MERCY HEALTH - LIFE FLIGHT NETWORK LLC

ON DEPARTURE FROM (KGWB), HOSPITAL THE PILOT SIDE SEARCH LIGHT BEGAN PANNING TO THE RIGHT IN A 360-DEGREE ROTATION THAT COULD NOT BE STOPPED O, CONTROL BY THE PILOT. IMMEDIATELY TURNED THE SEARCH TIGHT OFF AND ATTEMPTED TO SLOW THE SEARCH LIGHT TO RESET AND TRY AGAIN. I WAS UNABLE TO LOCATE THE PILOT SIDE SEARCH LIGHT OR VERIFY THAT II HAD TURNED ON. ASSUMING THE BULB MAY HAVE BURNED OUT OR THE LIGHT WAS STUD< IN A RANDOM DIRECTION. I SWITCHED TO THE CO-PILOT SEARCH LIGHT AND BEGAN TO MOVE IT INTO VIEW WHEN IT ALSO BEGAN AN UNCONTROLLED RIGHT 360 ?? DEGREE TUM. IT WAS AT THIS POINT BOTH SEARCH LIGHTS WERE DETERMINED TO BE UNRELIABLE AND UNSAFE TO CONTINUE THE NIGHT. CALLED DISPATCH AND ADVISED WE WERE ABORTING THE FLIGHT LO RETURN TO KGWB FOR MAINTENACE. ON CALL MECHANIC AND TIER 1 WHERE NOTIFIED OF THE SERVICE INTERRUPTION AND A WRITE UP WAS ENTERED INTO THE (CAN) MAINTENANCE LOGBOOK. TROUBLESHOT SEARCHLIGHT SYSTEM FOR UN-COMMANDED ROTATION OF BOTH SEARCH LIGHTS IN FLIGHT. UPON FURTHER TROUBLESHOOTING, FOUND RELAYS ON SEARCHLIGHT SELECTOR SWITCH TO BE INOP. REPLACED BOTH RELAYS ON SELECTOR SWITCH AND REPLACED BOTH 4-WAY POSITION SWITCHES. OPS CHECK GOOD.

CHIPS 2 ILLUMINATED AFTER GEAR EXTENSION AND LANDING CHALLENGE AND RESPONSE CALL OUTS. JUST PASSING THROUGH 2000' MSL AFTER CALL OUTS WERE COMPLETE THE CHIPS 2 LIGHT ILLUMINATED. THE PIC ABORTED THE LANDING SEQUENCE AND DIVERTED TO SOUTHBEND INTERNATIONAL AIRPORT. 199SM LANDED WITH NO FURTHER ISSUE. DISPATCH WAS NOTIFIED AND INITIALED THE PAIP. THE MATERIAL ON YOUR CHIP PLUGS CONSISTS OF 800CV40 WHICH IS HIGH SPEED BEARING MATERIAL WITH SOME 40NC07 WHICH IS MATERIAL FROM THE SEPARATOR CAGES OF THE BEARING. GIVEN THAT THE MATERIAL WAS LOCATED ON MOS. GENERAL ELECTRIC, AND OIL RESERVE?? CHIP PLUGS AND NOT ON THE M03 ELECTRIC OR M01 MECHANICAL PLUGS THE MATERIAL MOST LIKELY ORIGINATED IN THE M04 OR MOS. OIL IS SUPPLIED FROM THE PUMP THROUGH THE LINKING TUBE LO MOS WHICH IS LUBRICATE ALONG WITH SENDING OIL LO M04 TO LUBRICATE ITS BEARINGS AFTER WHICH IT DRAINS. REMOVE AND REPLACE BOTH MODULES 04 AND 05 AS DIRECTED. THIS MAINTENANCE WAS COMPLETED 1/30/2024. POST MAINTENANCE CHECKS SATISFACTORY. N199SM HAS BEEN RETURNED TO SERVICE.