Because of reports of cracks in 35 EQ3 cylinders from Teledyne Continental Motors (TCM), the FAA has issued an airworthiness directive (AD) that requires initial and repetitive inspections of TCM EQ3 cylinders installed on TCM O-470, IO-470, TSIO-470, IO-520, TSIO-520, IO-550, and IOF-550 series reciprocating engines. The AD, which goes into effect Oct. 7, also requires eventual removal of all EQ3 cylinders.
The cracks were reported on cylinders that had between 400 and 1,300 hours. TCM determined that its EQ3 configuration cylinder head casting tool used in the manufacturing process created an area of reduced wall thickness, which could lead to cracking between the cylinder’s upper spark plug bore and the fuel injector/primer nozzle bore. The affected cylinders were shipped between Nov. 1, 2007 and Jan. 30, 2009. The cylinders also were produced in August and September 2006.
Within 20 flight hours after Oct. 7, EQ3 cylinders with more than 400 hours total time must be visually inspected for cracks. Those with fewer than 400 hours must undergo a visual inspection before reaching that time limit. Repetitive visual inspections must be conducted every 50 hours of operation, and all cylinders with cracks must be replaced. The AD requires the cylinders to be removed from service before reaching 1,300 hours total time, regardless of whether cracking is evident.
TCM is offering warranty coverage. See the Web site for details.
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