It's not often the FAA is more liberal than a company Service Bulletin in its handling of a potential safety issue but that appears to be the case with a proposed AD affecting thousands of suspect crankshafts in Lycoming engines. Lycoming's Mandatory Service Bulletin requires crank replacement the next time the crankcase is split or at next overhaul, but in any case, no later than Feb. 21, 2009. The MSB also includes a 90-percent discount on parts costs (leaving a bill of a couple thousand dollars, plus labor). But an earlier service instruction says engines must be overhauled when they reach their TBO or after a maximum of 12 years from new or overhaul. The FAA says the 12-year time limit is reasonable for low-use engines and it won't insist that crankshaft replacement match Lycoming's MSB schedule. However, those who don't go along with Lycoming's timetable could end up paying far more for the crankshaft and related parts, something AOPA isn't happy about. AOPA says it's lobbying Lycoming to change its pricing policy to match the FAA's requirements so that everyone affected by the AD gets the same deal. Under Lycoming's current requirements, those who change their cranks by the 2009 deadline will get the necessary parts for $2,000. The normal price, which will apply after that date, is $16,000. AOPA spokesman Luis Guitierrez said that might force some owners to pay labor to have their engines torn down twice, once for the crank replacement and later for the scheduled overhaul. "That is ridiculous. Lycoming should not put this cost burden on aircraft owners," he said.