ENGINE FAILURE RESULTS IN A FORCED LNDG.

Narrative

AFTER HAVING BEEN IN SHOP FOR MAINT ITEMS INCLUDING OIL LEAK PROB. THIS ACFT ENG HAD ITS NORMAL 1400 HR TBO EXTENDED TO 1800 HR THRU APPROVED MAINT PROCS. THIS PARTICULAR ENG HAD A HISTORY OF OIL PROBS HAVING BEEN GNDED FOR AN OIL LEAK WITH A CYLINDER REPLACED LESS THAN A MONTH PRIOR. THE ENG HAD APPROX 100 HRS TBO OR APPROX 1700 HRS TOTAL TIME. OFF DPA AT XA30 CDT FOR SHAWANO; WI. DURING CRUISE AT 4500' 10 W OF WAUKESHA THE OIL PRESSURE BEGAN TO GO DOWN. I IDLED ENG; LANDED AT WAUKESHA CO ARPT; OIL FILLER CAP WAS LOOSE; ENG OIL LEVEL WAS AT 1 TO 1-1/2 QTS. I CALLED FBO TO FIND OUT WHAT CORRECTIVE ACTION THEY HAD TAKEN. THEY SAID NO PROB WAS FOUND-NO ACTION WAS TAKEN. I QUESTIONED THE MECHANIC AT WAUKESHA CO ARPT WHO SAID HE HAD SEEN THIS PROB SEVERAL TIMES BEFORE WITH THIS TYPE ENG. HE PUT A THICKER GASKET ON THE OIL CAP SAYING THIS SHOULD TAKE CARE OF THE PROB. HE HAND PROPPED THE ENG AND DETERMINED THE COMPRESSION WAS OKAY. THE LINEMAN FILLED THE ENG WITH OIL. RUNUP WAS MADE; FULL OIL PRESSURE OBSERVED. DEP FROM WAUKESHA AT XC30 CDT. 2 MINUTES INTO CLB; OIL PRESSURE WENT FROM FULL NORMAL TO ZERO. WITHIN SEVERAL SECONDS ENG BEGAN TO MAKE LOUD NOISES AS IF A ROD HAD BROKEN. ENG WAS SHUT DOWN. UNABLE TO MAKE ARPT; AN OFF FIELD LNDG WAS SUCCESSFULLY COMPLETED. IT WOULD SEEM THAT AN EXTENSION OF THE TBO ON THIS ENG SHOULD NOT BE A RECOMMENDED PROC. FURTHER THIS PLT HAD PUT HIS COMPLETE FAITH AND TRUST IN THE MECHANIC'S KNOWLEDGE OF THE MAINT PROCS FOR THIS SPECIFIC AIRPLANE AND ENG. DESPITE THE POSSIBLE CONSEQUENCES OF AN OFF FIELD LNDG; REALIZATION OF THE EMER AT HAND CAME IMMEDIATELY AND TRAINING ENABLED TOTAL CONCENTRATION WITH SOLE CONSIDERATION GIVEN TO THE SAFETY OF THE ACFT AND ITS OCCUPANTS.