Just 2 weeks after Cirrus Design Corp. grounded its SR22/SR22T fleet due to an "engine issue," the FAA has published an immediate AD on Continental 360, 470, 520, and 550 series requiring an inspection of the crankshaft for possible improper installation of the counterweight retaining rings and requires corrective actions if improper installation is discovered. The FAA estimates a total of 1,632 U.S. registered aircraft will need inspection, requiring anywhere from 1 to 3 cylinders to be removed for said inspection. The cost associated with the new AD is estimated to be no more than $2,500, with some of the cost potentially being covered by warranty. The initial service bulletin published by Continental excluded aircraft with 200 hours of operation, however the FAA has not found sufficient information to allow said exclusion on the new AD. Affected engine serial numbers can be found here - Page 9