In case some lurkers here are not on the AvWeb mailing list, it is very much worth checking out this story about the cause of a rash of recent catastrophic engine failures in Teledyne Continental engines:
The 11 engines that failed when their crankshafts snapped include the one in N5841, the SR20 that a CFI (I believe) from Windy City Fliers brought to a safe dead-stick landing in a field. Interestingly and hearteningly, the 10 other planes with failed engines also managed to land safely. Apparently Continental figured out that a batch of bad steel, used for casting a specific run of crankshafts, made their structure brittle and prone to sudden total failure. Now they’re ordering a massive testing of all the shafts made in the suspect period.
The good news is that they figured out the cause. The bad news is what this might mean for widespread grounding of planes, naturally including the Cirri, until each of the crankshafts is tested. But given that there was a real problem to be found, the good news of its discovery certainly outweighs the bad. Jim Fallows