Narrative:

During autofeather test on first flight of the day, system functioned properly but not within parameters established by company. I called the local operations station and asked them to call maintenance control. After discussing the problem, maintenance control said it was simply a small variation in the way that particular aircraft autofeather tested and that the aircraft could be released for our flight. Upon arrival at our maintenance station, mechanic came onboard and after discussing problem he told me that that was not the problem he had been told of during the phone conversation. The problem was that there were 2 high pressure switches installed on the autofeather system rather than 1 high and 1 low pressure switch. The aircraft had been to 1 maintenance base on MM/dd/92 and the mistake in parts probably occurred at that time. The flight was not compromised because the autofeather did function properly. The flight was uneventful and the problem was corrected prior to next flight. Problem could have been avoided if I had spoken directly to a mechanic in order to discuss the problem. Also aircraft should have never been released from maintenance base because system would not test within parameters. Company should publish and discuss with pilots more defined parameters and stricter follow-up when human error in aircraft maintenance is observed.

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Original NASA ASRS Text

Title: AN SMT PLT NOTICED THAT HIS AUTOFEATHER SYS WAS NOT WORKING QUITE RIGHT. MAINT SAID THAT IT WAS ALL RIGHT, THEN AFTER 1 OR MORE FLT, MAINT FOUND THAT WRONG PART HAD BEEN INSTALLED AT THE MAINT BASE.

Narrative: DURING AUTOFEATHER TEST ON FIRST FLT OF THE DAY, SYS FUNCTIONED PROPERLY BUT NOT WITHIN PARAMETERS ESTABLISHED BY COMPANY. I CALLED THE LCL OPS STATION AND ASKED THEM TO CALL MAINT CTL. AFTER DISCUSSING THE PROBLEM, MAINT CTL SAID IT WAS SIMPLY A SMALL VARIATION IN THE WAY THAT PARTICULAR ACFT AUTOFEATHER TESTED AND THAT THE ACFT COULD BE RELEASED FOR OUR FLT. UPON ARR AT OUR MAINT STATION, MECH CAME ONBOARD AND AFTER DISCUSSING PROBLEM HE TOLD ME THAT THAT WAS NOT THE PROBLEM HE HAD BEEN TOLD OF DURING THE PHONE CONVERSATION. THE PROBLEM WAS THAT THERE WERE 2 HIGH PRESSURE SWITCHES INSTALLED ON THE AUTOFEATHER SYS RATHER THAN 1 HIGH AND 1 LOW PRESSURE SWITCH. THE ACFT HAD BEEN TO 1 MAINT BASE ON MM/DD/92 AND THE MISTAKE IN PARTS PROBABLY OCCURRED AT THAT TIME. THE FLT WAS NOT COMPROMISED BECAUSE THE AUTOFEATHER DID FUNCTION PROPERLY. THE FLT WAS UNEVENTFUL AND THE PROBLEM WAS CORRECTED PRIOR TO NEXT FLT. PROBLEM COULD HAVE BEEN AVOIDED IF I HAD SPOKEN DIRECTLY TO A MECH IN ORDER TO DISCUSS THE PROBLEM. ALSO ACFT SHOULD HAVE NEVER BEEN RELEASED FROM MAINT BASE BECAUSE SYS WOULD NOT TEST WITHIN PARAMETERS. COMPANY SHOULD PUBLISH AND DISCUSS WITH PLTS MORE DEFINED PARAMETERS AND STRICTER FOLLOW-UP WHEN HUMAN ERROR IN ACFT MAINT IS OBSERVED.

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.