Aircraft that have been grounded by an airworthiness directive (AD) affecting some Superior Air Parts replacement cylinder assemblies can get back in the air thanks to an alternative means of compliance approved by the FAA on May 19.
The alternative means of compliance is the result of collaboration between Superior Air Parts, AOPA, and the FAA. It extends the replacement interval from 12 years to 17 years’ time in service for affected cylinders. In keeping with the original AD, cylinders must be replaced at engine-hour TBO and compression checks are required every 50 hours on cylinder assemblies with more than 750 flight hours. In addition, affected engines will require a visual inspection of the cylinder exterior and borescope inspection of the cylinder interior for corrosion as well as a warm-engine soapy-water-leak test every 50 hours.
Affected owners must notify their local flight service district office of their intent to comply with the AD using the alternative means of compliance before taking action. The alternative means of compliance includes a sample notification letter to simplify the process for owners.
“Everyone concerned wanted to get grounded aircraft safely flying as quickly as possible, and we appreciate the hard work of Superior and the FAA to make this happen,” said Rob Hackman, AOPA vice president of regulatory affairs, who worked closely with both groups to develop an acceptable means of compliance.
The AD that grounded aircraft with certain Continental Motors engines took effect April 25. It was first issued in 2009 and reissued in March to address FAA concerns of “separation of the cylinder head, damage to the engine, and damage to the airplane.” Affected engines include Continental Motors IO-520, TSIO-520, and IO-550 engines, and any other engine, such as the 470 series, that has a supplemental type certificate for the same cylinder assemblies as the 520 and 550 series. The AD lists the Superior Air Parts part numbers that are affected.