As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LT MAG FAILED DURING CLIMB-OUT. RETURNED TO AIRPORT. DURING ROLL-OUT, RT MAG FAILED. INVESTIGATION REVEALED BOTH DISTRIBUTOR GEARS HAD BROKEN TEETH. MAG HAD BEEN OVERHAULED APPROXIMATELY 400 HOURS PRIOR, BUT GEARS DID NOT APPEAR TO BE NEW DUE TO DISCOLORATION OF PLASTIC. TOTAL TIME ON GEARS UNKNOWN. OUTSIDE AIR TEMP WAS MINUS 9 DEGREES BELOW ZERO. ENGINE HAD BEEN PREHEATED AND GROUND RUN PRIOR TO FLIGHT.