Allison 250-C20B
Service difficulty reports · 1,981
Newest first. General aviation reporting is voluntary.
Query with SQL
duckdb -csv -c "SELECT sdr_id, difficulty_date, n_number, aircraft_make, aircraft_model, part_name, part_condition, jasc_code, discrepancy FROM 'https://openairdocs.org/data/latest/faa_service_difficulty_report.parquet' WHERE engine_model_key = '250C20B' ORDER BY difficulty_date DESC"
Prints the whole list as CSV. It reads the release’s Parquet files over HTTPS, so there’s nothing to download first. Install DuckDB to run it.
SELECT sdr_id, difficulty_date, n_number, aircraft_make, aircraft_model, part_name, part_condition, jasc_code, discrepancy FROM 'https://openairdocs.org/data/latest/faa_service_difficulty_report.parquet' WHERE engine_model_key = '250C20B' ORDER BY difficulty_date DESC
Run it at the DuckDB prompt, or in any tool that reads Parquet over HTTPS. More ways to query the release are on Use the data.
SDR CA960212034Bellows · frozen(CAN)LEFT CYCLIC INPUT RESTRICTED DUE TO BUILD UP OF ICE ON FORWARD BELLOWS ON THE HYDRAULIC PACK INPUT ROD.SDR CA960312006Scavenge Pump · failed(CAN) TIME THIS INSTALLATION - 1163.3 HOURS. NORMAL START UP AND TAKEOFF UNTIL TRANSLATION WHEN TORQUE AND OIL PRESSURE GAUGES STARTED TO FLUCTUATE. IMMEDIATE LANDING AND SHUT DOWN BY PILOT. ENGINE OIL LEVEL CHECKED, NO OIL FOUND IN ENGINE OIL RESERVOIR. NO EXSDR 96ZZZX1039Spline Shaft · cap detachedWHILE RETURNING TO BASE DURING FLIGHT, N2 RPM DROOPED. PILOT LANDED AIRCRAFT AND REPORTED MALFUNCTION TO THE MECHANIC. UPON INSPECTION OF GOVERNOR AND ATTACHING AIR LINES, THE DRIVE SPLINE RETAINING CAP WAS FOUND DETACHED AND SMALLER SHAFT FOUND PARTIALLY FASDR 96ZZZX3731Governor · shaft separatedENGINE RPM DROOPED. REMOVED N2 GOVERNOR AND FOUND DRIVE SPLINE, SPRING AND WASHERS HAD FALLEN OFF.SDR CA960123029Turbine · seized(CAN)DURING CRUISE FLIGHT, AIRCRAFT YAWED TO THE LEFT. PILOT LOWERED THE COLLECTIVE AND OBSERVED #2 ENGINE HAD FAILED. THROTTLE SECURED, AIRCRAFT RETURNED TO BASE. INVESTIGATION REVEALED N1 GEAR TRAIN UNAB LE TO ROTATE WITH STARTER. ENGINE DISASSEMBLED, TURBINSDR 96ZZZX432Valve · leakingANTI-ICE VALVE WAS LEAKING. FOUND THE PLUNGER WAS WORN ON ONE SIDE ALLOWING THE VALVE TO BE COCKED OFF ITS SEAT. REPLACED PART.SDR 96ZZZX630Outlet Strainer · missingDURING ROUTINE/RECOMMENDED 1,000-HOUR INSPECTION OF THE OUTLET STRAINER ASSEMBLY, THE SCREEN WAS NOT INSTALLED, RATHER AN INLET FITTING, PN 1740235, WAS INSTALLED. THIS UNIT IS APPROXIMATELY 980 HOURS TSN. SUBMITTER RECOMMENDS COMPLETE INSPECTION OF ASSY (FISDR HEEA966377Wheel · blade delamENGINE REMOVED DUE TO TURBINE OVERHAUL. UPON INSPECTION OF TURBINE PARTS NOTED THE FOLLOWING: SULFIDATION CAUSING DELAMINATION ON ALL 1ST STAGE WHEEL BLADES AND EROSION OF ALL LEADING EDGES. SCRAPPED 1ST STAGE WHEEL.SDR CA960126020Transmission · contaminated(CAN)METAL CONTAMINATION ON BOTH CHIP DETECTORS.SDR CA960126021Indicator · sticking(CAN)INDICATOR SLUGGISH RESPONSE AND NEEDLE STICKS.SDR HEEA966331Blade · delaminatedENGINE REMOVED DUE TO CYCLED OUT 2ND STAGE WHEEL. UPON INSPECTION OF TURBINE PARTS NOTED THE FOLLOWING: SULFIDATION OF 1ST STAGE WHEEL BLADES CAUSING DELAMINATION ON AFT SIDE OF LEADING EDGES. SCRAPPED 1ST STAGE WHEEL.SDR HEEA966332Blade · delaminatedENGINE REMOVED DUE TO CYCLED OUT WHEELS. UPON INSPECTION OF TURBINE PARTS NOTED THE FOLLOWING: SULFIDATION CAUSING SLIGHT DELAMINATION ON FORWARD SIDE OF ALL 1ST STAGE WHEEL BLADES AND EROSION ON LEADING EDGE. SCRAPPED 1ST STAGE WHEEL.SDR HEEA966334Blade · delaminatedENGINE REMOVED DUE TO CYCLED OUT WHEELS. UPON INSPECTION OF TURBINE PARTS NOTED THE FOLLOWING: SULFIDATION ON ALL 1ST STAGE WHEEL BLADES CAUSING SLIGHT DELAMINATION. SCRAPPED 1ST STAGE WHEEL.SDR HEEA966335Torquemeter · leakingENGINE REMOVED DUE TO TORQUE METER LEAKING.SDR 96ZZZX1167Combustion Liner · burnedWHILE REMOVING TURBINE, THE COMBUSTION LINER WAS FOUND BURNED, WARPED, AND CRACKED. PART REPLACED.SDR 96ZZZX2191Combustion Case · crackedWHILE IN CRUISE, PILOT NOTED ENGINE TOT WAS AT 800 DEGREES CELSIUS. MECHANIC INSPECTED ENGINE ASSY FOR EXTERNAL DAMAGE NOTING THE COMBUSTION CASE, PN 6870892-J, SN 27892, WAS CRACKED AT ARMPIT REINFORCEMENT. DURING TEAR-DOWN INSPECTION, THE FOLLOWING ITEMS WSDR 96ZZZX204Governor · defectiveGOVERNOR DROOPED TO 98 PERCENT N2 AND DID NOT RECOVER. N2 CONTINUED TO DROP WITHOUT RECOVERY. GOVERNOR ARM FELT STIFF. SENT IN FOR WARRANTY REPAIR. THE FOLLOWING ITEMS WERE REPLACED INSIDE GOVERNOR. PN 2520501, BEARING. PN 2523240, BEARING. PN 2525170, SDR 96ZZZX1386Turbine · over tempDURING NORMAL SHUT DOWN, PILOT ROLLED THROTTLE TO FLIGHT IDLE, NOTICED ENGINE OUT WARNING LIGHT, N1 DECAY, BUT TOT RISING. PILOT MOTORED ENGINE, BUT TEMPERATURE EXCEEDED 1,000 DEGREES CELSIUS. AIRCRAFT RIGGING CHECKED OK. REPLACED TURBINE AND G.P. FUEL CONTSDR 95ZZZX6620Nozzle · crackedREPLACED NR 1 NOZZLE FOR CRACKS AND BURNING. PART SENT IN ON ALLISON 250 REPORT NR 159680.SDR 95ZZZX6934Combustion Liner · crackedFOUND CRACKS IN THE 1ST SECTION CONE BEYOND LIMITS. RETURNED LINER FOR OVERHAUL ON ALLISON 250, REPORT 159678.SDR 95ZZZX6935Shield · warpedDURING REPLACEMENT OF NR 1 NOZZLE, THE NR 1 NOZZLE SHIELD WAS FOUND WARPED. SENT IN FOR REPAIR ON ALLISON 250 REPORT NR A159679.SDR 95ZZZX6622Turbine · nozzle crackedWHILE CHANGING NR 1 NOZZLE, IT WAS DISCOVERED THE NR 2 NOZZLE WAS CRACKED. UNIT WAS SENT IN FOR REPAIR.SDR HEEA956137Servomotor · sticksSTICKING ANTI-ICE ACTUATOR.SDR HEEA956080Blade · failedENGINE REMOVED DUE TO #1 BEARING OIL LEAK AND 3RD STAGE COMPRESSOR BLADE FAILURE. UPON INSPECTION OF COMPRESSOR PARTS NOTED THE FOLLOWING: ONE EACH BLADE BROKEN OFF ON 3RD STAGE WHEEL. SECONDARY DAMAGE -- 4TH STAGE WHEEL P/N 6876654, S/N ER58760SCRAPPED DUESDR HEEA956118Motor Assy · inopLINEAR ACTUATOR INOPERATIVE. REPLACED WITH SERVICEABLE ACTUATOR.SDR CA960126009Belt · worn(CAN)BELT WORN BEYOND LIMITS. 1000 HOUR NORMAL RETIREMENT LIFE.SDR CA960126010Governor · leaking(CAN)BEARING LEAKING BLUE GREASE AND FEELS ROUGH.SDR CA960126011Bearing · leaking(CAN)BEARING LEAKING GREASE AND FEELS ROUGH. FCU REPLACED.SDR 95ZZZX6472Combustion Liner · crackedCOMBUSTION LINER INSPECTION FOUND CRACK ON INSIDE OF DOUBLE LIP AT 8:00 POSITION ABOUT 2.5 INCHES LONG. LINER RETURNED FOR REPAIR ON ALLISON 250. REPORT NR R159723.SDR 95ZZZX68831st Stage Nozzle · crackedDURING PRE-FLIGHT OF AIRCRAFT, FOUND BURNED AND CRACKED AIRFOIL VANES AND CRACKS IN OUTER BAND. PART IS SCRAPPED.SDR 95ZZZX68874th Stg Nozzle · crackedDURING PRE-FLIGHT OF AIRCRAFT, FOUND 4TH STAGE NOZZLE WITH CRACKED DIAPHRAGM.SDR 95ZZZX6323Case Half · crackedINSPECTED CASE HALVES AT ANNUAL, FOUND PLASTIC CRACKED BEYOND LIMITS WITH SOME MATERIAL MISSING.SDR CA951122009Nozzle · below specfs(CAN)POWER CHECKS BELOW SPECS. TURBINE ASSEMBLY REPLACED. AIRCRAFT RETURNED TO SERVICE.SDR HEEA955927Bearing · failedENGINE REMOVED DUE TO #1 BEARING FAILURE. UPON INSPECTION OF COMPRESSOR PARTS NOTED THE FOLLOWING: #1 BEARING SEPARATOR BROKEN INTO MANY PIECES, INNER AND OUTER RACE SPALLED, BEARING BALLS SCORED AND FLATTENED. SECONDARY DAMAGE - MUTE RUB ON 1STSTAGE WHEELSDR 95ZZZX6197Nozzle · defectivePILOT COMPLAINED OF POWER/N2 FLUCTUATING WITH COLLECTIVE INPUT. SUBSEQUENT INSPECTION REVEALED THE FUEL NOZZLE WAS AT FAULT. REMOVED AND REPLACED NOZZLE AND PROBLEM WAS CURED. NOZZLE SENT IN FOR REWORK.SDR 95ZZZX6240Bleed Valve · sticksPILOT COMPLAINED THE POWER CHECK WAS INCONSISTENT. SUBSEQUENT INSPECTION REVEALED THE BLEED VALVE WAS STICKY. UNIT SENT IN FOR REPAIR ON ALLISON 250 REPORT NR A159719.SDR 95ZZZX6198Combustion Case · crackedINVESTIGATION FOR LOSS OF POWER AND HIGH T.O.T., FOUND COMBUSTION CASE CRACKED.SDR 95ZZZX6243Seal · leakingINSTALLED NEW SEAL AFTER INSPECTION OF UNIT. STARTED LEAKING OIL AFTER VERY LITTLE TIME IN SERVICE. SUBMITTER STATED BELL SEEMS TO HAVE CHANGED MANUFACTURERS. SEAL IS GARLOCK TYPE, BUT BLACK INSTEAD OF USUAL ORANGE COLOR. APPEARS TO BE OF DIFFERENT MATERIASDR 95ZZZX6204Bearing · making metalBEARING MAKING METAL. REPLACED WITH NEW UNIT(S), CORRECTED PROBLEM.SDR 95ZZZX5912Bearing · making metalINSPECTED AIRFRAME SCAVENGE OIL FILTER PER SUPERIOR TURBINE INFORMATION BULLETIN NR 95-IB001 (SB T95-SB001). FOUND 13 SILVER FLAKES IN FILTER BOWL. NO ABNORMAL INDICATIONS OR CHIP LIGHTS. REPLACED WTIH NEW SERVICEABLE BEARING. SUPERIOR TURBINE OFFERED EXCESDR HEEA955670Switch · malfunction#2 ENGINE DIFFERENTIAL PRESSURE SWITCH WOULD NOT FUNCTION CHECK AS PER BO-105 M & O CHAPTER 62 PAGE 43 PARA. 62-39 ITEM #2. REPLACED DIFFERENTIAL PRESSURE SWITCH.SDR 96ZZZX616Fuel Control · failureFAILURE OF DRIVE BEARINGS AND DAMAGE TO INTERNAL FLYWEIGHTS AND HOUSING CAUSED HIGH END TURBINE RUNAWAY RESULTING IN ENGINE OVERSPEED.SDR 95ZZZX5540Governor · failedWHILE IN CRUISE FLIGHT, THE PILOT NOTICED A DECREASE IN MAIN ROTOR RPM AND THE NOSE OF THE HELICOPTER NOTICEABLY YAWED. THE PILOT DECREASED COLLECTIVE PITCH, BUT THE ENGINE POWER AND ROTOR RPM CONTINUED TO DECREASE. THE ENGINE DID NOT FAIL COMPLETELY. DURINSDR 95ZZZX5541Fuel Control · faultyWHILE IN CRUISE FLIGHT, THE PILOT NOTICED A DECREASE IN MAIN ROTOR RPM AND THE NOSE OF THE HELICOPTER NOTICEABLY YAWED. THE PILOT DECREASED COLLECTIVE PITCH, BUT THE ENGINE POWER AND ROTOR RPM CONTINUED TO DECREASE. THE ENGINE DID NOT FAIL COMPLETELY. DURINSDR 95ZZZX5539Fuel Control · malfunctionFUEL CONTROL WILL NOT RESPOND PROPERLY TO ADJUSTMENTS FOR START TEMPS. START TEMPS GO EITHER HOT OR COLD IN AN ERRATIC MANNER. RETURNED CONTROL FOR BENCH CHECK.SDR 95ZZZX5213Bearing · making metalBEARING WAS PURCHASED AS PMA PART FROM SUPERIOR TURBINE. AN INFORMATION LETTER FROM SUPERIOR DATED MAY 1, 1995, RECOMMENDED INSPECTION OF BEARING AND FILTER FOR METAL FLAKES. THIRTEEN PIECES FOUND IN FILTER, ONE WAS 'TRIANGULAR 2 X 4MM', SINCE TWO SB HAVE BESDR HEEA955576Wheel · sulfidationENGINE REMOVED DUE TO LOW POWER. UPON INSPECTION OF TURBINE PARTS NOTED THE FOLLOWING: MILD SULFIDATION OUT OF OVERHAUL MANUAL LIMITS ON ALL 1ST STAGE TURBINE WHEEL BLADES. SCRAPPED 1ST STAGE WHEEL.SDR 95ZZZX4279Governor · erraticGOVERNOR IS ERRATIC WITH ANY POWER CHANGE. UNIT REMOVED AND SENT IN FOR REPAIR ON ALLISON 250 REPORT NR A151615.SDR CA960212027Nozzle · carbon buildup(CAN)DURING FLIGHT, AT ABOUT 150' AGL, THE ENGINE FLAMED OUT AND THEN RELIT, HOWEVER THE ENGINE RPM ONLY REACH 30 PERCENT NG. THE PILOT CARRIED OUT AN AUTOROTATION. THE AIRCRAFT WAS FITTED WITH FLOAT GEAR.DURING THE FLARE AND RUN-ON LANDING, THE TAIL SKID CONTSDR 95ZZZX4037Turbine · locked-upN2 LOCKED UP. UNIT SENT IN FOR SAME PROBLEM 356.7 HOURS AGO. REMOVED SN CAT 33968 AND SENT TO BE REPAIRED ON ALLISON REPORT NR A160209.
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