N508AM

Part: LIGHT — SMOKE (CABIN CENTER) · airframe 6,520 hrs · 17,266 cycles

CENTER CABIN LIGHT GAVE OFF A WISP OF SMOKE IN FLIGHT. PILOT CONTINUED WITH FLIGHT AND MEL ON GROUND AT BASE. I COULD NOT VERIFY PROBLEM AND CHECKED BY REMOVING ASSEMBLY. NO RESIDUAL SMELL EVER DETECTED. CHANGE ONE SUSPECT BULB SHOWING AGE. CLEANED ASSEMBLY AND TESTED 8 MINUTES ON GROUND. NO DEFECTS NOTED. SUSPECTED CONDENSATION OF SOME SORT COOKING OFF (MEDESOL) AS BULBS GET EXTREMELY HOT. CLEARED MEL 06 DEC 2022 AFTER SEVERAL ATTEMPTS TO DUPLICATE SMOKE.

Part: DECK PLATE — CHAFED (ENGINE BAY) · airframe 5,756 hrs · 15,664 cycles

DAMAGE WAS NOTED TO THE ENGINE DECK (PN: 350A21-1239.21) IN THE FORM OF CHAFES. THE DAMAGE AREAS WERE DISCOVERED TO BE OUTBOARD FROM THE SCUPPER DRAIN HOLE WITH THE LARGEST CHAFE MEASURING 0.40” X 0.30” AND REPORTED TO BE 0.108MM (0.004”) DEEP.

Part: DRAIN VALVE — LEAKING (ENGINE START) · airframe 5,196 hrs · 14,448 cycles

PILOT WROTE UP SMOKE AND FUMES IN COCKPIT. UPON TROUBLESHOOTING MAINTENANCE FOUND THAT THE START ELECTRO VALVE HAD FAILED CAUSING FUEL VAPOR AND MIST TO BE FORCED THROUGH THE P2 AIR LINE USED FOR CABIN HEAT. REPLACED START ELECTRO VALVE. OPS CHECK GOOD.

Part: WIRE — BROKEN (PRESSURE SWITCH) · airframe 5,124 hrs · 14,280 cycles

RETURNED TO BASE DUE TO A BURNING, CHEMICAL ODOR IN THE CABIN. THE MECHANIC PERFORMED A VISUAL INSPECTION, AND FOUND A BROKEN WIRE ON THE AC SYSTEM HI/LO PRESSURE SWITCH. CORRECTED THE DISCREPANCY AND HAD THE PILOT PERFORM A 30 MINUTE PENALTY RUN WITH NO DEFECTS NOTED. THE AIRCRAFT WAS RETURNED TO SERVICE AT THIS TIME.

Part: GEARBOX — DAMAGED (MAIN ROTOR) · airframe 2,790 hrs · 9,224 cycles

UPON REMOVING THE ENGINE TO MAIN GEARBOX SHAFT TO REPLACE THE MAIN GEARBOX INPUT SEAL. I FOUND THAT THE CASTLATED NUT THAT HOLDS THE ROTOR BRAKE DISK IN PLACE WAS LOOSE. REMOVED NUT, WASHER (SIGNS OF SPINNING IN PLACE) BRAKE DISK, LARGE FLAT WASHER UNDER DISK AND FOUND THAT THE LARGE FLAT WASHER HAS WORN A GROOVE INTO THE GEARBOX FLANGE. REMOVED FRICTION RING AND FOUND THAT IT WAS STEPPED AND THAT THE INNER BASE THAT GOES TOWARD THE GEARBOX HAD SIGNED OF WEAR.

Part: UNKNOWN — ODOR · airframe 2,412 hrs · 8,188 cycles

IN CRUISE FLIGHT TO PICK UP A PATIENT. ABOUT 5 MINUTES PRIOR TO OUR PRECAUTIONARY LANDING, THE CREW STATED THAT THEY WERE SMELLING SOMETHING THAT MIGHT BE ELEC BURNING. THE ODOR SEEMED TO FADE IN & OUT, WERE NOT SURE IF IT WAS COMING FROM THE ACFT. IT STARTED TO RETURN SLIGHTLY STRONGER & WE IDENTIFIED IT AS POSITIVELY COMING FROM THE HELICOPTER. AT THIS POINT WE DECIDED TO MAKE A PRECAUTIONARY LANDING AT THE AIRPORT. WHILE ON LONG FINAL, THE CREW STATED THAT THEY COULD SEE SMOKE IN THE CABIN. LANDED & SHUTDOWN, AT ONE POINT DURING THE INCIDENT, WE THOUGHT THAT PERHAPS THE AIR CONDITIONING WAS THE SOURCE, HOWEVER SHUTTING IT DOWN DID NOT CHANGE THE SITUATION, IN FACT THE SMELL BECAME STRONGER AFTER SHUTTING IT OFF. DID NOT SEE ANY UNUSUAL INDICATION ON THE ACFT GAUGES OR SEE ANY SMOKE COMING FROM BEHIND THE CONSOLE OR IN THE AVIONICS AREA. DID NOT DECLARE AN EMER WITH ANY AGENCY. MECHANICS LOOKED THE ACFT OVER FOR THE NEXT 3 HOURS. DURING THAT TIME WE ACCOMPLISHED TWO 10-15 MINUTE GND RUNS, WITH VARIOUS COMBINATIONS OF ELEC EQUIP TURNED ON & OFF, COULD NOT DUPLICATE THE ODOR OR FIND ANY INDICATION OF BURNING ON THE ACFT. THE MECHANICS CONSULTED WITH THE REGIONAL LEAD MECHANIC & DECIDED TO CLEAR THE WRITE UP WITH CANNOT DUPLICATE. CONSULTED WITH THE RAD & WE RETURNED THE BASE TO BACK IN SERVICE. FLEW FROM THE TAXIWAY LOCATION OVER TO THE NA30 RAMP WITH THE MECHANIC. FLEW BACK WITH NO FURTHER INCIDENT.

Part: BATTERY — DISCHARGED (AFT TAILBOOM) · airframe 1,707 hrs · 6,239 cycles

PILOT REPORTED THAT HE BEGAIN TO LOSE ELECTRICAL POWER TO INSTRUMENTS AND INSTRUMENT LIGHTS, PILOT PREFORMED A PRECAUTIONARY LANDING. BATTERY WAS FOUND TO ONLY HAVE 16 VOLTS.

Part: STRUCTURE — CRACKED (CARGO DOOR) · airframe 1,575 hrs · 5,818 cycles

CRACK IN LOWER EDGE OF RT CARGO DOOR. CRACK IS VERTICAL, 1.2" IN LENGTH. CRACK DOES NOT APPEAR TO BE PROPAGATING.

Part: TUBE — BLOCKED (BLEED VALVE) · airframe 921 hrs · 2,646 cycles

DURING CLIMB, NOTIFIED OF SOME SMOKE TO THE LT SIDE OF THE COCKPIT NEAR THE DEMISTING VENT. SMOKE SLIGHT & APPEARED TO BE CONTINUOUS. VERIFIED NO VISIBLE FIRE OR SPARKS, & ALL ENGINE PARAMETERS NORMAL. CONFIRMED THE HEATING & DEMISTING KNOBS WERE CLOSED. DIVERTED FOR A PRECAUTIONARY LANDING. LANDING UNEVENTFUL. INSPECTED DUCTING FOR LEAKS OR DAMAGE, NONE FOUND. INSPECTION FOUND SMOKE TO HAVE A BURNING OIL ODOR. INSPECTED ENGINE AREA & FOUND OIL VENTING FROM BLEED AIR VALVE. INSPECTED EXHAUST VENT TUBE. FOUND TUBE HAD A DIME SIZED PIECE OF COKING THAT HAD SEPARATED FROM TUBE INNER WALL & WEDGED OPENING CLOSED. REMOVED TUBING AND CLEANED OUT ALL COKING. REINSTALLED TUBE. PERFORMED COMPRESSOR WASH AND RINSE. PERFORMED OPS CHECK AND LEAK CHECK. RAN ACFT WITH HEATERS & DEFROSTERS ON FOR 20 MINS UNTILL NO SIGN OF SMOKE EMINATED FROM SYS. PERFORMED OPS CHECK FLIGHT WITH HEATERS & DEFROSTERS ON. NO SMOKE. RETURNED TO BASE.

Part: BATTERY — DISCHARGED (MASTER) · airframe 683 hrs

DURING A NIGHT FLIGHT, FLIGHT INSTRUMENTS BEGAN TO FLICKER AND DIM. NOTED THAT THE GEN SWITCH WAS IN AND THERE WERE NO CAUTION LIGHTS. A COUPLE OF MINUTES LATER THE ENTIRE PANEL WENT OUT, INCLUDING THE VEMD, BOTH GARMIN GPS/RADIS. THE GMX 200 REMAINED ON AND THE SCREEN WENT TO VERY BRIGHT. ABOUT 20 SECONDS FROM LANDING THE GEN LIGHT CAME ON. AFTER LANDING SHUTDOWN WAS ACCOMPLISHED USING THE EMG FUEL CUTOFF AS NO ELECTRICAL POWER WAS AVAILABLE TO DO OTHERWISE. AFTER TROUBLESHOOTING STARTER/GENERATOR AND DC POWER SYS FOUND THE STARTER/GENERATOR TO BE IN WORKING ORDER. THE BATTERY VOLTAGE VERY LOW AND WOULD NOT HOLD A CHARGE. AFTER REPLACING BATTERY, ALL SYS WORKED PROPERLY EXCEPT FOR THE GMX200 IT WOULD NOT POWER UP. MEL'D GMX200 WAITING FOR NEW ONE. INSPECTED EVERYTHING EVEN REMOTELY CONNECTED TO THE POWER SYSTEM AND COULD NOT FIND ANYTHING. NO BREAKERS WERE TRIPPED AND NOTHING SMELLED BURNED.

Part: WIRE — FAILED (CLOCK BACKLIGHT) · airframe 101 hrs

ELECTRICAL ODOR IN COCKPIT FOLLOWED BY A SMALL PUFF OF SMOKE FROM FWD CTR RT OF GLARESHIELD TOP. ALL ACFT SYS APPEARED NORMAL WITH NO WARNING/ CAUTION LIGHTS. ODOR AND SMOKE DIMINISHED WHEN OUTSIDE AIR VENT KNOB WAS PULLED. SUSPECT FAULTY CLOCK BACKLIGHTING WIRING.