COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Pratt and Whitney Canada Turbine Engines - PT6A Series
AD/PT6A/27 Compressor Bleed Off Valve 4/97
Applicability: All Pratt and Whitney Canada (PWC) PT6A engines as detailed by serial number in the following PWC Service Bulletins (SB): SB 1538 Rev.3; SB 3344 Rev.1; SB 4204; SB 12134 Rev.1; SB13287 Rev.1; SB 14251 Rev.1.
Requirement: To prevent the possible malfunction of the compressor bleed off valve resulting in a reduction of required engine power or an engine surge event:
- Inspect the bleed off valve to determine the supplier code. If the supplier code is “8070”, inspect the bleed off valve in accordance with PWC SB 1538 Rev. 3; SB 3344 Rev.1; SB 4204; SB 12134 Rev.1; SB 13287 Rev.1 or SB 14251 Rev.1 as applicable by engine model.
2. If the supplier code is not “8070” or the bleed off valve has been re-identified to “RE71”, no further action is required.
Note: Transport Canada Airworthiness Directive CF-96-24 refers.
Compliance: Effective 27 March 1997: Unless previously accomplished; within 100 hours time in service or prior to 30 May 1997, whichever occurs first.
Background: This directive has been issued to require certain compressor bleed off valves to be inspected. The requirement follows advice of movement in the valve guide shaft pin can result in fracture of the cotter pin and possible jamming of the valve. Failure of the valve may result in the loss of required engine power or an engine surge.
Overview
The Civil Aviation Regulations 1998, as amended, address a specific safety concern associated with Pratt and Whitney Canada (PWC) PT6A series turbine engines. This legislation was enacted to prevent potential malfunctions of the compressor bleed off valve, which could lead to a reduction in engine power or engine surge events. The requirement is outlined in the Airworthiness Directive AD/PT6A/27, issued by the Civil Aviation Safety Authority (CASA) in response to identified risks highlighted by Transport Canada. The policy objective is to ensure the airworthiness of the affected engines through mandated inspections and maintenance procedures, aiming to mitigate the risk of in-flight engine failures. Compliance with this directive is mandatory, with inspections to be completed within specific timeframes to ensure the safety of aircraft operations.
Scope and Application
The Civil Aviation Regulations 1998, as amended, apply to all Pratt and Whitney Canada (PWC) PT6A engines specified by serial numbers within the relevant PWC Service Bulletins. This regulation mandates that the compressor bleed off valve in these engines must be inspected to determine the supplier code. If the supplier code is "8070", the bleed off valve must be further inspected as per the applicable PWC Service Bulletins depending on the engine model. This inspection is a critical safety measure designed to prevent a potential malfunction of the compressor bleed off valve, which could lead to a reduction in engine power or an engine surge event. The regulation specifies a compliance timeline, mandating that the inspection must be completed within 100 hours of the engine being in service or by 30 May 1997, whichever comes first. No further action is required if the supplier code is not "8070" or if the bleed off valve has been re-identified to "RE71". This directive is rooted in safety considerations, ensuring that the operation of these engines maintains the highest standards of reliability and safety as overseen by the Civil Aviation Safety Authority.
Key Provisions
The Civil Aviation Regulations 1998, specifically Part 39 - 106, mandate that Pratt and Whitney Canada (PWC) PT6A series turbine engines undergo inspection of their compressor bleed off valves (s. 1). This applies to all PT6A engines identified by specific serial numbers detailed in Pratt and Whitney Canada Service Bulletins (SBs) 1538 Rev.3; 3344 Rev.1; 4204; 12134 Rev.1; 13287 Rev.1; and 14251 Rev.1. The primary requirement is to inspect the bleed off valve to determine the supplier code (s. 2). If the supplier code is identified as “8070”, further inspection is necessary in accordance with the specified PWC Service Bulletins, depending on the engine model. If the supplier code is not “8070” or the bleed off valve has been re-identified as “RE71”, no further action is required.
These regulations impose specific obligations on the parties involved. Operators and owners of PT6A engines must ensure that the compressor bleed off valves are inspected within the stipulated timeframe. The inspections must be performed by qualified personnel, and any necessary actions must be completed in accordance with the specified Pratt and Whitney Canada Service Bulletins. Compliance must be achieved either within 100 hours of the engine’s time in service or before 30 May 1997, whichever comes first (s. 3). Failure to comply with these directives may result in the engine being deemed unairworthy, leading to potential grounding of the aircraft.
Non-compliance with these airworthiness directives can lead to significant consequences. The Civil Aviation Safety Authority (CASA) can impose penalties and sanctions on operators and owners who fail to adhere to the inspection and maintenance requirements outlined in the regulations. Under Australian law, serious breaches may result in criminal charges, leading to substantial fines and imprisonment for individuals responsible for the oversight of the non-compliant engines. Additionally, CASA may issue enforcement actions, including the suspension or revocation of airworthiness certificates, which could severely impact the operational capabilities of the aircraft in question. The specific penalties for non-compliance are not detailed in the text, but they can include fines and imprisonment as stipulated under broader aviation safety regulations.