant parties, such as aircraft operators and maintenance organisations, include ensuring that all specified propellers are inspected and, if necessary, modified to comply with the outlined requirements. The modifications must be performed by certified personnel and documented properly to maintain the airworthiness of the aircraft. Operators must also ensure that all modifications are completed before the propellers are used in flight. This is to prevent the identified risk of blade pitch seizure, which could lead to a dangerous situation during flight.
Failure to comply with the requirements set out in Section AD/PR/32 of the Civil Aviation Regulations 1998 may result in serious safety issues. The legislation does not explicitly detail the penalties for non-compliance, but general provisions within the Civil Aviation Act 1988 may apply. Such non-compliance could lead to enforcement actions by the Civil Aviation Safety Authority (CASA), including fines and potential grounding of the aircraft until the issue is resolved. The severity of the penalties can vary, but they are intended to ensure strict adherence to the airworthiness directives to maintain safety standards in aviation.