# Service difficulty reports: Allison 250-C20B

A list on [Allison 250-C20B](https://openairdocs.org/engine/allison-250-c20b.md).

Newest first. General aviation reporting is voluntary.

Page 1 of 40 · 1,981 reports

- [SDR 2026FA0000798](https://openairdocs.org/sdr/2026FA0000798.md): Lock Nut · failed · Sep 30, 2026 · N735CB · Engine (Turbine/Turboprop)
  > MS21043 NUTS ARE UTILIZED TO SECURE TURBINE, COMPRESSOR, FUEL CONTROL, GOVERNOR, AND HAVE BEEN FOUND NUMEROUS TIMES TO HAVE NOT MAINTAINED THE MANUAL SPECIFIED TORQUE AND HAVE BACKED OFF. NUMEROUS TIMES NUTS HAVE ARRIVED WITHOUT ANY DRAG TORQUE. THE LOCKING FE
- [SDR 2024FA0000959](https://openairdocs.org/sdr/2024FA0000959.md): Engine · making metal · Dec 12, 2024 · N454JH · Hughes 369E · Engine (Turbine/Turboprop)
  > PILOT EXPERIENCED AN ENGINE CHIP LIGHT DURING LANDING. ENGINE REMOVED FROM AIRCRAFT FOR FURTHER INVESTIGATION.
- [SDR 2024FA0000958](https://openairdocs.org/sdr/2024FA0000958.md): Engine · making metal · Dec 11, 2024 · N454JH · Hughes 369E · Engine (Turbine/Turboprop)
  > PILOT EXPERIENCED AN ENGINE CHIP INDICATION DURING APPROACH. MAINTENANCE PERFORMED CLEANING AND GROUND RUNS AND RETURNED TO SERVICE.
- [SDR 2024FA0000554](https://openairdocs.org/sdr/2024FA0000554.md): Clutch · making metal · Jul 28, 2024 · N842JH · Hughes 369E · Engine/Transmission Coupling
  > DURING A SCHEDULED 100 HOUR MAINTENANCE INSPECTION ON THE AIRCRAFT. THE MECHANIC QUESTIONED THE DARK BURNT APPEARANCE OF THE GREASE IN THE • BEARING, OVERRUNNING CLUTCH BALL OUTPUT. PER OPERATOR REQUEST THE CLUTCH ASSEMBLY WAS DISASSEMBLED AND A SIGNIFICANT AM
- [SDR 2024FA0000495](https://openairdocs.org/sdr/2024FA0000495.md): Clutch · making metal · Jul 9, 2024 · N842JH · Hughes 369E · Main Rotor Drive System
  > DURING AIRCRAFT INSPECTION AN AIRCRAFT MECHANIC QUESTIONED DISCOLORING OF THE OVERRUNNING CLUTCH OUTPUT BEARING GREASE. THE BEARING DID NOT DEMONSTRATE ANY ABNORMAL PLAY OR ROUGHNESS. THE CLUTCH HAD THE CORRECT AMOUNT OF OIL INSTALLED. IT WAS DECIDED TO DISAS
- [SDR 2024FA0000203](https://openairdocs.org/sdr/2024FA0000203.md): Engine · making metal · Mar 6, 2024 · N454E · Hughes 369E · Engine (Turbine/Turboprop)
  > PILOT REPORTED AN ENGINE CHIP LIGHT ILLUMINATION AND PERFORMED AN UNSCEDULED LANDING. A MECHANIC WAS SENT TO THE AIRCRAFT AND DISCOVERED METAL ON THE UPPER ENGINE GEARBOX PLUG WITH A SIZE GREATER THAN EXCEPTABLE LIMITS FOR RETURN TO SERVICE. NOTHING FURTHER TO
- [SDR 3M3A202401060001](https://openairdocs.org/sdr/3M3A202401060001.md): Unknown · unknown · Jan 1, 2024 · N514PA · Hughes 369D · Powerplant System
  > ON JANUARY 1ST 2024, N514PA EXPERIENCED AN ENGINE CHIP LIGHT DURING A 135 TOUR FLIGHT. THE PILOT MADE A PRECAUTIONARY LANDING. ALL PASSENGERS WERE REMOVED WITH A SECOND HELICOPTER CARRYING MAINTENANCE PERSONNEL. LARGE CHUNKS OF ROLLER BEARING CAGE MATERIAL WER
- [SDR 2023FA0000497](https://openairdocs.org/sdr/2023FA0000497.md): Engine · abnormal · Aug 28, 2023 · N842JH · Hughes 369E · Engine (Turbine/Turboprop)
  > UDRING STRAIGHT AND LEVEL FLIGHT THE PILOT REPORTED LOW ENGINE TORQUE. THE PILOT SELECTED A LANDING SPOT AND PERFORMED AN UNEVENTFUL PRECAUTIONARY LANDING. THE AIRCRAFT WAS MOVED TO A MAINTENANCE LOCATION AND THE ENGINE WAS REMOVED FOR INSPECTION. NO CAUSE DET
- [SDR 2023FA0000285](https://openairdocs.org/sdr/2023FA0000285.md): Connector · loose · May 30, 2023 · N842JH · Hughes 369E · Engine Indicating System
  > DURING FLIGHT THE PILOT NOTICED THE FUEL QUANTITY GAUGE DROPPED TO ZERO THEN THE ENGINE OIL TEMP WENT TO ZERO. THE INSTRUMENT CIRCUIT BREAKER THEN POPPED. THE PILOT LANDED WITHOUT ISSUE. THE PILOT RESET THE CIRCUIT BREAKER ONCE SHUT DOWN AND MAINTENANCE COULD
- [SDR 2022FA0000760](https://openairdocs.org/sdr/2022FA0000760.md): Engine · making metal · Dec 14, 2022 · N454JH · Hughes 369E · Engine (Turbine/Turboprop)
  > ENGINE GEARBOX CHIP LIGHT ILLUMINATED DURING APPROACH FOR LANDING. UPON INSPECTION IT WAS DETERMINED THAT THE UPPER GEARBOX MAGNETIC CHIP DETECTOR HAD ILLUMINATED THE WARNING LIGHT WITH METAL ABOVE THE MAXIMUM ALLOWED. A SMALLER AMOUNT OF METAL WAS FOUND ON TH
- [SDR 2022FA0000677](https://openairdocs.org/sdr/2022FA0000677.md): Engine · making metal · Nov 8, 2022 · N454JH · Hughes 369E · Engine (Turbine/Turboprop)
  > PILOT GOT AN ENGINE CHIP LIGHT DURING FLIGHT AND PERFORMED A PRECAUTIONARY LANDING. MAINTENANCE FOUND EVIDENCE OF CHIPS ON THE LOWER AND UPPER ENGINE GEARBOX CHIP DETECTORS. ENGINE REMOVED FROM AIRCRAFT FOR INSPECTION.
- [SDR 2022FA0000286](https://openairdocs.org/sdr/2022FA0000286.md): Hub · cracked · Jun 10, 2022 · N6006K · Hiller UH12E · Main Rotor System
  > A CRACK WAS FOUND ON THE OUTSIDE OF M/R HUB ORIGINATING FROM INBOARD TT PIN HOLE. THE CRACK EXTENDS FROM THE INSIDE DIAMETER OF THE BORE TO THE OUTSIDE OF THE HUB. AFTER CLOSE EXAMINATION IT SEEMS THAT THERE ARE ROUGH MACHINING MARKS THAT CAUSED A STRESS CONCE
- [SDR K2DA0182E](https://openairdocs.org/sdr/K2DA0182E.md): Compressor · none · Nov 3, 2021 · N508PH · Doug MD500E · Engine (Turbine/Turboprop)
  > AIRCRAFT N508PH, A MD500E, WAS CONDUCTING A UTILITY FLIGHTS UNDER AN OAS CONTRACT AND PERFORMED A PRECAUTIONARY LANDING AT 21°35’ 10.9” N, 158° 00’ 44.7” W DUE TO SMOKE EMANATING FROM THE ENGINE. THE PILOT WAS THE ONLY OCCUPANT OF THE AIRCRAFT. AFTER LANDING
- [SDR 2021FA0000137](https://openairdocs.org/sdr/2021FA0000137.md): Turbine Wheel · binding · May 13, 2021 · N454JH · Hughes 369E · Turbine Section
  > DURING MAINTENANCE THE MECHANICS DETERMINED THE FIRST STAGE TURBINE BLADES WERE RUBBING ON THE NOZZLE.ASSEMBLY REMOVED FROM ENGINE
- [SDR 2021FA0000047](https://openairdocs.org/sdr/2021FA0000047.md): Fuel Control · failed · Feb 16, 2021 · N719CB · Bell 206B · Fuel Control/Turbine Engines
  > FIRST FUEL CONTROL UNABLE TO ADJUST START, SECOND FUEL CONTROL WAS UNABLE TO START AT ALL, REPLACED FUEL CONTROL DISCREPANCY WAS FIXED. THIS WAS ALL IN A YEARS TIME. ON AIRCRAFT 748 THE FUEL CONTROL WAS CHANGED DUE TO THE THROTTLE ARM WAS DIFFICULTY TO ROTATE
- [SDR 2021FA0000078](https://openairdocs.org/sdr/2021FA0000078.md): Fuel Control · failed · Feb 16, 2021 · N719CB · Bell 206B · Fuel Control/Reciprocating Engines
  > AIRCRAFT ENGINE WOULD NOT START. FUEL CONTROL REMOVED AND REPLACED DISCREPANCY CORRECTED. THIS IS THE FINDINGS OF THE REPAIR STATION THE FUEL CONTROL WAS SENT TO. THIS IS NOT THE SAME REPAIR STATION THAT THE FUEL CONTROL WAS OVERHAULED AT. THE FUEL CONTROL BEL
- [SDR 2019FA0000338](https://openairdocs.org/sdr/2019FA0000338.md): Fuel Control · leaking · Oct 14, 2019 · N808JH · Hughes 369E · Fuel Control/Turbine Engines
  > DURING MAINTENANCE GROUND RUN CHECK OPERATIONS ENGINE FUEL WAS NOTICED COMING OUT OF THE FUEL CONTROL CASE AND LEAKING TO THE GROUND. FUEL CONTROL WAS REMOVED FOR INVESTIGATION AND A SERVICABLE UNIT INSTALLED.
- [SDR 2019FA0000298](https://openairdocs.org/sdr/2019FA0000298.md): Coupling · broken · Sep 6, 2019 · N54528 · Hughes 369D · Tail Rotor Drive Shaft
  > FAILURE OF THE AFT COUPLING. FRACTURE OF COUPLING. SEE ENGINEERED PRODUCTS 8130-3 WORK ORDER # MDI1167 DATED MARCH 20, 2018 FOR PART DETAIL.
- [SDR CA190716006](https://openairdocs.org/sdr/CA190716006.md): Governor · faulty · Jul 10, 2019 · Bell 206B · Turbine Governor
  > (CAN) AIRCRAFT WAS IN FLIGHT AND PILOT NOTICED A DROP IN ENGINE RPM FROM 100% TO 90%. STARTED DECENT ON A BUSH ROAD. GOVERNOR WAS REPLACED WITH A SERVICEABLE UNIT. NO DAMAGE OR INJURY (TC# 20190716006)
- [SDR DCGA2019FA0000153](https://openairdocs.org/sdr/DCGA2019FA0000153.md): Engine · making metal · May 15, 2019 · N454JH · Hughes 369E · Engine (Turbine/Turboprop)
  > ENGINE CHIP LIGHT DURING FLIGHT. MAINTENANCE FOUND 4 FLAKES ON UPPER AND LOWER PLUGS WITHIN PARAMETERS. PERFORMED AN OIL SYSTEM DRAIN, FLUSH AND FILTER CLEAN AND CHANGE AND GROUND RUN. CHIP PLUGS WERE CLEAN UPON REINSPECTION. AIRCRAFT WAS RETURNED TO SERVICE.
- [SDR BHHR20190607001](https://openairdocs.org/sdr/BHHR20190607001.md): Housing · cracked · Apr 18, 2019 · N9749C · Hiller UH12E · Main Rotor Gearbox
  > A CRACK WAS FOUND IN TRANSMISSION LOWER HOUSING JUST BELOW THE CYCLIC BELLCRANK BRACKET P/N 33031 MOUNTING FACE. THE CRACK WAS LOCATED IN THE AFT LOWER MOUNTING BOSS FOR THE CYCLIC BRACKET IN THE FILLET OF THE LOWER HOUSING. SEE ATTACHED PICTURES. CORRECTIVE A
- [SDR K2DA2019052800001](https://openairdocs.org/sdr/K2DA2019052800001.md): Bleed Valve · stuck · Apr 17, 2019 · N58243 · Hughes 369D · Compressor Bleed Valve
  > PILOT PERFORMED ENGINE POWER ASSURANCE CHECK AT 80% TQ AND 2,000 FT AGL AND REPORTED A +1* ON THE POWER CHECK WHICH WAS A SIGNIFICANT DIFFERENCE IN THE POWER CHECK TAKEN THE DAY PRIOR (+30). UPON LANDING, MAINTENANCE PERSONNEL WERE CALLED AND IT WAS DISCOVERED
- [SDR CA190326009](https://openairdocs.org/sdr/CA190326009.md): Compressor · fod · Mar 26, 2019 · Hughes 369D · Turbine Engine Compressor Section
  > (CAN) THE RENTAL ENGINE RAN HOT FROM THE FIRST DAY I FLEW IT. THE STARTS WHERE VERY SLOW BUT STILL IN PARAMETERS. THE TOT WAS APPROX. 580 DEGREES AT GROUND IDLE AND 580-600 AT FLIGHT IDLE WITH 18-20 PSI TQ. THE SECOND STARTS WERE OK, THEY WOULD BE ON THE HOTTE
- [SDR K2DA2019052800003](https://openairdocs.org/sdr/K2DA2019052800003.md): Bleed Valve · sticks · Mar 19, 2019 · N545PH · Hughes 369E · Compressor Bleed Valve
  > DURING AN ROUTINE INSPECTION IT WAS DISCOVERED THAT THE ENGINE BLEED VALVE WAS STICKING. BLEED VALVE HAD 317.2 TSO.
- [SDR 2019FA0000075](https://openairdocs.org/sdr/2019FA0000075.md): Blade · cracked · Mar 18, 2019 · N808JH · Hughes 369E · Main Rotor Blades
  > THE BOTTOM SKIN OF THE MAIN ROTOR BLADE HAS A 4 1/2 INCH CRACK STATING AT THE TRAILING EDGE AND PERPENDICULAR TO SPAN 57 1/4 INCHES IN FOR BLADE TIP.
- [SDR CA190507012](https://openairdocs.org/sdr/CA190507012.md): Stator · broken · Mar 18, 2019 · Hughes 369D · Turbine Engine Compressor Section
  > (CAN) UPON ROUTINE INSPECTION OF COMPRESSOR CASE HALFS (WHILE ENGINE WAS REMOVED FROM AIRFRAME) IT WAS FOUND THAT ONE OF THE 6TH STAGE STATOR BLADES HAD BROKEN OFF ONE OF THE CASE HALFS AND BEEN INJESTED INTO THE COMPRESSOR CENTRIFUGAL COMPRESSOR SECTION, AND
- [SDR 2020FA0000049](https://openairdocs.org/sdr/2020FA0000049.md): Rotor · cracked · Mar 12, 2019 · N220GP · Bell 206B · Main Rotor System
  > A CRACK INDICATION WAS INDICATED 7/16 INCHES LONG, 10 INCHES FROM UPPER END OF MAST. CRACK WAS FOUND WITH FLORESCENT MAGNETIC PARTICLE. INSPECTION WAS DONE PER TASK, AS REQUESTED BY CLIENT.
- [SDR K2DA2019052800002](https://openairdocs.org/sdr/K2DA2019052800002.md): Bleed Valve · stuck · Feb 17, 2019 · N545PH · Hughes 369E · Compressor Bleed Valve
  > PILOT WAS RUNNING ENGINE ON THE GROUND AND THE COMPRESSOR STARTED STALLING. MAINTENANCE PERSONNEL DISCOVERED THE ENGINE BLEED VALVE WAS STUCK IN THE CLOSED POSITION. BLEED VALVE HAD 103.4 TSO. BLEED VALVE WAS CHANGED OUT AND THE ISSUE WENT AWAY.
- [SDR J5XA2019FA0000031](https://openairdocs.org/sdr/J5XA2019FA0000031.md): Chip Detector · contaminated · Feb 5, 2019 · N454JH · Hughes 369E · Turbine Engine Accessory Drive
  > PILOT REPORTED AN ENGINE CHIP LIGHT DURING APPROACH TO LANDING. MAINTENANCE FOUND ACCEPTABLE CHIPS ON UPPER AND LOWER PLUGS. THE PLUGS WERE CLEANED AND REINSTALLED AND A PENALTY RUN WAS PERFORMED. THE PLUGS WERE RECHECKED AND FOUND CLEAN. AIRCRAFT WAS RETURNED
- [SDR LSSA2018F00000](https://openairdocs.org/sdr/LSSA2018F00000.md): Drive Bearing · failed · Sep 20, 2018 · N16726 · Bell 206B · Fuel Control/Turbine Engines
  > THE AIRCRAFT SUFFERED AN INFLIGHT ENGINE OVERSPEED AND SUBSEQUENT ENGINE FAILURE. THE PILOT PERFORMED A SUCCESSFUL AUTOROTATION TO THE GROUND WITH NO DAMAGE TO THE AIRFRAME AND NO INJURIES TO THE OCCUPANTS. AFTER RECOVERY OF THE ACFT AND REMOVAL. INSPECTION
- [SDR CA190110019](https://openairdocs.org/sdr/CA190110019.md): Safety Valve · failed · Sep 19, 2018 · Bell 206B · Turbine Engine Compressor Section
  > (CAN) IT WAS REPORTED TO BELL: ENROUTE WITH A PASSENGER AND SUSTAINED A SUDDEN POWER LOSS. PILOT AUTOROTATED TO AN OPEN FIELD AND THE LANDING GEAR WAS DAMAGED DURING LANDING BUT AIRCRAFT REMAINED UPRIGHT. INVESTIGATION FOUND THE PC SAFETY VALVE HAD FAILED. NO
- [SDR MKHR2018091300000](https://openairdocs.org/sdr/MKHR2018091300000.md): Bolt · sheared · Aug 8, 2018 · N369MH · Hughes 369D · Tail Rotor Head
  > DURING CRUISE FLIGHT THE PILOT EXPERIENCED AN EXCESSIVE TAIL ROTOR VIBRATION. THE PILOT THEN EXECUTED A PRECAUTIONARY LANDING. WHEN CREW ARRIVED TO INVESTIGATE THE VIBRATION THE INITIAL DISCOVERED WAS THAT THE OUTBOARD TAIL ROTOR FORK BOLT WAS SHEARED.
- [SDR CA180723016](https://openairdocs.org/sdr/CA180723016.md): Monitor · cracked · Jul 19, 2018 · Bell 206B · Main Rotor Gearbox
  > (CAN) DURING SCHEDULED MAINTENANCE, THE TRANSMISSION OIL MONITOR HOUSING WAS REMOVED TO INSPECT THE SCREEN FOR CONTAMINATION. UPON REMOVAL OF THE O-RING FROM THE TRANSMISSION OIL MONITOR IT WAS DISCOVERED THAT THERE WAS CRACKING AROUND THE MOUNTING FLANGE OF
- [SDR DCGA2018071200221](https://openairdocs.org/sdr/DCGA2018071200221.md): Chip Detector · contaminated · Jul 12, 2018 · N842JH · Hughes 369E · Turbine Engine Accessory Drive
  > PILOT REPORTED AND ENGINE CHIP LIGHT AND PERFORMED AN UNSCHEDULED LANDING. MAINTENANCE FOUND 1 SLIVER ON THE UPPER GEARBOX CHIP PLUG. THE PLUG WAS CLEANED AND A PENALTY ENGINE RUN WAS PERFORMED IN REFERENCE TO THE ENGINE OMM. THE PLUGS WERE FOUND CLEAN AND THE
- [SDR DCGA201801230044](https://openairdocs.org/sdr/DCGA201801230044.md): Engine · making metal · Jan 23, 2018 · N842JH · Hughes 369E · Engine (Turbine/Turboprop)
  > DURING CRUISE FLIGHT AND ENGINE CHIP LIGHT INDICATION OCCURRED. THE PILOT PERFORMED A PRECAUTIONARY LANDING. MAINTENANCE DISCOVERED METAL FLAKES ON UPPER AND LOWER ENGINE CHIP PLUG. PER MAINTENANCE MANUAL INSTRUCTION IT WAS DETERMINED THAT THE ENGINE ASSEMBLY
- [SDR CA180117008](https://openairdocs.org/sdr/CA180117008.md): Drive Shaft · worn · Jan 8, 2018 · Bell 206B · Tail Rotor Drive Shaft
  > (CAN) NOTED A KNOCKING NOISE NEAR TAIL ROTOR GEARBOX AFTER AIRCRAFT LANDED FOR MAINTENANCE. FOUND EXCESSIVE PLAY BETWEEN AFT TAIL ROTOR DRIVESHAFT SEGMENT AND HANGER BEARING. DISASSEMBLED AFT SEGMENT AND FOUND WEAR ON BEARING MATING SURFACE OF THE SHAFT, AS
- [SDR HDNA2018F00066](https://openairdocs.org/sdr/HDNA2018F00066.md): Engine · making metal · Jan 3, 2018 · N915SH · Bolkms BO105S · Engine (Turbine/Turboprop)
  > ENGINE CHIP INDICATION. PILOT FOLLOWED EMERGENCY PROCEDURE AND SHUT ENGINE DOWN AND PERFORMED RUN-ON LANDING. UPON INSPECTION OF CHIP DETECTOR FOUND CATEGORY 1 SLUDGE TYPE MATERIAL. PERFORMED PENALTY RUN WITH NO DEFECTS NOTED.
- [SDR BHHR201710030001](https://openairdocs.org/sdr/BHHR201710030001.md): Drive Gear · spalled · Oct 3, 2017 · N3324F · Hiller UH12E · Engine (Turbine/Turboprop)
  > A TEAR-DOWN INSPECTION OF A 250-C20B ENGINE GEARBOX WAS PERFORMED. THIS GEARBOX WAS REMOVED FROM SERVICE DUE TO CHIP LIGHTS AND AN AUDIBLE WHINE HEARD OVER THE RUNNING AIRCRAFT. THIS GEARBOX WAS ASSEMBLED IN-HOUSE AFTER A 3500 HOUR OVERHAUL INSPECTION OF TH
- [SDR BHHR201710030002](https://openairdocs.org/sdr/BHHR201710030002.md): Gear · spalled · Oct 3, 2017 · N3324F · Hiller UH12E · Engine (Turbine/Turboprop)
  > ENGINE WAS REMOVED FROM SERVICE DUE TO CHIP LIGHTS AND AN AUDIBLE WHINE HEARD OVER THE RUNNING AIRCRAFT. THIS GEARBOX WAS ASSEMBLED IN-HOUSE AFTER A 3500 HOUR OVERHAUL INSPECTION OF THE GEARS WAS PERFORMED AN AUTHORIZED REPAIR FACILITY. PTO GEAR SHOWED SIG
- [SDR 2017F00107](https://openairdocs.org/sdr/2017F00107.md): Bearing · failed · Jul 17, 2017 · N401HP · Turbine Section
  > ENGINE CHIP LIGHT CAME ON, TURBINE WAS INSPECTED AND THE NR 5 BEARING WAS FOUND TO BE THE CAUSE OF METAL GENERATION.
- [SDR 2017FA0000000](https://openairdocs.org/sdr/2017FA0000000.md): Compressor · damaged · Jan 3, 2017 · N454JH · Hughes 369E · Turbine Engine Compressor Section
  > PILOT REPORTED TURBINE OUTLET TEMPERATURE INCREASE AT END OF FLIGHT. MAINTENANCE DISCOVERED COMPRESSOR BLADES DAMAGED BY UNKNOWN FOD.
- [SDR 2016FA0000632](https://openairdocs.org/sdr/2016FA0000632.md): Drive Assy · cracked · Dec 13, 2016 · Fuel Control/Turbine Engines
  > DRIVE BODY WAS FOUND CRACKED DURING OVERHAUL.
- [SDR 2016FA0000537](https://openairdocs.org/sdr/2016FA0000537.md): Fuel Control · leaking · Oct 24, 2016 · N454JH · Hughes 369E · Fuel Control/Turbine Engines
  > DURING A POST FLIGHT INSPECTION MAINTENANCE FOUND A SMALL FUEL LEAK AT THE OUT FITTING LOCATION ON THE ENGINE FUEL CONTROL UNIT. THE UNIT WAS REPLACED WITH A SERVICEABLE UNIT.
- [SDR QMLA2016071816076](https://openairdocs.org/sdr/QMLA2016071816076.md): Warning System · false activation · Jul 18, 2016 · N459AM · Bell 407 · Rotor Drive Indicating System
  > AFTER TAKEOFF, THE PILOT SAW A TRANSMISSION CHIP LIGHT ILLUMINATE. HE IMMEDIATELY RETURNED TO BASE AND CALLED THE MECHANIC ON DUTY. THE MECHANIC ARRIVED TO TROUBLESHOOT. HE DRAINED AND FLUSHED THE TRANSMISSION, CHANGED THE FILTER, CHECKED AND CLEANED ALL 3
- [SDR DCGA2016071800332](https://openairdocs.org/sdr/DCGA2016071800332.md): Blade · delaminated · Jul 16, 2016 · N633JH · Hughes 369E · Main Rotor Blades
  > FOUND DELAMINATION ON MAIN ROTOR BLADE STAINLESS STEEL LEADING EDGE.
- [SDR K2DA20160707146](https://openairdocs.org/sdr/K2DA20160707146.md): Bearing · spalled · Jul 4, 2016 · N58243 · Hughes 369D · Engine (Turbine/Turboprop)
  > AIRCRAFT PERFORMED A PRECAUTIONARY LANDING FOR AN ENGINE CHIP LIGHT WHILE CONDUCTING AN AIR TOUR. THERE WERE NO SECONDARY INDICATIONS AND THE AIRCRAFT LANDED SAFELY. AFTER CLEARING THE CHIP LIGHT IAW THE MANUAL, THE AIRCRAFT WAS FLOWN BACK TO BASE. IT WAS D
- [SDR K2D2016F00002](https://openairdocs.org/sdr/K2D2016F00002.md): Bearing · damaged · Jun 14, 2016 · N58243 · Hughes 369D · Accessory Gearboxes
  > THE COMPRESSOR WAS REMOVED FROM THE ENGINE GEARBOX AND IT WAS DISCOVERED THAT THE COMPRESSOR SPUR ADAPTER GEARSHAFT JOURNAL HAD A WORN AREA WHERE METAL WAS REMOVED. AFTER INSPECTION OF THE GEARBOX, IT WAS DETERMINED THAT THE 2.5 BEARING HAD FAILED AND WAS THE
- [SDR 2016FA0000284](https://openairdocs.org/sdr/2016FA0000284.md): Bearing · spalled · Jun 8, 2016 · Turbine Section
  > THE ENGINE WAS REMOVED FOR CHIPS IN THE OIL. THE SOURCE WAS FOUND TO BE THE NR 5 BEARING, PN M250-10106, SN NWL13-0863.
- [SDR HDNA201604270001](https://openairdocs.org/sdr/HDNA201604270001.md): Compressor · making metal · Apr 27, 2016 · N911LF · Bolkms BO105S · Turbine Engine Compressor Section
  > WHILE ON BASE FINAL FOR TAXIWAY, THE NR 1 ENG OIL PRESS STARTED FLUCTUATING WITH OIL TEMPERATURE NORMAL & TORQUES MATCHED. AT SHORT FINAL THE ENG CHIP CAUTION LIGHT ILLUMINATED, SIDE STEPPED THE RAMP & LANDED 100 YARDS SHORT OF NORMAL LANDING AREA. SHUTDOWN
- [SDR 8MHR201604110001](https://openairdocs.org/sdr/8MHR201604110001.md): Turbine Wheel · fractured · Apr 9, 2016 · Turbine Section
  > FOUND A PIECE OF THE FOURTH STAGE TURBINE WHEEL BLADE AND SHROUD MISSING.

Next page: https://openairdocs.org/engine/allison-250-c20b/reports.md?page=2

## The whole list in SQL

Runs in DuckDB 1.2 or later on the release's Parquet files over HTTPS:

```sql
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
```

This list as a web page: https://openairdocs.org/engine/allison-250-c20b/reports

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