For the fourth time this year, the FAA acted to require repairs on certain 540-series Lycoming engines. This time, the agency issued a final rule AD this week on Lycoming crankshaft retaining bolts. AD 2002-23-06, applicable to Lycoming AEIO-540, IO-540, LTIO-540, O-540, and TIO-540 engines with part number STD-2209 crankshaft retaining bolts installed, supersedes Emergency AD 2002-20-51 issued in early October. The new AD requires engines that had crankshaft retaining bolts replaced during field overhaul or maintenance between November 27, 1996, and the present, and engines repaired at Lycoming between November 27, 1996, and November 10, 1998, to replace the defective bolt with a new retaining bolt contained in Lycoming kit number 05K19987. Under the new AD, certain owners who replaced defective bolts under the previously issued AD may be required to remove and replace the bolts once again.
Aircraft that complied with previously issued AD 2002-20-51 by installing crankshaft retaining bolt part number STD-2209 that was NOT included in Lycoming kit number 05K19987 must replace the bolt—again. Owners affected by previously issued AD 2002-20-51 who were fortunate enough to replace the defective Lycoming bolt with a new bolt from Lycoming kit number 05K19987 or a PMAed Superior Airparts bolt are NOT required to replace the bolt. The new AD requires owners to note in the aircraft log that they've replaced their defective part number STD-2209 bolt with a bolt from Lycoming kit 05K19987. Lycoming reports that plenty of replacement bolt kits are available, and the company will extend parts and labor warranty coverage for the AD-required bolt replacement. For more information and related service information, see AOPA's issue brief.