N239CH
Registered owner: COLUMBIA HELICOPTERS INC, OR (owner ≠ operator)
Operators of this aircraft
Who operated this tail, and how firmly we know it.
| Operator | Role | Period | Basis |
|---|---|---|---|
| COLUMBIA HELICOPTERS, INC (CHIA) | Certificate holder | — | Matched by certificate designator |
| COLUMBIA HELICOPTERS, INC (CHIA) | Operator | 2008-08-22 – 2008-08-22 | Operator named in NTSB report |
| Columbia Helicopters Leasing | Operator | 2008-08-22 – 2008-08-22 | Operator named in NTSB report |
Accident & incident history
Maintenance disclosures
PILOT ACCOUNT: DURING FIRE FIGHTING MISSION, NR 2 ENGINE ROLLED BACK TO INTERMEDIATE SETTING (LESS THAT FLIGHT RPM WITH RRPM DECAY, ABOVE GROUND IDLE). THIS OCCURRED WHILE DROPPING WATER. EMERGENCY POWER WAS NECESSARY TO MAINTAIN RRPM. AFTER GAINING AIRSPEED AND RECOVERING RRPM, SIC PULLED OUT EACL AND EXECUTED DRILL NR 10. NO RESPONSE FROM BEEP TRIM SYSTEM. BUCKET REMAINED AS THE AIRCRAFT WAS CONFIGURED FOR S/E FLIGHT AND HAD THE PERFORMANCE TO RETAIN MISSION EQUIPMENT. NOTE, AT THE TIME OF THE ROLL BACK, 10,300LBS OF WATER WAS IN THE BUCKET. RECENT EVENT OCCURRED WITH A/C 239, WHICH ENDED UP HAVING ENGINE POWER RETURNING AND NEARLY CAUSING AN OVERSPEED. THE FLIGHT CREW RETURNED NR 2 ECL TO GND TO PREVENT FURTHER POWER UNCOMMANDED CHANGES. LANDED SINGLE ENGINE AT HEBER CITY AIRPORT WITHOUT FURTHER INCIDENT. MECHANIC ACCOUNT: T/S ENGINE CONTROL SYSTEMS, NO DEFECTS NOTED. SUSPECT OVERSPEED CONTROL BOX. REMOVED NR 2 AND SWAPPED IN NR 1 KNOWN GOOD OVERSPEED CONTROL BOX. INSTALLED SPARE OVERSPEED BOX INTO NR 1 POSITION. AIRCRAFT RETURNED TO SERVICE.
INTERIM SUPPLEMENTAL INFORMATION: THE OVERSPEED CONTROL BOX LISTED BELOW HAS BEEN RETURNED TO THE OEM (HONEYWELL) AND IS PRESENTLY UNDER EVALUATION BY THE OEM AND THE TC HOLDER. THIS SUPPLEMENTAL INFORMATION WILL BE UPDATED ONCE A ROOT CAUSE HAS BEEN ESTABLISHED.
NR 2 ENGINE ROLLBACK ON APPROACH TO WATER SOURCE. ENGINE SECURED PER EMERGENCY ABNORMAL CHECKLIST. COULD NOT FIND ANY DEPENDENCY DURING T/S. REMOVED AND REPLACED NR 2 CONTROL BOX AND ACTUATOR FOR T/S. ALL SUBSEQUENT CHECKS GOOD AND AIRCRAFT RETURNED TO SERVICE.
ON APPROACH TO DIP SITE NR 2 ENGINE FAILED TO RESPOND. NR 2 HUNG BACK AT AROUND 20% TQ, PILOTS WENT INTO EMERGENCY ENGINE TRIM & MANUALLY BEEPED ENGINE WITH NO RESPONSE. NR 2 ECL WAS BROUGHT BACK TO GROUND POSITION TO AVOID A POTENTIAL OVERSPEED CONDITION. EMERGENCY CHECK LIST DRILLS NR 10 AND NR 12 WERE COMPLETED. ON THE WAY BACK, PILOTS ATTEMPTED TO BRING NR 2 ECL BACK TO THE FLY POSITION, BUT ENGINE ACCELERATED AT A HIGHER RATE THAN NORMAL SO AGAIN SECURED NR 2 ECL AT GROUND POSITION FOR THE REMAINDER OF THE FLIGHT. ENGINE OPERATED ON TEST CELL FOR 4.7 HRS WITH NO DISCREPANCIES. FUEL CONTROL, BLEED BAND ACTUATOR, FUEL LIMIT VALVE, AND OVERSPEED CONTROLLER REMOVED TO SEPARATE WORK ORDERS FOR INSPECTION.
INFLIGHT, THE PILOT RECEIVED NO RESPONSE FROM THE PUMPS OR GATE VALVE ON THE SEI POWERPACK SYSTEM. THE 25 AMP CIRCUIT BREAKER WAS UNABLE TO BE RESET. PILOTS NOTICED AN ELECTRICAL SMOKE ODOR COMING FROM THE CABIN AREA. AIRCRAFT RETURNED TO BASE. CONFIRMED THE POWER PACK HAS EXPERIENCED AN ELECTRICAL FAILURE AND WAS COATED IN SOOT. INVESTIGATION DETERMINED AN EXCESSIVE BUILD UP OF SAND IN THE WATER BUCKET CAUSED BY A SHALLOW, SANDY, CREEK BED RESULTED IN AN EXCESSIVE CURRENT DEMAND ON THE POWER SUPPLY. DETERMINED THE ASSOCIATED CIRCUIT BREAKER WAS RESET MORE THAN ONCE.
WHILE PERFORMING AD 95-22-09, PARA A, 250 HR SPIRAL BEVEL INSPECTION OF THE AFT TRANSMISSION NR 12 BOLT BROKE DURING INITIAL TORQUE CHECK AT 275" LB.
DURING NORMAL ROTOR HEAD MAINTENANCE, THE TWO REPORTED TIE BARS WERE FOUND WITH NUMEROUS DEFECTS. THE DEFECTS CONSISTED OF SEVERAL CRACKED PLATES AT THE TIE BAR PINHOLE. THE TWO TIE BARS WERE SENT TO THE MANUFACTURER FOR EVALUATION AND AFTER DISASSEMBLY, ADDITIONAL DEFECTS WERE DISCOVERED. A ROTOR OVERSPEED MAY HAVE BEEN THE CAUSE OF THESE DEFECTS. HOWEVER, DURING THE LIFE OF THESE TWO TIE BARS, NO ROTOR OVERSPEEDS WERE REPORTED. THE MANUFACTURER CURRENTLY HAS THIS MATTER UNDER INVESTIGATION. (CHI2711)
PILOT ATTEMPTED TO APPLY SLIGHT AMOUNT OF AFT CYCLIC TO SLOW HELICOPTER AND EXTERNAL LOAD. THE CYCLIC WOULD NOT MOVE AFT OR FORWARD. NO SIGN OF ANYTHING BLOCKING THE CYCLIC MOTION, STILL HAD COLLECTIVE YAW AND ROLL CONTROLS, NO FORE AND AFT CONTROL. PILOT LOWERED COLLECTIVE FOR DESCENT TO A LANDING ON A ROAD IN EVENT CYCLIC CONTROL COULD NOT BE REGAINED. THE CYCLIC FREED AND A LANDING WAS MADE USING MINIMAL CONTROL INPUTS. POST-INSPECTION FOUND PITCH LOWER BOOST ACTUATOR OUTPUT TRUNNION WITH BINDING ROTATIONAL MOTION. (X)
THE HORIZONTAL HINGE PIN WAS REMOVED FOR A LEAKING SEAL. THE HINGE PIN WAS REMOVED AND THE LEADING SLEEVE REMAINED IN THE BEARING. THE SLEEVE WAS SPLIT AND THE BEARING WAS REMOVED WITH THE SLEEVE STILL INSTALLED. A NEW BEARING AND HORIZONTAL HINGE PIN WERE INSTALLED. THE ROTOR HEAD ASSY A5-1503 HAS ACCUMULATED 212 HOURS SINCE CENTER HUB REPLACEMENT. (X)
POST-FLIGHT CHECK REVEALED BLACK GREASE RUBBER AND WIRE FRAGMENTS COMING OUT OF THE GAP BETWEEN THE STATIONARY RING AND THE ROTATING RING. UNIT WAS REMOVED AND REPLACED. DISASSEMBLY OF SWASHPLATE SHOWED THE WIRE CAGE SEPARATOR HAD BROKEN UP. PAST FAILURES HAVE BEEN ATTRIBUTED TO FORMING CRACKS DURING MANUFACTURE OF THE CAGE. (X)
AT MORNING START-UP DURING THE AFCS CHECK, WHEN THE AFCS WAS TURNED ON, THE ROLL EXTENSIBLE LINK STARTED MOVING ERRATICALLY. THE PROBLEM WAS ISOLATED TO THE NR 1 AFCS, AT THIS TIME, THE ROLL LINK STARTED MOVING MORE ERRATICALLY UP AND DOWN. UPON FURTHER TROUBLESHOOTING, FOUND THE PROBLEM WAS IN THE 'AIR SENSING' SIDE OF THE NR 1 AFCS COMPUTER. THE COMPUTER WAS REPLACED AND OPS CHECKED GOOD.
PILOTS REPORTED INTERMITTENT NR 1 ENGINE TRANSMISSION HOT LIGHT. DURING TROUBLESHOOTING, FOUND M2001-517 TEMP SWITCH BROKE IN HALF AND WIRES PULLED OUT AT CANNON PLUG. REPLACED TEMP SWITCH AND CANNON PLUG. CHECKED GOOD. CAUSE UNKNOWN. SUBMITTER SUGGESTS POSSIBLE VIBRATION OR STRUCK DURING MAINTENANCE. (X)