COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Allison Turbine Engines - 250 Series
AD/AL 250/79 Fuel Control Bellows Replacement 4/99
Applicability: All Allison Model 250-C18, C20, C28, C30, C20R, B15, B17, B17F series engines fitted with a main fuel control incorporating a beryllium copper Pc bellows.
Requirement: Replace the beryllium copper bellows assembly with an inconel 718 stainless steel bellows assembly as per AlliedSignal Aerospace Equipment Systems Service Bulletin GT-242 Revision 2.
Note: FAA Airworthiness Directive 98-24-28 refers.
Compliance: At the next main fuel control visit to an AlliedSignal Aerospace Equipment Systems authorised repair facility, regardless of the purpose of the visit, but no later than 31 October 1999.
This Airworthiness Directive becomes effective on 22 April 1999.
Background: This directive has been issued to require the replacement of beryllium copper fuel control Pc bellows. The requirement follows reports of leaking bellows resulting in uncommanded minimum fuel flow conditions, loss of fuel flow control and subsequent forced landings.
Overview
The Civil Aviation Regulations 1998, specifically Part 39 - 106, encompasses the Civil Aviation Safety Authority's schedule of airworthiness directives, including AD/AL 250/79 for Allison Turbine Engines - 250 Series. This legislative instrument was enacted to address the critical issue of fuel control bellows in Allison Model 250-C18, C20, C20R, C28, C30, B15, B17, and B17F series engines, which had been found to leak, leading to uncommanded minimum fuel flow conditions, loss of fuel flow control, and subsequent forced landings. The directive mandates the replacement of the beryllium copper Pc bellows with an inconel 718 stainless steel bellows assembly, as detailed in AlliedSignal Aerospace Equipment Systems Service Bulletin GT-242 Revision 2. The directive became effective on 22 April 1999 and required compliance by 31 October 1999, ensuring that all affected engines are serviced at an authorised repair facility regardless of the visit's original purpose. This measure was introduced by the Civil Aviation Safety Authority to enhance aviation safety by mitigating the risk associated with the identified component failure.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 106, applies to all Allison Model 250-C18, C20, C28, C30, C20R, B15, B17, and B17F series engines that are fitted with a main fuel control incorporating a beryllium copper Pc bellows. This regulation is enforced by the Civil Aviation Safety Authority (CASA) and has a national jurisdictional reach across Australia, ensuring the safety of all civil aviation operations within the Commonwealth. The directive mandates the replacement of the beryllium copper bellows assembly with an inconel 718 stainless steel bellows assembly in accordance with AlliedSignal Aerospace Equipment Systems Service Bulletin GT-242 Revision 2, with compliance required by 31 October 1999. This directive became effective on 22 April 1999 and stems from reports of leaking bellows that led to uncommanded minimum fuel flow conditions, loss of fuel flow control, and subsequent forced landings. The Federal Aviation Administration's Airworthiness Directive 98-24-28 is referenced in this context, illustrating a collaborative effort to enhance aviation safety standards.
Key Provisions
The Civil Aviation Regulations 1998, under Part 39, includes an Airworthiness Directive (AD) AD/AL 250/79, which mandates the replacement of beryllium copper bellows assemblies with inconel 718 stainless steel bellows assemblies for specific Allison Model 250 engines (Section 106). This directive applies to all Allison Model 250-C18, C20, C20R, C28, C30, B15, B17, and B17F series engines that are equipped with a main fuel control incorporating a beryllium copper Pc bellows. The replacement must be carried out in accordance with AlliedSignal Aerospace Equipment Systems Service Bulletin GT-242 Revision 2 (Section 4/99). The directive references the FAA Airworthiness Directive 98-24-28 and specifies that compliance is mandatory at the next main fuel control visit to an authorised repair facility, regardless of the visit's purpose, but no later than 31 October 1999. The directive became effective on 22 April 1999.
Entities governed by the AD must ensure that the specified replacement is completed by the stipulated date. This involves scheduling a visit to an authorised repair facility that is recognised by AlliedSignal Aerospace Equipment Systems. The directive emphasises that the replacement should occur at the next scheduled maintenance visit for the main fuel control, even if the visit was not originally intended for this purpose. Operators of the affected engines are required to ensure that their maintenance schedules are adjusted to comply with this directive. Additionally, the repair facility must be capable of performing the replacement as per the detailed instructions in the referenced service bulletin, which includes the precise technical specifications and procedures for the replacement.
Failure to comply with this Airworthiness Directive can lead to significant consequences. The primary concern is the potential for safety risks, as the directive is issued due to reports of leaking bellows that can result in uncommanded minimum fuel flow conditions, loss of fuel flow control, and forced landings. Civil Aviation Safety Authority (CASA) regulations do not specify maximum penalties for non-compliance in the context of ADs, but breaches can result in enforcement actions that may include fines, grounding of non-compliant aircraft, or other regulatory actions deemed necessary to ensure compliance and safety. The severity of the consequences reflects the critical nature of maintaining airworthiness standards to prevent hazardous conditions in aviation operations.