Narrative:

On dec/fri/06; while completing an inspection; the company discovered that the left engine had an incomplete data tag. Aircraft X is owned by the company and used for far 135 operations. Upon further logbook research; it was discovered the serial number in the logbook did not match the serial number on the engine. This could have been a typo because all other components were correct. We then discovered the engine had exceeded its 12 yr calendar overhaul period. Per air carrier service information letter; the io 470 engine shall be overhauled every 1500 hours or 12 yrs. Being a 135 operator averaging 250+ hours per year per aircraft the 12 yr limit has never been a factor and quite honestly was not considered. Upon discovery of this problem; the company immediately grounded the aircraft and conducted an audit of all its aircraft. It was discovered that another aircraft; another C310Q owned by the company had the same issue with its left engine. The reason this happened was because the company purchased a salvaged C310 to supply parts to its fleet of C310's. 1 engine from the salvaged C310 went on the aircraft and the other engine went on another aircraft. Although the engines had low time since their last overhaul they had sat inactive long enough to allow them to reach the calendar limit.

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Original NASA ASRS Text

Title: A C310 L ENG DATA PLATE DID NOT MATCH THE LOGBOOK. ENG HAD EXCEEDED OVERHAUL LIMIT.

Narrative: ON DEC/FRI/06; WHILE COMPLETING AN INSPECTION; THE COMPANY DISCOVERED THAT THE L ENG HAD AN INCOMPLETE DATA TAG. ACFT X IS OWNED BY THE COMPANY AND USED FOR FAR 135 OPS. UPON FURTHER LOGBOOK RESEARCH; IT WAS DISCOVERED THE SERIAL NUMBER IN THE LOGBOOK DID NOT MATCH THE SERIAL NUMBER ON THE ENG. THIS COULD HAVE BEEN A TYPO BECAUSE ALL OTHER COMPONENTS WERE CORRECT. WE THEN DISCOVERED THE ENG HAD EXCEEDED ITS 12 YR CALENDAR OVERHAUL PERIOD. PER ACR SVC INFO LETTER; THE IO 470 ENG SHALL BE OVERHAULED EVERY 1500 HRS OR 12 YRS. BEING A 135 OPERATOR AVERAGING 250+ HRS PER YEAR PER ACFT THE 12 YR LIMIT HAS NEVER BEEN A FACTOR AND QUITE HONESTLY WAS NOT CONSIDERED. UPON DISCOVERY OF THIS PROB; THE COMPANY IMMEDIATELY GNDED THE ACFT AND CONDUCTED AN AUDIT OF ALL ITS ACFT. IT WAS DISCOVERED THAT ANOTHER ACFT; ANOTHER C310Q OWNED BY THE COMPANY HAD THE SAME ISSUE WITH ITS L ENG. THE REASON THIS HAPPENED WAS BECAUSE THE COMPANY PURCHASED A SALVAGED C310 TO SUPPLY PARTS TO ITS FLEET OF C310'S. 1 ENG FROM THE SALVAGED C310 WENT ON THE ACFT AND THE OTHER ENG WENT ON ANOTHER ACFT. ALTHOUGH THE ENGS HAD LOW TIME SINCE THEIR LAST OVERHAUL THEY HAD SAT INACTIVE LONG ENOUGH TO ALLOW THEM TO REACH THE CALENDAR LIMIT.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.