Continental engine cylinders installed in some Model 470, 520 and 550 engines shipped since November 2007 are the subject of a voluntary recall issued on Feb. 12. The company expects to replace some 9,600 cylinders subject to cracking between the upper sparkplug bore and the fuel injector/primer nozzle bore.
Cracked cylinders that have been returned to Continental have come from “high use fleet operations with occurrence times ranging from approximately 430 to 1,300 total hours,” the Mandatory Service Bulletin said. The company said that “new cylinders will be provided at no cost to the affected customers.”
Cracks have been found in 36 EQ3 cylinder heads, so far, the MSB said, explaining identification and replacement procedures to owners. Aircraft types affected include Bellanca Super Vikings, Beechcraft Debonairs, Bonanzas and Barons, Commanders, Meyers’s, Navions, and Cessnas ranging from 180s to 414s.
Continental traced the problem to a specific tool used for EQ3 production. Castings from that tool may be subject to cracking in “an area of reduced thickness” which “may result in a crack after prolonged operation.” New engines and those fitted with EQ3 replacement cylinder heads during overhaul or rebuilding are affected.
Continental said that information is available by calling 888-200-7565 or 251-436-8665, and at www.tcmlink.com/cylinders on the World Wide Web. The latter has inks to the Service Bulletin, the company president’s letter, and answers to questions.