Narrative:

As an employee of a repair station I was involved with the repair and overhaul of a continental W-670-23. The engine was returned to service and operated for 3 yrs accumulating approximately 150 hours. During a routine inspection it was discovered that the front crankcase had developed a crack. A subsequent teardown inspection of the engine by a third party has revealed that the following errors were made: 1) the parts manual calls out a part number 532455 front roller bearing and a part number 532454 rear roller bearing. According to the parts supplier at the time part number NUP213ECP and NUP212ECP were a suitable replacement. It has now been determined that these bearings are not an approved part. 2) during the overhaul, the crankcase was sent out to a certified repair station authority/authorized to perform crankcase repairs. This particular engine was not listed on their repair station certificate. We then inspected and returned the crankcase to service under our own repair station certificate. We now understand that we did not have the proper data to do this. 3) after the engine was assembled, it was returned to the owner to have a mechanic install the engine. Once the engine was installed into the airframe, it was to be run in accordance with the overhaul manual. The installing mechanic ultimately released the aircraft without a proper test run. Upon return to our facility for a warranty problem, the engine was repaired and test run per the overhaul manual. The following items are believed to have contributed to the errors: 1) lack of experience of the mechanic working on antique engines for which no factory support is available. 2) the availability of and willingness to sell unapproved parts by distributors of antique engine parts. 3) lack of training to our repair station on privileges and limitations. 4) failure to complete an overhaul without a test run (lack of proper equipment). The engine has been removed from service.

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Original NASA ASRS Text

Title: A REPAIR STATION TECHNICIAN RPTS THE REPAIR AND OVERHAUL OF AN ANTIQUE RADIAL ENG WITH UNAPPROVED FRONT AND REAR ROLLER BEARINGS.

Narrative: AS AN EMPLOYEE OF A REPAIR STATION I WAS INVOLVED WITH THE REPAIR AND OVERHAUL OF A CONTINENTAL W-670-23. THE ENG WAS RETURNED TO SVC AND OPERATED FOR 3 YRS ACCUMULATING APPROX 150 HRS. DURING A ROUTINE INSPECTION IT WAS DISCOVERED THAT THE FRONT CRANKCASE HAD DEVELOPED A CRACK. A SUBSEQUENT TEARDOWN INSPECTION OF THE ENG BY A THIRD PARTY HAS REVEALED THAT THE FOLLOWING ERRORS WERE MADE: 1) THE PARTS MANUAL CALLS OUT A PART NUMBER 532455 FRONT ROLLER BEARING AND A PART NUMBER 532454 REAR ROLLER BEARING. ACCORDING TO THE PARTS SUPPLIER AT THE TIME PART NUMBER NUP213ECP AND NUP212ECP WERE A SUITABLE REPLACEMENT. IT HAS NOW BEEN DETERMINED THAT THESE BEARINGS ARE NOT AN APPROVED PART. 2) DURING THE OVERHAUL, THE CRANKCASE WAS SENT OUT TO A CERTIFIED REPAIR STATION AUTH TO PERFORM CRANKCASE REPAIRS. THIS PARTICULAR ENG WAS NOT LISTED ON THEIR REPAIR STATION CERTIFICATE. WE THEN INSPECTED AND RETURNED THE CRANKCASE TO SVC UNDER OUR OWN REPAIR STATION CERTIFICATE. WE NOW UNDERSTAND THAT WE DID NOT HAVE THE PROPER DATA TO DO THIS. 3) AFTER THE ENG WAS ASSEMBLED, IT WAS RETURNED TO THE OWNER TO HAVE A MECH INSTALL THE ENG. ONCE THE ENG WAS INSTALLED INTO THE AIRFRAME, IT WAS TO BE RUN IN ACCORDANCE WITH THE OVERHAUL MANUAL. THE INSTALLING MECH ULTIMATELY RELEASED THE ACFT WITHOUT A PROPER TEST RUN. UPON RETURN TO OUR FACILITY FOR A WARRANTY PROB, THE ENG WAS REPAIRED AND TEST RUN PER THE OVERHAUL MANUAL. THE FOLLOWING ITEMS ARE BELIEVED TO HAVE CONTRIBUTED TO THE ERRORS: 1) LACK OF EXPERIENCE OF THE MECH WORKING ON ANTIQUE ENGS FOR WHICH NO FACTORY SUPPORT IS AVAILABLE. 2) THE AVAILABILITY OF AND WILLINGNESS TO SELL UNAPPROVED PARTS BY DISTRIBUTORS OF ANTIQUE ENG PARTS. 3) LACK OF TRAINING TO OUR REPAIR STATION ON PRIVILEGES AND LIMITATIONS. 4) FAILURE TO COMPLETE AN OVERHAUL WITHOUT A TEST RUN (LACK OF PROPER EQUIP). THE ENG HAS BEEN REMOVED FROM SVC.

Data retrieved from NASA's ASRS site as of July 2007 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.