N537AL

Part: FLANGE — CRACKED (COMPRESSOR) · airframe 9,178 hrs

FOUND CRACKING OF FWD FLANGE BEYOND REPAIRABLE LIMITS.

Part: WINDOW — SEPARATED (PAX CABIN)

ON APPROACH TO LANDING, RT PASSENGER SLIDING WINDOW SEPARATED FROM THE AIRCRAFT. SECOND OCCURRENCE WITH SAME AC WITHIN A WEEK. REPLACED DOOR WITH SERVICEABLE DOOR AND WINDOW. (K)

Part: SPRING — FAILED (FRAHM)

AIRCRAFT DEVELOPED A VERTICAL VIBRATION IN FLIGHT. NOTIFIED MAINTENANCE. FRAHM DAMPER SPRING HAD FAILED. REMOVED AND INSTALLED FOUR NEW FRAHM DAMPER SPRINGS IAW MM. (K)

Part: SHOULDER BELT — ODOR (PAX CABIN)

AFTER DEPARTING LFT WITH MMS DIRECT TO SM58 PASSENGER IN BACK RT SEAT FORWARD FACING COMPLAINED OF (STRONG FUEL ODOR) TO THE POINT OF ASKING FOR AIR SICK BAG. DIVERTED AIRCRAFT FOR MAINTENANCE. MAINTENANCE INSPECTED ENGINE COMPARTMENT AT 100 PERCENT, NO LEAKS NOTED, REMOVED HAT RACK BIN, FUEL VALVE ACCESS PANEL, ENGINE MOUNT ACCESS PANELS AND ROLL OVER PANELS, NO LEAKS NOTED. REPLACED RT AFT PASSENGER SHOULDER HARNESS DUE TO A SLIGHT SMELL OF FUEL ODOR. REINSTALLED SAME AS REMOVED PANELS AND RELEASED THE AIRCRAFT TO SERVICE.

Part: ODOR — DETECTED (CABIN)

IN FLIGHT, DURING FLIGHT OUT TO EI 296 A PAX COMPLAINED OF FUEL ODOR IN THE CABIN. INSPECTED ENGINE AT 100 PERCENT NR, FLEW AIRCRAFT NOTED NO PRESENCE OF FUEL ODOR. INSPECTED PAX CABIN AREA, NO FUEL LEAKS AT BACK WALL, FLOOR AREA, OR UNDER AFT FACING SEATS. INSPECTED OVERHEAD BAGGAGE COMPARTMENT, FOUND NO EVIDENCE OF FUEL LEAKS, CLOSED PANELS AND BACK SEATS, RELEASED AIRCRAFT TO SERVICE. ALGA (M)

Part: HMU — UNSERVICEABLE (FUEL SYSTEM)

FUEL FUMES WERE NOTED IN THE AFT RT PORTION OF THE PASSENGER COMPARTMENT. NOTED TO BE STRONG, SO DIVERTED TO HAVE IT CHECKED. MAINTENANCE REMOVED HAD BIN AND FUEL VALVE ACCESS PANEL. WITH BATTERY POWER ON, BOOST PUMPS RUNNING AND FUEL VALVE OPEN NOTED HEAVY FUEL DRIP ALMOST STREAMING FOR HMU CASE DRAIN. ENGINE PAN ACCUMULATING FUEL AND SEEPAGE CAUSING VAPORS IN HAT BIN AREA. REMOVED UNSERVICEABLE HMU, PART ON ORDER.

Part: GEAR — SPALLED (M/R GEARBOX) · airframe 3,510 hrs

GEAR HAS HEAVY SPALLING. REMOVED AND REPLACED W/SERVICEABLE PART.

Part: GEAR — SPALLED (M/R GEARBOX) · airframe 3,510 hrs

GEAR HAS HEAVY SPALLING. REMOVED AND REPLACED W/SERVICEABLE PART.

Part: INDICATOR — MALFUNCTIONED (MGT)

IN CRUISE FLIGHT, EXCEDENCE ON MGT WITH CHECK INSTRUMENT LIGHT DURING CRUISE WITH INSTRUMENT INDICATOR IN THE GREEN (704 TO 714). THE MECHANIC CHECKED COMPUTER FOR EXCEDENCE, HAD NO EXCEDENCE OR FAULTS RECORDED, REPLACED INDICATOR MGT.

Part: CAP — CORRODED (SWASHPLATE)

DURING DISASSEMBLY FOR 2500 HOUR OVERHAUL. EXCESSIVE CORROSION ON LOWER FLANGE MATING SURFACE OF SWASHPLATE.

Part: GEAR — DAMAGED (M/R GEARBOX)

UPON INSPECTION OF PARTS, FOUND ROUGH GEAR TEETH EDGES AT RADIUS, CAUSING DMAGE TO MATING GEAR TEETH. THIS IS DUE TO IMPROPER MACHING AT RADIUS.

Part: PINION GEAR — SPALLED (M/R GEARBOX)

UPON INSPECTION OF PART. SPALLING AND GALLING GEAR TEETH DUE TO ROUGH EDGES ON T/M GEAR TEETH. (PN 6893673 SN NN144757) TT 1878.2.

Part: BELLCRANK — DAMAGED (TAIL ROTOR)

DURING SERVICE CHECK, NAS BOLT BORE ELONGATED ON SINGLE EAR OF BELLCRANK. MODIFY WITH STEEL TOP-HAT BUSHING.

Part: DISC PACK — CRACKED (TAIL ROTOR)

DAILY INSPECTION, COUPLING IS CRACKED, PROBABLE CAUSE IS EXCESSIVE RIGIDITY IN THE BEARING MOUNT SYSTEM. ALLOW TAILROTOR DRIVESHAFT TO FLOAT SO DISC PACKS DO NOT FLEX AS MUCH OR AS OFTEN. (M)

Part: PINION GEAR — FAILED (GEARBOX)

DISASSEMBLED GEARBOX DUE TO METAL IN OIL. CLEANED AND INSPECTED, FOUND EXCESSIVE GALLING ON PINION GEAR AND T/M GEAR TEETH. PINION GEAR HAD EXCESSIVE GALLING ON GEAR TEETH DUE TO IMPROPER MESHING OF T/R AND PINION GEAR. SECONDARY DAMAGE: T/M GEAR P/N 6893673 S/N NN 145216. TT: 866.7 HOURS. SPALLING GALLING GEAR TEETH. (X)

Part: DISC PACK — CRACKED (T/R DRIVE)

DURING 25-HOUR AD INSPECTION, NR 3 DISC PACK CRACKED AT FORWARD DISC. IT IS CRACKED IN ONLY ONE LOCATION.

Part: BOLT — STRETCHED (BLEED VALVE)

UPON DISASSEMBLY OF ENGINE FOR METAL, CHECKED BOLT TIGHTNESS BY MOVING COVER AND BODY ASSY. ACTUAL TORQUE ON BOLTS WAS ONLY 15 INCHES/POUNDS. THREE EACH BLEED VALVE COVER BOLTS WERE NOT TORQUED TO SPECS FROM FACTORY OR BOLTS ARE STRETCHING AFTER ASSEMBLY AND TORQUING.

Part: BEARING — GALLED (GEARBOX)

UPON INSPECTION OF BEARING (AFT) PTO GEAR FOUND WITH EXCESSIVE GALLING ON ONE BALL BEARING. SUBMITTER STATED POSSIBLE CAUSE FOR BEARING GALLING UNKNOWN.

Part: LINE — CLOGGED (GEARBOX)

UPON DISASSEMBLY OF GEARBOX, FOUND EXCESSIVE AMOUNTS OF SPLIT LINE SEALANT ON SPLIT LINE. NOTE: BEFORE DISASSEMBLY, FOUND ALOT OF SEALANT ALONG SPLIT LINE, OUTSIDE OF GEARBOX. UPON INSPECTION OF GEARBOX PARTS, FOUND SCAVENGE OIL TRANSFER TUBE NR 23004230 BLOCKED WITH SPLIT LINE SEALANT. SUBMITTER SUGGESTED POSSIBLE CAUSE AS EXCESSIVE AMOUNT OF SEALANT ON SPLIT LINE CAUSING SEALANT TO BEAD UP ALONG SPLIT LINE. THE BEAD OF SEALANT BROKE OFF AND BLOCKED OIL PASSAGE.

Part: GEAR — GALLED (GEARBOX)

ENGINE WAS REMOVED FOR METAL CHIPS ON UPPER AND LOWER CHIP PLUGS. UPON INSPECTION OF GEARBOX PARTS, FOUND PINION GEAR GALLING AND TORQUE METER GEAR SPALLING. NOTE: METAL CONTAMINATION CAUSED DAMAGE TO OTHER PARTS IN GEARBOX. SUBMITTER SUGGESTED IMPROPER MESHING BETWEEN TORQUE METER GEAR AND PINION GEAR WERE THE CAUSE FOR GALLING AND SPALLING OF GEARS.

Part: JOURNAL — MAKING METAL (GEARBOX)

UPON DISASSEMBLY OF GEARBOX, TORQUE METER SUPPORT JOURNAL WAS FOUND TO HAVE MAGNESIUM SLIVERS IN JOURNAL BORE. UPON FINDING MAGNESIUM SLIVERS IN TORQUE METER JOURNAL BORE, MEASURED JOURNAL AND FOUND IT TO BE OVER MFG SPECS 2.485 INCHES (MFG MAX LIMIT 2.480 INCHES). ALLISON INSTALLED THE OVERSIZE JOURNAL BY HAMMERING IN COVER CAUSING SLIVERS. THESE SLIVERS COULD ALSO HAVE CAUSED DAMAGE TO THE OTHER GEARBOX PARTS.

Part: SUPPORT — CRACKED (HORIZ STABILIZER)

DURING DAILY INSPECTION, FOUND SLAT SUPPORT P/N 206-023-119-110 (LT SIDE, 2ND FROM INBD) CRACKED. REMOVED AND REPLACED CRACKED SUPPORT.

Part: BOLT — LOOSE (VERTICAL FIN)

ON PHASE INSPECTION FOUND 3 OF THE 4 VERTICAL FIN MOUNTING BOLTS LOST TORQUE.

Part: BOLT — LOOSE (VERTICAL FIN)

ON PHASE INSPECTION FOUND 3 OF THE 4 VERTICAL FIN MOUNTING BOLTS LOST TORQUE.