# Service difficulty reports: JASC 6320

A list on [JASC 6320](https://openairdocs.org/jasc/6320.md).

Reports filed under 6320 · Main Rotor Gearbox, newest first.

Page 1 of 39 · 1,930 reports

- [SDR QMLA2026070420042](https://openairdocs.org/sdr/QMLA2026070420042.md): Transmission · making metal · Jul 3, 2026 · N865NC · Urocop EC135P2
  > XMSN CHIP ILLUMINATED AT PICKUP HOSPITAL. MISSION WAS ABORTED, DID NOT STARTUP WITH TRANSMISSION CAUTION. CONTACTED MECHANIC TO FIX ON STATION. INSPECTED CHIP CONFIRMED CAT C RTS
- [SDR JTAA20260504001](https://openairdocs.org/sdr/JTAA20260504001.md): Transmission · fod · May 4, 2026 · N825WL · Skrsky S61N
  > DURING FLIGHT HAD LOW TRANSMISSION PRESSURE AND ELS SYSTEM KICKED ON. FOUND MGB LINER MATERIAL IN CHIP DETECTOR SCREEN OF MGB.
- [SDR 2026F00097](https://openairdocs.org/sdr/2026F00097.md): Transmission · fod · May 4, 2026 · N825WL · Skrsky S61N
  > DURING FLIGHT HAD LOW TRANSMISSION PRESSURE AND ELS SYSTEM KICKED ON. FOUND MGB LINER MATERIAL IN CHIP DETECTOR SCREEN OF MGB.
- [SDR QMLA2026040620026](https://openairdocs.org/sdr/QMLA2026040620026.md): Transmission · making metal · Mar 29, 2026 · N528AM · Bell 407
  > TRANSMISSION CHIP LIGHT IN FLIGHT. DRAINED AND FLUSHED SYSTEM. OPS CHECKS GOOD RTS,
- [SDR QMLA2026032020021](https://openairdocs.org/sdr/QMLA2026032020021.md): Warning Light · false activation · Mar 20, 2026 · N645AM · Bell 407
  > TRANSMISSION CHIP LIGHT ON ROLL UP TO FLIGHT. REMOVED AND INSPECTED ALL TRANSMISSION CHIP DETECTORS FOUND NO METAL DURING REINSTALL OF LOWER CHIP DETECTOR CHIP LIGHT CAME ON. TESTED LOWER CHIP DETECTOR FOUND IT HAD INTERNALLY FAILED.
- [SDR 2026FA0000161](https://openairdocs.org/sdr/2026FA0000161.md): Transmission · making metal · Mar 5, 2026 · N454JH · Hughes 369E
  > PILOT REPORTED INTERMITTENT MAIN GEARBOX CHIP LIGHT DURING APPROACH TO LANDING. MAGNETIC PLUG INSPECTION REVEALED METAL CONTAMINATION BEYOND ACCEPTABLE LIMITS AND TRANSMISSION WAS REMOVED FOR REPAIR.
- [SDR QMLA2026012520005](https://openairdocs.org/sdr/QMLA2026012520005.md): Chip Detector · false activation · Jan 23, 2026 · N473RA · Bell 407
  > TRANSMISSION CHIP LIGHT CAME ON DURING APPROACH. CLEANED CHIP, GROUND RUN ACCOMPLISHED IAW DMC-407-A-63-00-00-0/A-319 TABLE 1
- [SDR 2026FA0000002](https://openairdocs.org/sdr/2026FA0000002.md): Gearbox · warning light · Jan 4, 2026 · N540SF · Bolkms BK117D3
  > DURING FLIGHT MGB CHIP LIGHT ILLUMINATED. PILOT ATTEMPTED TWO ATTEMPTS AT BURNING THE CHIP. LIGHT REMAINED ON SO PILOT ELECTED TO MAKE AN UNSCHEDULED LANDING AT A NEARBY AIRPORT.
- [SDR HEEA202510300001](https://openairdocs.org/sdr/HEEA202510300001.md): Chip Detector · dirty · Oct 25, 2025 · N673P · Airbus H160B
  > DURING FLIGHT THE DISPATCH MESSAGE XMSN: MGB CHIP FRT AGB SENSOR DISPLAYED, CREW INITIATED RTB.
- [SDR HEEA202509220001](https://openairdocs.org/sdr/HEEA202509220001.md): Gearbox · making metal · Sep 19, 2025 · N673P · Airbus H160B
  > DURING CLIMB OUT, NOTICED A MGB CHIP DISPATCH MESSAGE.
- [SDR CHIA202508149805](https://openairdocs.org/sdr/CHIA202508149805.md): Transmission · overheated · Aug 14, 2025 · N246CH · Boeing 234
  > THE NR 2 ENGINE TRANSMISSION TEMPERATURE EXCEEDED UPPER TEMPERATURE LIMIT IN FLIGHT RESULTING IN PILOTS INITIATING ENGINE XMSN HOT EMERGENCY PROCEDURES AND RETURNING TO BASE FOR AN UNSCHEDULED LANDING. REMOVED THE NR 2 ENGINE TRANSMISSION ASSEMBLY AS UNSERVIC
- [SDR QMLA2025070220071](https://openairdocs.org/sdr/QMLA2025070220071.md): Gearbox · warning message · Jul 2, 2025 · N328CH · Urocop EC130B4
  > MAIN ROTOR GEARBOX CHIP LIGHT ILLUMINATED IN FLIGHT: 4TH RECENT EVENT.
- [SDR QMLA2025062920070](https://openairdocs.org/sdr/QMLA2025062920070.md): Gearbox · making metal · Jun 29, 2025 · N328CH · Urocop EC130B4
  > MGB CHIP LIGHT ILLUMINATED DURING STABLE 3-5FT HOVER PRIOR TO TAKEOFF. INSPECTED AND CLEANED MGB CHIP DETECTOR. CLASS F CHIP FOUND. PERFORMED GROUND RUN UP WITH NO CHIPS DETECTED. ALL MAINTENANCE COMPLETED. AIRCRAFT RELEASED TO REVENUE SERVICE. #MEC-011620
- [SDR HEEA202505270002](https://openairdocs.org/sdr/HEEA202505270002.md): Transmission · making metal · May 25, 2025 · N454PH · Bell 407
  > TRANSMISSION CHIP LIGHT ILLUMINATED IN FLIGHT, RETURNED TO DEPARTURE POINT.
- [SDR QMLA2025052020058](https://openairdocs.org/sdr/QMLA2025052020058.md): Gearbox · making metal · May 20, 2025 · N328CH · Urocop EC130B4
  > MAIN ROTOR GEARBOX CHIP 'MGB CHIP' LIGHT ILLUMINATED IN FLIGHT. INSPECTED FOUND 1 CLASS F PARTICLE. - GROUND RUN CW - OPS CHECK GOOD.
- [SDR QMLA2025051520056](https://openairdocs.org/sdr/QMLA2025051520056.md): Gearbox · warning light · May 16, 2025 · N328CH · Urocop EC130B4
  > MAIN ROTOR GEAR BOX CHIP INDICATOR LIGHT ILLUMINATED IN FLIGHT. FIRST SET OF FLIGHTS FROM CHANGING OF MBG OIL FILTER YESTERDAY.
- [SDR QMLA2025051020054](https://openairdocs.org/sdr/QMLA2025051020054.md): Transmission · warning light · May 9, 2025 · N338AM · Bell 407
  > TRANSMISSION MAIN ROTOR CHIP LIGHT.
- [SDR HEEA202504100001](https://openairdocs.org/sdr/HEEA202504100001.md): Transmission · making metal · Apr 7, 2025 · N448PH · Bell 407
  > ENROUTE TO SM76, TRANSMISSION CHIP LIGHT ILLUMINATED INFLIGHT. CONTACTED COMM CENTER AND FOUND NEAREST AVAILABLE PLATFORM TO LAND. NO SECONDARY INDICATIONS. DAY MECHANIC PERFORMED CHIP LIGHT INVESTIGATION OFFSHORE. CLEANED AND INSPECTED TRANSMISSION CHIP DETEC
- [SDR QMLA2025031720036](https://openairdocs.org/sdr/QMLA2025031720036.md): Chip Detector · contaminated · Mar 17, 2025 · N697AM · Bell 407
  > INTERMITTENT TRANSMISSION CHIP LIGHT IN FLIGHT. FOUND SMALL SLIVERS ON LOWER CHIP DETECTOR. AMOUNT AND TYPE CONSIDERED NEGLIGIBLE. - CHANGED FILTER.
- [SDR QMLA2025020220011](https://openairdocs.org/sdr/QMLA2025020220011.md): Gearbox · making metal · Feb 2, 2025 · N136HN · Urocop EC135P2
  > XMSN CHIP LIGHT ILLUMINATED ON DEPARTURE.
- [SDR HEEA202501200001](https://openairdocs.org/sdr/HEEA202501200001.md): Gearbox · making metal · Jan 17, 2025 · N151PH · Agusta AW139
  > ON CLIMB OUT, GOT A MAIN GEARBOX CHIP CAS MSG. BURNED IT THREE TIMES AND CAME ON A FOURTH TIME.
- [SDR HEEA202501020001](https://openairdocs.org/sdr/HEEA202501020001.md): Gearbox · making metal · Dec 31, 2024 · N932PH · Skrsky S92A
  > LN CRUISE ON A FLIGHT FROM HMA TO GB-386 POSEIDON, A MGB CHLP CAUTION ILLUMINATED, FOLLOWED BY INPUT 2 CHIP CAUTION APPROXIMATELY 4 MINUTES LATER. CREW DEVIATED TO KHUM UPON FIRST CAUTION.
- [SDR HEEA202411260001](https://openairdocs.org/sdr/HEEA202411260001.md): Transmission · making metal · Nov 22, 2024 · N406PH · Bell 407
  > SHORTLY AFTER TAKEOFF WHILE IN CRUISE FLIGHT, CHIP XMSN LIGHT ILLUMINATED. RETURNED TO HMAE.
- [SDR KY1R20241101001](https://openairdocs.org/sdr/KY1R20241101001.md): Cooling Fan · separated · Nov 1, 2024 · N382MD · Agusta AW139
  > DURING A COMPANY-MANDATED DAILY INSPECTION OF THE AIRCRAFT, A TECHNICIAN FOUND THE OUTLET SCREEN FOR THE MAIN GEARBOX (MGB) OIL COOLER FAN WAS BROKEN WITH THE WELDED MESH SPLAYED OUTWARD. FURTHER INVESTIGATION REVEALED THAT THE MGB OIL COOLER FAN CONTAINMENT
- [SDR QMLA2024101520132](https://openairdocs.org/sdr/QMLA2024101520132.md): Transmission · making metal · Oct 12, 2024 · N535LN · Urocop EC135P2
  > MAIN XMSN CHIP ILLUMINATED ON START. CLEANED MAG CHIP DETECTOR ENGINE RUNS COMPLETE. IAW AMM 63-40-00
- [SDR 2024FA0000762](https://openairdocs.org/sdr/2024FA0000762.md): Bearing · wrong part · Oct 9, 2024 · Hughes 369
  > WHILE INSTALLING X4 'OVERHAULED' ACCESSORY BEARINGS ONTO ACCESSORY SHAFT, ENGINEER NOTICED THE ID OF X2 BEARINGS WERE SIGNIFICANTLY SMALLER THAN THE ID OF THE OTHER 2 BEARINGS. X4 ACCESSORY BEARINGS P/N: 369F5149-1 SENT TO PAS MRO FOR OVERHAUL ON JOB/40834 (J
- [SDR MHR22024092400733](https://openairdocs.org/sdr/MHR22024092400733.md): Bearing · flaking · Sep 24, 2024 · N216MH · Bell 206L4
  > TRANSMISSION ASSEMBLY HAD METAL IN OIL.
- [SDR HEEA202409230001](https://openairdocs.org/sdr/HEEA202409230001.md): Gearbox · making metal · Sep 22, 2024 · N940PH · Skrsky S92A
  > #1 INPUT CHIP LIGHT ILLUMINATED.
- [SDR QMLA2024092420124](https://openairdocs.org/sdr/QMLA2024092420124.md): Gearbox · making metal · Sep 21, 2024 · N534LN · Urocop EC135P2
  > MAIN TRANSMISSION CHIP LIGHT DETECTOR ILLUMINATED. OIL PRESSURE STEADY
- [SDR HEEA202407290001](https://openairdocs.org/sdr/HEEA202407290001.md): Transmitter · inoperative · Jul 26, 2024 · N725P · Skrsky S76C
  > DURING CRUISE FLIGHT THE MGB PRESSURE INDICATION BEGAN TO FLUCTUATE BETWEEN 65PSI TO 0 PSI. AIRCRAFT RETURNED TO BASE.
- [SDR 2VKA2024072453407](https://openairdocs.org/sdr/2VKA2024072453407.md): Washer · cracked · Jul 23, 2024 · N390SF · Bell 407
  > WHILE CHANGING TRANSMISSION ASSEMBLY, TECHNICIAN NOTICED PYLON RETAINING BOLT WASHER PN:140-007-25S22E6 CRACKED ALL THE WAY THROUGH ON ONE SIDE.
- [SDR HEEA202407150001](https://openairdocs.org/sdr/HEEA202407150001.md): Sensor · inoperative · Jul 11, 2024 · N936PH · Skrsky S92A
  > ON OUTBOUND LEG, DURING CLIMB OUT, MGB PRESSURE INCREASED INTO THE PRECAUTIONARY (YELLOW) RANGE. RTB, DECLARED EMERGENCY, LANDED RUNWAY 36 AT HOUMA.
- [SDR QMLA2024062520071](https://openairdocs.org/sdr/QMLA2024062520071.md): Bypass Valve · faulted · Jun 23, 2024 · N586AM · Urocop EC135P2
  > THE PILOT PICKED UP PATIENT AS DESIGNATED LZ/SCENE AND DEPARTED THE SCENE FOR DESERT REGIONAL MEDICAL CENTER. WHILE ON CLIMB OUT (AROUND 1000') OVER MOUNTAINOUS TERRAIN, PILOT SCANNED ENGINE & TRANSMISSION TEMPS & PRESSURES. WHEN PILOT LOOKED AT NR 1 ENG COLU
- [SDR M3XA20240425006](https://openairdocs.org/sdr/M3XA20240425006.md): Transmission · making metal · Apr 24, 2024 · N516MT · Bell 407
  > PILOT PERFORMED A PRECAUTIONARY LANDING FOR A MAIN XMSN CHIP LIGHT ILLUMINATION IN CRUISE FLIGHT. MECHANIC INSPECTED CHIP DETECTORS AND FOUND A SMALL SLIVER. CLEANED CHIP DETECTOR AND PERFORMED A SERVICEABILITY CHECK. DRAINED AND SERVICED WITH NEW OIL, REPL
- [SDR QMLA2024042220040](https://openairdocs.org/sdr/QMLA2024042220040.md): Transmission · making metal · Apr 13, 2024 · N697AM · Bell 407
  > MAIN TRANSMISSION CHIP LIGHT ILLUMINATED IN FLIGHT DURING CLIMB SHORTLY AFTER TAKEOFF. PILOT ABORTED FLIGHT AND RETURNED TO THE BASE. MECHANIC PERFORMED UNWANTED PARTICLE INSPECTION AND FOUND ONE SLIVER. NORMAL FINDINGS AFTER MAJOR MAINTENANCE (MAST REPLACEME
- [SDR AC2R921GL03192024](https://openairdocs.org/sdr/AC2R921GL03192024.md): Bushing · cracked · Mar 19, 2024 · N921GL · Skrsky S92A
  > THREE OF THE BUSHINGS ON THE RH MOUNTING FOOT WAS FOUND TO BE FRACTURED.
- [SDR 2024FA0000135](https://openairdocs.org/sdr/2024FA0000135.md): Oil Cooler · sheared · Feb 6, 2024 · N455MH · Bolkms BK117C2
  > #2 ENG OIL COOLER, SUSPECTED SHAFT BROKEN. REPORTED #2 ENG OIL TEMP FLUCTUATION. INSP REVEALED #2 ENG OIL COOLER SHAFT SHEARED. REM'D #2 OIL COOLER FAN ASSY. INSTALLED SERVICEABLE FAN ASSY, P/N SAME. PERFORMED GROUND RUN/LEAK CHK W/NO ANOMALIES. ACFT RETURNED
- [SDR HEEA202401310001](https://openairdocs.org/sdr/HEEA202401310001.md): Transmission · making metal · Jan 30, 2024 · N794P · Skrsky S76C
  > MAIN GEAR BOX CHIP LIGHT CAME ON. ALL OTHER INDICATIONS WERE NORMAL, RESET CIRCUIT BREAKER, AND LIGHT REMAINED ON. AIRCRAFT RETURNED TO HOUMA.
- [SDR 7ALA202407240174](https://openairdocs.org/sdr/7ALA202407240174.md): Washer · cracked · Jan 24, 2024 · N314SF · Bell 407
  > DURING TRANSMISSION CHANGE TECHNICIANS FOUND THREE PYLON RETAINING BOLT WASHERS PN:140-007-25S22E6 ALL CRACKED ACROSS ONE SIDE ALL THE WAY THROUGH.
- [SDR 7ALA2024F00175](https://openairdocs.org/sdr/7ALA2024F00175.md): Washer · cracked · Jan 24, 2024 · N314SF · Bell 407
  > DURING TRANSMISSION CHANGE TECHNICIANS FOUND THREE PYLON RETAINING BOLT WASHERS PN:140-007-25S22E6 ALL CRACKED ACROSS ONE SIDE ALL THE WAY THROUGH.
- [SDR 2023FA0000809](https://openairdocs.org/sdr/2023FA0000809.md): Seal · failed · Dec 5, 2023 · N553XB · Skrsky S76D
  > DURING INSPECTION FOUND MGB LOWER MAST SEAL IS LEAKING.
- [SDR QMLA2023101220089](https://openairdocs.org/sdr/QMLA2023101220089.md): Chip Detector · unknown · Oct 13, 2023 · N138HN · Urocop EC135P2
  > PILOT ARRIVED AT GRANT MEMORIAL HOSPITAL. HE SHUT DOWN AND AFTER ABOUT 30 MINUTES, HE APPLIED POWER TO THE AIRCRAFT. AFTER APPLYING BATTERY POWER, BUT BEFORE ENGINE START, THE PILOT NOTICED THE "XMSN CHIP" CAUTION WAS ILLUMINATED. HE POWERED DOWN THE AIRCRAFT
- [SDR YV3R2023111500585](https://openairdocs.org/sdr/YV3R2023111500585.md): Gearbox · defective · Sep 29, 2023 · Robsin R22BETAII
  > CUSTOMER REPORTED MAIN ROTOR GEARBOX P/N: A006-6 WAS MAKING METAL.
- [SDR 2023F00280](https://openairdocs.org/sdr/2023F00280.md): Gearbox · bypassing · Sep 18, 2023 · N940PH · Skrsky S92A
  > ON CLIMB OUT FROM HMA, THE MGB BYPASS LIGHT ILLUMINATED. PERFORMED EP AND RETURNED FOR LANDING.
- [SDR AC2A2023062213901](https://openairdocs.org/sdr/AC2A2023062213901.md): Actuator · unserviceable · Jun 18, 2023 · N639MM · Agusta AW139
  > ROTOR BRAKE FAIL CAS ILLUMINATED ON SHUT DOWN WITH CALIPER INDICATING DOWN POSITION. REPLACED ROTOR BRAKE ACTUATOR.
- [SDR JYDR20230413094](https://openairdocs.org/sdr/JYDR20230413094.md): Bevel Gear · cracked · Apr 12, 2023 · Skrsky S64E
  > MAIN GEAR BOX RECEIVED AT THIS REPAIR STATION FOR OVERHAUL. DURING THE OVERHAUL PROCESS THE MAIN BEVEL GEAR WAS FOUND TO HAVE A TOTAL OF 18 CRACKS. CRACKS FOUND BY MAGNETIC PARTIAL INSPECTION. THIS IS THE FIRST TIME THIS REPAIR STATION HAS FOUND CRACKS IN THIS
- [SDR 2023FA0000361](https://openairdocs.org/sdr/2023FA0000361.md): Fitting · sheared · Mar 27, 2023 · N412VC · Bell 412EP
  > DURING CRUISE FLIGHT EXPERIENCED A TOTAL LOSS OF ALL MAIN ROTOR TRANSMISSION FLUID DUE TO FAILURE OF 1 ELBOW FITTING (P/N: AS1040W0404). EMERGENCY LANDING PERFORMED WITH NO DAMAGE TO AIRCRAFT OR INJURY TO ANY OCCUPANTS. DURING CONVERSATIONS WITH THE OEM (BELL
- [SDR 8NZY202301180001](https://openairdocs.org/sdr/8NZY202301180001.md): Planetary Gear · damaged · Jan 18, 2023 · N350HC · Snias AS350B2
  > WHILE INSPECTING ONE OF THE FIVE PLANETARY GEARS. THE ENGINEER NOTICED A RING LIKE PATTERN ON ONE OF THE TEETH. WHEN THEY RUBBED THE AREA WITH THEIR FINGERNAIL TO SEE IF THE STAIN WAS PERMANENT A CHIP OF METAL FELL AWAY.
- [SDR 2023FA0000024](https://openairdocs.org/sdr/2023FA0000024.md): Transmission · making metal · Jan 11, 2023 · N416CF · Bell 407
  > TRANSMISSION CHIP LIGHT ILLUMINATED, FOUND METAL DEBRIS ON LOWER CHIP DETECTOR
- [SDR EVCA20221115001](https://openairdocs.org/sdr/EVCA20221115001.md): Hose · split · Nov 11, 2022 · N891GT · Urocop EC130T2
  > MAIN GEARBOX PRESSURE LIGHT ILLUMINATED WHILE IN CRUISE FLIGHT, CABIN FILLED WITH SMOKE. COMPLETE LOSS OF TRANSMISION OIL NOTED AFTER SHUT DOWN.. DISCOVERED TRANSMISSION OIL LINE TO COOLER SPLIT.

Next page: https://openairdocs.org/jasc/6320/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 jasc_code = '6320'
ORDER BY difficulty_date DESC
```

This list as a web page: https://openairdocs.org/jasc/6320/reports

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.