A new engine is only as good as the cylinders the shop or owner picks and cylinders have, episodically, proved problematic. As we go to press in early September, this is indeed the case with an extensive manufacturing run of Engine Components International cylinders that the FAA proposes to remove from service via a massive AD. At issue are about 30,000 ECI cylinders for Continental O-520- and O-550-series engines manufactured between 2002 and 2012. According to the FAA’s proposed rulemaking notice for the AD, more than 30 of these cylinders have suffered head-to-barrel separations due to two unique types of cracking. Although the FAA can’t explain the reason for these failures, it wants the affected cylinders removed from service via a complex, hour-based metric that it estimates would cost owners as much as $82.6 million, making the proposed AD one of the largest on record.
Not surprisingly, ECI is opposing the AD as being far too broad and unsupported by accurate data. It says the FAA has overestimated the number of true head/barrel separations and it believes the ones that have occurred were due to severe overheating caused by pilots mismanaging leaning. In response to the FAA’s shotgun approach, ECI would like to stick with a 2008 bulletin it issued against a smaller population of cylinders requiring inspection at 50-hour intervals and removal at TBO.