(An FAA maintenance inspector has annotated this next discrepancy, indicating the subject Cessna 421C engine is also a RAM conversion.)

The submitter states, “The operator complained of small oil leaks (observed) in cruise flight. (The engine was...) cleaned and then run to inspect for oil leaks. After extensive visual inspections and dye penetrant inspection, three cracks in the crankcase were discovered. Two cracks were noted extending from the top forward case-half bolt holes, and one crack was noted on the top left case under the magneto area.” (Crankcase P/N given as 639468. Part time since overhaul: 514.0 hours.)

Part Total Time: 3,459.0 hours.