Life limit on Superior Air Parts cylinders extended further

AOPA and Superior Air Parts jointly requested a global alternative method of compliance (AMOC) in March, seeking an update to an AMOC issued in 2020 that included a cylinder operating life limit of 21 years. AOPA and the company noted in the request that the ongoing inspections and other specifics of the 2020 AMOC had produced no evidence of component failure that originally prompted the airworthiness directive issued in 2014.

“AOPA and SAP strongly contend that the mitigations of visual inspections, compression checks, leak checks, and borescope inspections have, and will continue to, adequately address and mitigate the airworthiness concern .. the AD was issued to correct,” the joint request states. “Concerns of corrosion will continue to be mitigated through both a compression check and borescope inspection of each cylinder, performed per Continental Motors Service Bulletins, at 50-hour intervals or annually, whichever comes first.”

The FAA approved the update to the AMOC as requested weeks later, further easing the compliance burden for owners of aircraft powered by Continental IO-520, TSIO-520, and IO-550 engines, along with some in the 470 series operated under a supplemental type certificate with Superior Air Parts cylinder assemblies installed and more than 750 hours' time in service. The original AD mandated a 12-year life limit on the cylinders, and subsequent extensions granted additional time in service. The 2018 extension ended the effective grounding of some aircraft, a situation to which AOPA objected on behalf of members. AOPA and Superior Air Parts noted then that extending the cylinder life limits would save significant cost to owners, and that no known accidents or incidents resulting from cylinder head separation had occurred since the AD was issued in 2014. That remains true, as noted in recent correspondence to and from the FAA.

“AOPA appreciates the FAA considering the demonstrated evidence of safety and data in approving our request. This extension will reduce the risk and cost of prematurely replacing these cylinders, while also maintaining safety through continued inspections and checks,” said Christopher Cooper, AOPA senior director of regulatory affairs. “AOPA will continue to advocate for and support evidence-based decision making by the FAA for the continued operational safety of general aviation aircraft.”