Narrative:

On may/thu/04, I reinstalled a bendix D4LN-3000 magneto serial number X on mooney 20J serial number Y after repair by an outside vendor. The installation was performed per manufacturer's pubs and a ground operational/leak check was performed with satisfactory results and no leaks noted. The aircraft flew approximately 35-40 hours subsequent to this installation and lost power on climb out from ZZZ at approximately XA00 local time on may/sat/04. The pilot made a successful power-off landing back at ZZZ. There were no injuries or property damage incurred. I was not aware of the occurrence until today (jun/tue/04). 2 mechanics from the company I work for traveled to assess the problem. They found the magneto had become detached from its mounting studs. After the magneto was reinstalled, the engine operated normally. It appears that I had failed to fully tighten the magneto mounting nuts after timing the magneto to the engine. The aircraft was scheduled to fly the next day and I felt pressured to complete the job. It was late in the day. I was probably distraction by someone or the phone. I didn't have another mechanic inspect the work before returning the aircraft to service. Prevention: do not allow pressure to complete the work cause me to rush. Avoid distrs. If not possible, go back several steps of work performed prior to the distraction. Have another mechanic doublechk work whenever possible.

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Original NASA ASRS Text

Title: A MOONEY 20J LOST PWR ON CLBOUT DECLARED AN EMER AND DIVERTED DUE TO LOSS OF ENG PWR. CAUSED BY MAGNETO MOUNTING NUTS NOT SECURED.

Narrative: ON MAY/THU/04, I REINSTALLED A BENDIX D4LN-3000 MAGNETO SERIAL NUMBER X ON MOONEY 20J SERIAL NUMBER Y AFTER REPAIR BY AN OUTSIDE VENDOR. THE INSTALLATION WAS PERFORMED PER MANUFACTURER'S PUBS AND A GND OPERATIONAL/LEAK CHK WAS PERFORMED WITH SATISFACTORY RESULTS AND NO LEAKS NOTED. THE ACFT FLEW APPROX 35-40 HRS SUBSEQUENT TO THIS INSTALLATION AND LOST PWR ON CLBOUT FROM ZZZ AT APPROX XA00 LCL TIME ON MAY/SAT/04. THE PLT MADE A SUCCESSFUL PWR-OFF LNDG BACK AT ZZZ. THERE WERE NO INJURIES OR PROPERTY DAMAGE INCURRED. I WAS NOT AWARE OF THE OCCURRENCE UNTIL TODAY (JUN/TUE/04). 2 MECHS FROM THE COMPANY I WORK FOR TRAVELED TO ASSESS THE PROB. THEY FOUND THE MAGNETO HAD BECOME DETACHED FROM ITS MOUNTING STUDS. AFTER THE MAGNETO WAS REINSTALLED, THE ENG OPERATED NORMALLY. IT APPEARS THAT I HAD FAILED TO FULLY TIGHTEN THE MAGNETO MOUNTING NUTS AFTER TIMING THE MAGNETO TO THE ENG. THE ACFT WAS SCHEDULED TO FLY THE NEXT DAY AND I FELT PRESSURED TO COMPLETE THE JOB. IT WAS LATE IN THE DAY. I WAS PROBABLY DISTR BY SOMEONE OR THE PHONE. I DIDN'T HAVE ANOTHER MECH INSPECT THE WORK BEFORE RETURNING THE ACFT TO SVC. PREVENTION: DO NOT ALLOW PRESSURE TO COMPLETE THE WORK CAUSE ME TO RUSH. AVOID DISTRS. IF NOT POSSIBLE, GO BACK SEVERAL STEPS OF WORK PERFORMED PRIOR TO THE DISTR. HAVE ANOTHER MECH DOUBLECHK WORK WHENEVER POSSIBLE.

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.