What was found
ENGINE QUIT IN-FLIGHT AND IT WAS DISCOVERED THE CRANKSHAFT HAD BROKEN IN TWO PLACES, JUST AFT OF THE FWD THRUST BEARING. RESEARCH OF LOGS SHOWS THAT THE AIRCRAFT WAS BELLIED 891 HOURS PRIOR TO THE CRANKSHAFT BREAKAGE, AT WHICH POINT THE BELLY WAS REPAIRED, A NEW PROPELLER INSTALLED, AND NO TEAR DOWN INSPECTION OF THE ENGINE PERFORMED. LUCKILY, NO ONE WAS INJURED DURING THE FORCED LANDING (IFR AT NIGHT), BUT THERE NEEDS TO BE A REGULATION REQUIRING A TEAR-DOWN INSPECTION OF AN ENGINE FOLLOWING A PROP STRIKE. TCM BULLETIN M84-16 RECOMMENDS TEAR DOWN IF THE PROP HAS TO BE REMOVED FOR REPAIR, BUT IS NOT REQUIRED. A REQUIREMENT FOR TEAR DOWN BASED ON THIS RECOMMENDATION WOULD ELIMINATE THIS 'GREY AREA'.