# JASC 6300: Main Rotor Drive System

- Type: JASC system/component code (FAA)
- ATA chapter: 63 Main Rotor Drive
- Title in the code table: MAIN ROTOR DRIVE SYSTEM
- Service difficulty reports: 637
- FAA code table: https://www.faa.gov/sites/faa.gov/files/JASC_Code.pdf#page=57
- Page: https://openairdocs.org/jasc/6300

## What it covers

For general reports of main rotor drive system with insufficient information to file in a more specific JASC sub-system code. Excessive use of this code should be avoided if possible.

## Service difficulty reports (637, newest 50)

- [SDR QMLA2026091420065](https://openairdocs.org/sdr/QMLA2026091420065), Sep 14, 2026: Bell 429. CHIP DETECTOR. INOPERATIVE. XMSN CHIP DETECTOR INOP CAME ON TWICE IN FLIGHT AND WENT OUT BEFORE LANDING, DURING RETURN LEG TO BASE, AFTER HALFWAY PO (N429HF)
- [SDR 2026FA0000648](https://openairdocs.org/sdr/2026FA0000648), Aug 17, 2026: Skrsky S58JT. COUPLING. CRACKED. CRACKED AROUND METAL ON COUPLING (N4247V)
- [SDR 8HBR20260830086](https://openairdocs.org/sdr/8HBR20260830086), Aug 10, 2026: Robsin R22BETA. SPRAG CLUTCH. DAMAGED. PILOTS FOUND A TEAR IN ONE OF THE DRIVE V-BELTS. UPON INSPECTION OF THE CLUTCH ASSEMBLY, THE UPPER SHEAVE HAD A SHARP ST (N924SH)
- [SDR EVCA202607011](https://openairdocs.org/sdr/EVCA202607011), Jul 1, 2026: Bell 407. WARNING LIGHT. FALSE ACTIVATION. DEPARTED HOSPITAL, XSMN CHIP LIGHT ILLUMINATED APPROX 2 MIN AFTER DEPARTURE. ABORTED FLIGHT, CONDUCTED PRECAUTIONARY EME (N728AE)
- [SDR QMLA2026032720024](https://openairdocs.org/sdr/QMLA2026032720024), Mar 27, 2026: Urocop EC135P2. WARNING MESSAGE. ILLUMINATED. TRANSMISSION CHIP CAUTION ILLUMINATED MULTIPLE TIMES WHILE IN CRUISE FLIGHT. CAUTION REMAINED ON FOR LAST 3 MINUTES OF F (N819LF)
- [SDR 2026FA0000086](https://openairdocs.org/sdr/2026FA0000086), Feb 5, 2026: Doug 600N. SPRAG ASSY. SLIPPED. THE REPAIR STATION REPORTED COMPLETION OF AN OVERHAUL ON AN OVERRUNNING CLUTCH ASSY, OVERHAUL RECORDS INDICATE THAT BEAR (N745B)
- [SDR 2025FA0000701](https://openairdocs.org/sdr/2025FA0000701), Oct 10, 2025: Robsin R22BETAII. SHEAVE. WORN. UPPER ANODIZED SHEAVE P/N A170-1 WORN. REQUIRES REPLACEMENT OF CLUTCH SHAFT ASSEMBLY P/N A018-1 (N115LE)
- [SDR 2025FA0000700](https://openairdocs.org/sdr/2025FA0000700), Oct 10, 2025: Robsin R22BETAII. SHEAVE. WORN. UPPER ANODIZED SHEAVE WORN. REQUIRES REPLACEMENT OF CLUTCH SHAFT ASSEMBLY. (N150LE)
- [SDR HEEA202501070001](https://openairdocs.org/sdr/HEEA202501070001), Jan 2, 2025: Bolkms BK117D2EURO. GEARBOX. CHIPPED. AFTER LEVEL OFF AT 6000' OUTBOUND, APPROXIMATELY 15NM SOUTH OF HOUMA, MGB CHIP CAUTION CAME ON. PERFORMED "CHIP PULSE" P (N393PH)
- [SDR 2025FA0000698](https://openairdocs.org/sdr/2025FA0000698), Sep 24, 2024: Robsin R22BETAII. SHEAVE. WORN. UPPER ANODIZED SHEAVE WORN. REQUIRES REPLACEMENT OF CLUTCH SHAFT ASSEMBLY. (N3040K)
- [SDR 2024FA0000495](https://openairdocs.org/sdr/2024FA0000495), Jul 9, 2024: Hughes 369E. CLUTCH. MAKING METAL. DURING AIRCRAFT INSPECTION AN AIRCRAFT MECHANIC QUESTIONED DISCOLORING OF THE OVERRUNNING CLUTCH OUTPUT BEARING GREASE.  (N842JH)
- [SDR M3XA2024070130009](https://openairdocs.org/sdr/M3XA2024070130009), Jun 30, 2024: Bell 407. TRANSMISSION. MAKING METAL. PILOT REPORTED A MAIN XMSN CHIP LIGHT IN FLIGHT AND PERFORMED A PRECAUTIONARY LANDING IN MANHATTAN, KS WITHOUT INCIDENT. (N516MT)
- [SDR M3XA20240629008](https://openairdocs.org/sdr/M3XA20240629008), Jun 29, 2024: Bell 407. TRANSMISSION. MAKING METAL. PILOT REPORTED A MAIN XMSN CHIP LIGHT IN FLIGHT AND PERFORMED A PRECAUTIONARY LANDING WITHOUT INCIDENT. MECHANIC INSPECT (N516MT)
- [SDR QMLA2024010320001](https://openairdocs.org/sdr/QMLA2024010320001), Jan 2, 2024: Urocop EC135T2. UNKNOWN. UNKNOWN. XMSN CHIP LIGHT ILLUMINATED WHILE IN CRUISE FLIGHT. I CHECKED THE TRANSMISSION OIL PRESSURE WHICH SEEMED TO BE FLUCTUATI (N958AL)
- [SDR 2023FA122200001](https://openairdocs.org/sdr/2023FA122200001), Dec 19, 2023: Hughes 369E. TRANSMISSION. INSTALLED. DURING A 135 TOUR OPERATION EXPERIENCED A MAIN ROTOR TRANSMISSION CHIP LIGHT RESULTING IN A PRECAUTIONARY LANDING. ANOTH (N716KV)
- [SDR QMLA2023120520111](https://openairdocs.org/sdr/QMLA2023120520111), Dec 2, 2023: Bolkms BK117C2. TRANSMITTER. UNKNOWN. DURING RETURN FLIGHT FROM BAYSTATE HOSPITAL BACK TO BASE, WHILE OVER BRADLEY AIRPORT (KBDL) THE RIGHT-SIDE MAIN ROTOR TR (N145HH)
- [SDR YV3R2023120100591](https://openairdocs.org/sdr/YV3R2023120100591), Nov 20, 2023: Robsin R22BETAII. ACTUATOR. DEFECTIVE. CUSTOMER REPORTED ACTUATOR ASSEMBLY P/N: A051-1 DOES NOT RETRACT WHEN SWITCH IS TURNED TO THE OFF POSITION AFTER FLIGHT.
- [SDR 2025FA0000699](https://openairdocs.org/sdr/2025FA0000699), Oct 4, 2023: Robsin R22BETAII. SHEAVE. WORN. UPPER ANODIZED SHEAVE P/N A170-1 WORN. REQUIRES REPLACEMENT OF CLUTCH SHAFT ASSEMBLY P/N A018-1 (N552LE)
- [SDR 2023F00338](https://openairdocs.org/sdr/2023F00338), Aug 29, 2023: Bell 206L4. LINK. UNKNOWN. PILOT REPORTED HEARING A LOUD (THUMP NOISE) WHEN THE AIRCRAFT WAS PICKED UP TO A HOVER DURING REPOSITIONING FROM ONE HEL (N53ZA)
- [SDR YV3R2023092900579](https://openairdocs.org/sdr/YV3R2023092900579), Aug 25, 2023: Robsin R44RAVENII. ACTUATOR. DEFECTIVE. CUSTOMER REPORTED ACTUATOR ASSEMBLY P/N: C051-2 ONLY HAD ONE TENSION PLATE WORKING.
- [SDR 2023FA0000664](https://openairdocs.org/sdr/2023FA0000664), Aug 24, 2023: Hughes 369F. BEARING RACE. CRACKED. F-DUTCH OUTER RACO PIN 369F5453-1 SIN 5640-0834 WAS ROTUMED FROM NDE PROFESSIONALS. INC. AS REJECTED DUO TO THREE MARKED (N530WH)
- [SDR QR9R2023080900007](https://openairdocs.org/sdr/QR9R2023080900007), Aug 9, 2023: Bolkms BK117C2. TRANSDUCER. FAILED. AFTER 2 HOURS INTO FLIGHT #1 TRANSMISSION PRESSURE INDICATION WENT TO .7 THEN TO NORMAL (CENTER OF BLACK), THEN WENT TO 
- [SDR QMLA2023080620058](https://openairdocs.org/sdr/QMLA2023080620058), Aug 5, 2023: Bell 407. TRANSMISSION. UNKNOWN. TRANSMISSION CHIP LIGHT ILLUMINATED IN FLIGHT. FOUND INSIGNIFICANT DEBRIS, AS DEFIED IN BELL MM, CHAPTER 63. (N408LN)
- [SDR QMLA2023072520055](https://openairdocs.org/sdr/QMLA2023072520055), Jul 25, 2023: Bell 407. TRANSMISSION. MAKING METAL. XMSN CHIP LIGHT CAME ON DURING CRUISE FLIGHT. (N223AM)
- [SDR 8HBR20230730053](https://openairdocs.org/sdr/8HBR20230730053), Jun 5, 2023: Robsin R22. SEAL. FAULTY. +DURING A 100 HOUR INSPECTION IT WAS FOUND THAT THE AFT SPRAG CLUTCH SEAL WAS MIGRATING OUT OF THE RETAINER HOUSING. (N924SH)
- [SDR YV3R2023071000575](https://openairdocs.org/sdr/YV3R2023071000575), May 30, 2023: Robsin R44. CLUTCH. FAULTY. CUSTOMER REPORTED HEAVY YAW MOVEMENTS WITH LOUD NOISES, C018-4 CLUTCH ASSEMBLY HAS ALUMINUM AND STEEL PARTICLES IN OIL.
- [SDR YV3R2023061400571](https://openairdocs.org/sdr/YV3R2023061400571), May 19, 2023: Robsin R44. SWITCH. DEFECTIVE. CUSTOMER REPORTED SWITCHES ASSEMBLY P/N: C053-2 HAS LOOSE CONNECTIONS.
- [SDR YV3R2023061400569](https://openairdocs.org/sdr/YV3R2023061400569), May 18, 2023: Robsin R22BETAII. ACTUATOR. DEFECTIVE. CUSTOMER REPORTED ACTUATOR ASSEMBLY P/N: A051-1 STOPS AND STARTS WHEN UNDER LOW COMPRESSION. (N938SH)
- [SDR 2023F00149](https://openairdocs.org/sdr/2023F00149), May 18, 2023: Skrsky S92A. MODULE. CHIPPED. APPROXIMATELY 18 MILES FROM KHUM THE #2 INPUT CHIP LIGHT ILLUMINATED. EMERGENCY PROCEDURES WERE PERFORMED AND WE CONTINU (N950PH)
- [SDR YV3R2023051000566](https://openairdocs.org/sdr/YV3R2023051000566), Apr 28, 2023: Robsin R22BETAII. ACTUATOR. DEFECTIVE. CUSTOMER REPORTED ACTUATOR ASSEMBLY P/N: A051-1 SPRINGS ARE NOT WORKING.
- [SDR QMLA2023042520033](https://openairdocs.org/sdr/QMLA2023042520033), Apr 24, 2023: Bell 407. TRANSMISSION. UNKNOWN. WHILE IN CRUISE FLIGHT, TRANSMISSION CHIP DETECTOR LIGHT ILLUMINATED ALONG WITH A CAUTION LIGHT AND AUDIBLE ALERT.LANDED (N208AM)
- [SDR YV3R2023042700556](https://openairdocs.org/sdr/YV3R2023042700556), Apr 5, 2023: Robsin R22BETAII. ACTUATOR. DEFECTIVE. CUSTOMER REPORTED ACTUATOR ASSEMBLY P/N: A051-1 OPERATES INTERMITTENTLY. (N476AT)
- [SDR QMLA2023031520014](https://openairdocs.org/sdr/QMLA2023031520014), Mar 15, 2023: Urocop EC130T2. V-BELT. UNKNOWN. PL DUE TO ILLUMINATION OF SERVO AND HYD2 CAUTION LIGHT. CAUTION LIGHTS ILLUMINATED WHILE AT CRUISE FLIGHT. PL CONDUCTED  (N240SH)
- [SDR HDNA20230222001](https://openairdocs.org/sdr/HDNA20230222001), Feb 21, 2023: Bolkms BK117B1. SWASHPLATE. CRACKED. DURING THE PERFORMANCE OF A DAILY AIRWORTHINESS CHECK THE MAIN ROTOR SWASHPLATE SUPPORT WAS FOUND CRACKED. CRACKS ARE NO (N117CH)
- [SDR 2023F00059](https://openairdocs.org/sdr/2023F00059), Feb 18, 2023: Bell 407. TRANSMISSION. CHIPPED. DURING CRUISE, TRANSMISSION CHIP LIGHT ILLUMINATED. AT APPROXIMATELY 1310 IN CRUISE FLIGHT AT 1250FT ENROUTE TO EI11H, T (N418PH)
- [SDR YV3R2023031500552](https://openairdocs.org/sdr/YV3R2023031500552), Feb 16, 2023: Robsin R44RAVENII. ACTUATOR. DEFECTIVE. CUSTOMER REPORTED ACTUATOR ASSEMBLY P/N: C051-2 FAILED SWITCH TEST.
- [SDR QR9R2023020700002](https://openairdocs.org/sdr/QR9R2023020700002), Feb 7, 2023: Bolkms BK117C2. TRANSMITTER. WARNING LIGHT. UPON STARTING THE #1 ENGINE, #1 TRANSMISSION OIL PRESSURE INDICATED 0. #2 OIL PRESSURE WAS 1.4. REMOVED AND REPLACED #1 
- [SDR QMLA2023011120003](https://openairdocs.org/sdr/QMLA2023011120003), Jan 6, 2023: Snias AS350B3. FRICTION RING. DAMAGED. FOUND ON PRE-FLIGHT SUSPECT MOVEMENT BETWEEN SWASHPLATE UNI-BALL AND MAST AT TEFLON OUTER FRICTION RING. THE CORRECTIVE  (N493LG)
- [SDR YV3R2022092300541](https://openairdocs.org/sdr/YV3R2022092300541), Sep 15, 2022: Robsin R22BETAII. SHEAVE. DEFECTIVE. CUSTOMER REPORTED SHEAVE (LOWER) P/N: A493-1 HAS BUBBLING UNDER METALIZING MATERIAL.
- [SDR QMLA2022082920059](https://openairdocs.org/sdr/QMLA2022082920059), Aug 26, 2022: Airbus A300*. NONE. NONE. DURING CRUISE FLT M/T CHIP CAUTION ILLUMINATED. 30 SECONDS LATER BATT DISCONNECT CAUTION ILLUMINATED. AIRCRAFT LANDED WI (N916LH)
- [SDR QR9R20220801001](https://openairdocs.org/sdr/QR9R20220801001), Aug 1, 2022: Bolkms BK117C2. FILTER. DAMAGED. AFTER RECEIVING PART FROM SUPPLY AND PRIOR TO INSTALLATION, MAINTENANCE DETECTED THE FILTER ASSEMBLY MATING SURFACE WAS 
- [SDR YV3R2022091300534](https://openairdocs.org/sdr/YV3R2022091300534), Jul 28, 2022: Robsin R22BETAII. ACTUATOR. DEFECTIVE. CUSTOMER REPORTED ACTUATOR ASSEMBLY P/N: A051-1 WAS INTERMITTENT IN OPERATION.
- [SDR EVCA202207220002](https://openairdocs.org/sdr/EVCA202207220002), Jul 22, 2022: Bell 407. MAST. CORRODED. CORROSION FOUND INSIDE MAST DURING 12 MONTH INSPECTION (N726AE)
- [SDR 8HBR20220722045](https://openairdocs.org/sdr/8HBR20220722045), Jul 20, 2022: Robsin R22BETA. SEAL. FAULTY. PILOT FOUND THE AFT SPRAG CLUTCH SEAL MIGRATED OUT OF THE RETAINER DURING HIS POST FLIGHT INSPECTION. (N8340S)
- [SDR EVCA202207220001](https://openairdocs.org/sdr/EVCA202207220001), Jul 20, 2022: Bell 407. MAST. CORRODED. CORROSION FOUND INSIDE MAST DURING 12 MONTH INSPECTION (N715AE)
- [SDR EVCA2022072100001](https://openairdocs.org/sdr/EVCA2022072100001), Jul 20, 2022: Bell 407. MAST. CORRODED. CORROSION FOUND INSIDE MAST ON 12 MONTH INSPECTION (N196AE)
- [SDR QMLA2022071220040](https://openairdocs.org/sdr/QMLA2022071220040), Jul 11, 2022: Snias AS350B2. GEARBOX. WARNING LIGHT. WE WERE RETURNING TO BASE AFTER COMPLETING AN INTERFACILITY TRANSFER. WE WERE FLYING ALONG, MINDING OUR OWN BUSINESS WHE (N563AM)
- [SDR QMLA2022051620028](https://openairdocs.org/sdr/QMLA2022051620028), May 13, 2022: Bell 407. NONE. USED. INTERMITTENT TRANSMISSION CHIP LIGHT. TRANSMISSION CHANGED OUT AT ACFT TT 2605+37 ON DATE 4/21/2022. INSPECTED CHIP DECT (N357AM)
- [SDR QR9R20220420001](https://openairdocs.org/sdr/QR9R20220420001), Apr 20, 2022: Bolkms BK117C2. BRAKE PADS. DAMAGED. AIRCRAFT RESTRICTED FROM USE OF ROTOR BRAKE DUE TO ROTOR BRAKE TOOK EXCESSIVE AMOUNT OF TIME, 3 MINUTES (25-50 SECONDS N
- [SDR 2022F00174](https://openairdocs.org/sdr/2022F00174), Mar 31, 2022: Snias AS350B2. DRIVE GEAR. CRUSHED. DURING A GROUND RUN IN PREPARATION FOR A FERRY FLIGHT, THE PILOT FELT A SIGNIFICANT VIBRATION IN THE AIRFRAME ACCOMPANIE (N352EV)

All 637: https://openairdocs.org/jasc/6300/reports.md

## Other codes in chapter 63

- [JASC 6310](https://openairdocs.org/jasc/6310): Engine/Transmission Coupling (772 reports)
- [JASC 6320](https://openairdocs.org/jasc/6320): Main Rotor Gearbox (1,930 reports)
- [JASC 6321](https://openairdocs.org/jasc/6321): Main Rotor Brake (275 reports)
- [JASC 6322](https://openairdocs.org/jasc/6322): Rotorcraft Cooling Fan System (213 reports)
- [JASC 6330](https://openairdocs.org/jasc/6330): Main Rotor Transmission Mount (603 reports)
- [JASC 6340](https://openairdocs.org/jasc/6340): Rotor Drive Indicating System (265 reports)
- [JASC 6397](https://openairdocs.org/jasc/6397): Main Rotor Drive System Wiring (17 reports)

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