The FAA has issued an Airworthiness Directive AD on a certain make of connecting rod found in about 2,800 Lycoming 360- and 540-series engines in service in the U.S. The AD covers engines that have had certain ECi connecting rods installed as part of a repair or overhaul. The FAA determined that the connecting rods covered by the AD have deficiencies in the journal bores that can cause fatigue and/or bearing failure, which can result in “uncommanded shutdown” of the engine. Offending rods that have seen more than 1,500 hours of service have to be replaced within 50 hours and the others must be replaced before reaching 1,500 hours. The engines have been installed in dozens of certified and experimental aircraft. The repairs, according to the FAA’s math, will cost about $700 per engine (we think it could be a lot more) and ECi has said it might give credit for returned connecting rods. Another AD affecting crankshafts in 1,128 engines in the same families takes effect on Oct. 21. The repair cost on those engines is estimated at more than $16,000 but Lycoming has said it will supply the parts for free.