TRANSNORTHERN LLC

ON 6/9/26 ABOUT 1:00PM AKST, THE SUPER DC3 TAIL NUMBER N28TN WAS RETURNING TO ANCHORAGE WHEN THE #2 ENGINE FAILED. UPON INSPECTION THE #9 CYLINDER CRACKED AROUND THE BASE, SEPARATED FROM THE ENGINE AND LODGED IN THE COWLING. THE FLIGHT CREW SHUT THE ENGINE DOWN AND LANDED SAFELY IN ANCHORAGE. THE FLIGHT CREW STATED THAT THE FIRE LIGHT FOR THE #2 ENGINE BRIEFLY ILLUMINATED, AND THEY WERE ABLE TO GO THROUGH THE CHECKLIST AND EXTINGUISH THE LIGHT. AFTER INSPECTING THE DAMAGE WE DECIDED TO REMOVE THE ENGINE FOR REPAIR.

TORQUE SENSOR BEARING FAILED (PN: 3103585AL-1, SN: TA43-0510123, TSN: 2,125.4). SPECTROMETRIC OIL ANALYSIS PROGRAM RESULT REPORT DISCOVERED M50 PLATELETS, SHINY, >100, UP TO 1.1MMX0.9MM. M50 IS A BEARING RACE MATERIAL AND THE QUANTITY OF PLATELETS FOUND IN THE FILTER ANALYSIS INDICATES A BEATING IS FAILING.

AIRCRAFT DEPARTED FROM PANC TO PADQ. RIGHT HAND ENGINE LOST POWER AFTER TAKE OFF. HAD TO DIVERT TO PAMR AND LAND GEAR UP.

CRACKED AILERON SPAR AT BOTTOM OF CENTER HINGE BRACKET. DISCREPANCY OCCURRED UNDER NORMAL WEAR AND UTILIZATION. RECOMMEND CLOSE EXAMINATION OF THIS AREA AND THE OTHER HINGE ATTACH FITTINGS.

DURING CLIMB OUT, PILOT IN RIGHT SEAT NOTICED AN UNUSUAL TICKING NOISE. DURING INVESTIGATION, DETERMINED THAT IS WAS CAUSED BY A BOLT IN THE NOSE CASE OF THE RIGHT ENGINE BACKING OUT AND CONTACTING THE AFT FLANGE OF THE PROPELLER. CREW SECURED THE ENGINE AND RETURNED TO THE DEPARTURE AIRPORT. MAINTENANCE DETERMINED THAT A TOTAL OF 3 OF THE 10 BOLTS THAT SECURE THE NOSE CASE TO THE ENGINE HAD SHEARED AND WERE LOOSE.

AIRCRAFT DEPARTED, AFTER CLIMBOUT, WHILE TRIMMING FOR CRUISE, THE ACFT DEVELOPED A VIBRATION. PILOT ELECTED TO DIVERT TO INVESTIGATE PROBLEM. UPON LANDING, PILOT DETERMINED THAT THE LT ELEVATOR TRIM TAB WAS LOOSE. SUBSEQUENT INVESTIGATION BY MAINTENANCE PERSONNEL DETERMINED THAT THE TRIM TAB CONTROL ROD HAD BROKEN. MAINTENANCE DETERMINED THAT AT SOMETIME DURING THE AIRCRAFT'S HISTORY SOMEONE HAD DRILLED OUT A TAPER PIN CONNECTING HOLE AND INSTALLED AN AN BOLT. THIS CAUSED THE PART TO FAIL. WE HAVE EXAMINED THE OTHER SIDE OF THIS ACFT AND THE TRIM ACTUATORS ON THE REST OF OUR FLEET AND FOUND NO OTHER INCIDENTS OF THIS TYPE OF IMPROPER REPAIR.

FLIGHT RETURNING TO BASE AFTER FREIGHT CHARTER FLIGHT. UPON APPROACH PILOT SELECTED GEAR DOWN BUT DID NOT RECEIVE A GREEN LIGHT INDICATION FOR THE NOSE GEAR. PILOT RECYCLED GEAR AND REQUESTED TO TERMINATE LANDING. PILOT MANUAL EXTENDED THE LANDING GEAR IAW AFM PROCEDURES. NO INDICATION OF HYDRAULIC OR ELECTRICAL FAILURE. RELEASING MANUAL GEAR RELEASE EXTENDED AND LOCKED NLG. PILOT LANDED AND TAXIED TO BASE WITHOUT ANY ADDITIONAL INDICATIONS OF PROBLEMS. AIRCRAFT HAS NOT BEEN RETURNED TO SERVICE BUT SUSPECT PART IS THE LANDING GEAR SERVO IN THE HYDRAULIC POWER PACK ASSEMBLY . MAINTENANCE BELIEVES THAT THE SERVO IS NOT CLOSING COMPLETELY AND THEREFORE DIDN'T DEVELOP ENOUGH INITIAL PRESSURE TO RELEASE THE MECHANICAL UP LATCH DURING THE INITIAL GEAR DOWN OPERATION. MAINTENANCE DETERMINED THAT THE VALVE ASSY GEAR WHICH IS PART OF THE POWER PACK MAY HAVE BEEN NOT FULLY CLOSING CAUSING A BYPASS CONDITION. THIS PREVENTED THE GEAR DOWN SYSTEM PRESSURE TO BE LESS THAN NORMAL.

WHILE PERFOMING AD 2012-18-01, FOUND A CRACK ON THE LT FWD ATTACH FITTING BRACKET - CRACK LENGTH .5"

EMERG LAND MADE WITH RT GEAR UNSAFE LIGHT. AFTER SHUT-DOWN, RT LANDING GEAR, IB ACTUATOR WAS FOUND BROKEN AT FWD MOUNT, HANGING DWN BELOW GEAR DOORS FROM AFT MOUNT. (NOTE: EACH LANDING GEAR HAS 2 ACTUATORS, OB ACTUATOR HAD NO DAMAGE). BROKEN ACTUATOR APPEARS TO BE ORIG ACTUATOR, NO RECORDS CAN BE FOUND INDICATING REPLACEMENT SINCE AC WAS NEW. ACTUATOR REPLACEMENT SINCE IS (ON CONDITION) WITH NO REQUIRED OH TIME. BROKEN ACTUATOR WAS REMOVED, REPLACED, SENT FOR ANALYSIS. MFG DETERMINED THAT CRACK AT FWD MTNG HOLE, WHICH LEAD TO FAILURE, ORIGINATED IN SMALL FLAW IN METAL. GRADUALLY GREW TO POINT OF FAILURE. STATED THAT THIS IS ISOLATED INCIDENT, AND FEEL THAT NO FURTHER ACTION IS REQUIRED. (K)

MRR-M05-01, NR 1 WINDSHIELD CRACKED IN FLIGHT JUST AS CREW STARTED DESCENT. CREW DEPRESSURIZED AC, DESCENDED TO AN APPROPRIATE ALTITUDE FOR NON-PRESSURIZED FLIGHT, AND DIVERTED TO AN AIRPORT WITH VMC CONDITIONS. CREW LANDED WITH NO FURTHER INCIDENT. OAT WAS APPROXIMATELY -40 AND WINDSHIELD HEAT WAS ON LOW. INNER GLASS PANE CRACKED, UNDER INVESTIGATION WITH THE OVERHAUL/REPAIR FACILITY. INNER PANE OF THE HEATED WINDSHIELD CRACKED EXTENSIVELY. REPLACED WINDSHIELD, OPS CHECK AND LEAK CHECK GOOD. (K)

NR 1 WINDSHIELD CRACKED AT DESCENT FROM CRUISE, CREW DEPRESSURIZED AIRCRAFT, DESCENDED TO PROPER ALTITUDE, AND DIVERTED TO LAND WITHOUT INCIDENT. OAT WAS -40C, WINDSHIELD HEAT WAS ON "LOW". MAINTENANCE FOUND INNER PANE EXTENSIVELY CRACKED.

MRR-M04-19, CREW NOTICED SMOKE IN COCKPIT AS THEY WERE CLIMBING THROUGH 12,000 FT, DESCENDED TO 10,000 FT, DEPRESSURIZED, TURNED OFF BLEEDS, AND CONTINUED TO STATION UNPRESSURIZED. SUSPECTED ACM FAILURE OR BLEED HEAT CNTRL VALVE FAILURE. RAN BOTH ENG FOR 20 MIN, NO SMOKE NOTICABLE IN CABIN. INSPECTED LT AND TR TEMP CNTRL VALVES, WITH NO DEFECTS NOTED. INSPECTED LT AND RT ACMS, WITH NO DEFECTS NOTED. SERVICED BOTH ACMS AND REMOVED, CLEANED, REINSTALLED WATER SOCKS. RAN ENG SECOND TIME WITH NO DEFECTS NOTED. COULD NOT DUPL ORIGINAL WRITE-UP. WATER SEPARATOR ICED UP, AND WHEN IT WARMED UP, STEAM CAME THROUGH, MIMICING SMOKE. (NM05200502386) (K)

MRR-M04-18, DURING FLIGHT THE LT FIRE EXTINGUISHER (E) LIGHT CAME ON BRIEFLY SEVERAL TIMES. THE CREW MONITORED THE LIGHT AND THE FLIGHT WAS CONTINUED TO THE DESTINATION WITH NO INCIDENT. FIRE EXTINGUISHER (E) LIGHT WAS FOUND ON, AND THE FIRE EXTINGUISHER BOTTLE WAS FOUND EMPTY DURING TROUBLESHOOTING BY MAINTENANCE. THE SQUIB HAD BEEN FIRED. REPLACED FIRE EXTINGUISHER BOTTLE AND SQUIB HAD BEEN FIRED. REPLACED FIRE EXTINGUISHER BOTTLE AND SQUIB. FIRE BOTTLE PN: 3030020, SN 05782B1 OH 7-14-04, INSTALLED 7-19-04. NO DEFECTS WERE NOTED DURING TROUBLESHOOTING OR PARTS CHANGES. PRESS TO TEST FUNCTION AND ALL OTHER FUNCTION CHECKS WERE GOOD. (K)

WHILE CHANGING A WING INSPECTION OF UNDER SURFACE OF WING ATTATCH REVEILED CORROSION REQUIREMENT REPLACEMENT OF ATTATCH ANGLE AND ASSOCIATED WING SKIN.