# JASC 6720: Tail Rotor Control System - Type: JASC system/component code (FAA) - ATA chapter: 67 Rotors Flight Control - Title in the code table: TAIL ROTOR CONTROL SYSTEM - Service difficulty reports: 852 - FAA code table: https://www.faa.gov/sites/faa.gov/files/JASC_Code.pdf#page=59 - Page: https://openairdocs.org/jasc/6720 ## What it covers The components and system parts which control movement about the vertical axis. The directional control may be accomplished by changing the tail rotor blade angle, or by directed compressed air (i.e., NOTAR systems). Includes tail rotor control pedals, cables, rods, bellcranks, associated support brackets, compressed air ducts, valves, etc. ## Service difficulty reports (852, newest 50) - [SDR QR9R2026073000002](https://openairdocs.org/sdr/QR9R2026073000002), Jul 30, 2026: Bolkms BK117C2. ACTUATOR. FAULTY. DURING RUN-UP, YAW SAS AND BACKUP SAS CAUTIONS WOULD NOT GO OUT. DURING TROUBLESHOOTING, SHOT RESISTANCE BETWEEN PINS B - [SDR 8LFA202506170003](https://openairdocs.org/sdr/8LFA202506170003), Nov 7, 2025: Bell 429. BEARING. FAILED. TAIL ROTOR BLADE CONTROL PITCH LINK BEARING FAILED, THE INNER RACE SEPARATED FROM THE OUTER RACE, WHICH ALLOWED THE PITC (N433LF) - [SDR 2025FA0000426](https://openairdocs.org/sdr/2025FA0000426), Jun 25, 2025: Bell 407. PITCH LINK. WORN. RAPID WEAR OF TAIL ROTOR PITCH LINK (N14HX) - [SDR QR9R2025051400001](https://openairdocs.org/sdr/QR9R2025051400001), May 14, 2025: Bolkms BK117C2. CABLE. DAMAGED. AFTER RECEIVING PART FROM SUPPLY, MAINTENANCE DETECTED THE TAIL ROTOR FLEXBALL CABLE THREADS WERE DAMAGED ON FWD END AT (N556AH) - [SDR H11A2025062500425](https://openairdocs.org/sdr/H11A2025062500425), Apr 10, 2025: Bell 407. BEARING. WORN. RAPID WEAR OF TAIL ROTOR PITCH LINK BEARING (N46HX) - [SDR 2NVA202408210020](https://openairdocs.org/sdr/2NVA202408210020), Aug 18, 2024: Robsin R44. CONTROL ROD. DEFORMED. DURING ATTEMPTED ROTOR ENGAGEMENT FOLLOWING ENGINE START, TAIL ROTOR PEDALS DEFLECTED FULL LEFT. ENGINE WAS IMMEDIATELY (N740RH) - [SDR HEEA202310230001](https://openairdocs.org/sdr/HEEA202310230001), Oct 23, 2023: Skrsky S76C. RETAINING RING. DISLODGED. DURING CRUISE FLIGHT, WASHERS AND RETENTION RING WERE SEEN ON THE COPILOT FLOOR. DISCOVERED THE RIGHT TAIL ROTOR PEDAL W (N725P) - [SDR 2023FA0000282](https://openairdocs.org/sdr/2023FA0000282), May 30, 2023: Agusta AW119MKII. PIN. MALFUNCTIONED. DURING AN AVIONIC TEST FLIGHT THE TAIL ROTOR PEDAL LOCKOUT EXPANDABLE PIN FELL APART FROM THE PIN HANDLE. THERE ARE NO I (N319MC) - [SDR QR9R2023020700001](https://openairdocs.org/sdr/QR9R2023020700001), Feb 7, 2023: Bolkms BK117C2. ACTUATOR. OSCILLATES. IN STRAIGHT AND LEVEL FLIGHT, AIRCRAFT OSCILLATES IN YAW AXES. WHEN SAS CUT IS ACTIVATED, OSCILLATIONS STOP. REMOVED AND - [SDR QMLA2022120400484](https://openairdocs.org/sdr/QMLA2022120400484), Dec 4, 2022: Urocop EC130T2. PEDAL. BINDING. SHORTLY AFTER TAKE OFF, LEFT PEDAL WAS APPLIED WITH A BINDING IN THE PEDAL CONTROLS. AN UNUSUAL SOUND WAS COMING WHEN PE (N237SH) - [SDR QR9R20220715002](https://openairdocs.org/sdr/QR9R20220715002), Jul 15, 2022: Bolkms BK117C2. ACTUATOR. FAILED. #1 AP ACTUATOR FAILED 3 TIMES ON PREFLIGHT. REMOVED AND REPLACED SEMA ACTUATOR IAW AMM 67-20-00, 4-8. T/F SUCCESSFULLY C - [SDR QR9R20220629003](https://openairdocs.org/sdr/QR9R20220629003), Jun 29, 2022: Bolkms BK117C2. ACTUATOR. WARNING MESSAGE. DURING FLIGHT, AP1 FAIL AND ACTUATOR CAUTIONS ILLUMINATED. CONDUCTED EMERGENCY PROCEDURE BUT ACTUATOR CAUTION REMAINED O - [SDR 2022FA0000212](https://openairdocs.org/sdr/2022FA0000212), Apr 14, 2022: Airbus A300*. ACTUATOR. WRONG PART. IN ACCORDANCE WITH SB MBB-BK117 C-2-67-013, IF THE TAIL ROTOR ACTUATOR (P/N B673M40A1001 [TYPE 1]) IS REPLACED, IT WILL (N9383) - [SDR 2VKA2022030720221](https://openairdocs.org/sdr/2VKA2022030720221), Feb 16, 2022: Bell 407. PITCH LINK. CRACKED. DURING THE PREFLIGHT INSPECTION ONE OF THE BEARINGS ON THE TAIL ROTOR PITCH CHANGE LINK WAS FOUND WORN. THE BEARING STAR (N561SF) - [SDR QR9R20211022003](https://openairdocs.org/sdr/QR9R20211022003), Oct 22, 2021: Bolkms BK117C2. ACTUATOR. WARNING LIGHT. ACTUATOR LIGHT CAME ON IN FLIGHT WITH STIFFNESS IN THE CYCLIC, AUTO PILOT FAILED TEST AFTERWARDS AND THE YAW CODE CAME U - [SDR 2021F00282](https://openairdocs.org/sdr/2021F00282), Oct 1, 2021: Airbus EC135P3. LEVER. WORN. ON MANY EC135 SERIES AIRFRAMES, EXCESSIVE WEAR HAS BEEN NOTED ON A PRIMARY FLIGHT CONTROL LEVER. SPECIFICALLY THE TAIL R - [SDR QR9R20210721001](https://openairdocs.org/sdr/QR9R20210721001), Jul 21, 2021: Bolkms BK117C2. TRIM MOTOR. UNRELIABLE. DURING FUNCTIONAL CHECK FLIGHT FOR TAIL ROTOR BALANCE AND SLEEVE REPLACEMENT YAW ACTUATOR FAILED. ATTEMPTED SEVERAL RESE (N404AE) - [SDR Z1RA76110232020](https://openairdocs.org/sdr/Z1RA76110232020), Oct 23, 2020: Skrsky S76D. SERVO. LEAKING. TAIL ROTOR SERVO LEAKING AT SHAFT SEAL. (N761AF) - [SDR YV3R2020110900377](https://openairdocs.org/sdr/YV3R2020110900377), Oct 8, 2020: Robsin R22BETAII. PITCH CONTROL. NOISY. CUSTOMER REPORTED PITCH CONTROL ASSEMBLY P/N: A031-1 HAD BEARING NOISE. - [SDR YV3R2020091700346](https://openairdocs.org/sdr/YV3R2020091700346), Sep 11, 2020: Robsin R44RAVENII. PITCH CONTROL. DEFECTIVE. CUSTOMER REPORTED TAIL ROTOR PITCH CONTROL P/N: C031-1 HAD AN UNUSUAL BEARING NOISE AFTER ENGINE SHUT DOWN, WHILE DRIVE - [SDR YV3R2020082900335](https://openairdocs.org/sdr/YV3R2020082900335), Jul 16, 2020: Robsin R66. PUSH-PULL ROD. WORN. CORRECTED (UNIQUE CONTROL #): CUSTOMER REPORTED PUSH-PULL TUBE P/N: C121-17 WAS WORN AT FORWARD GUIDE POSITION. - [SDR YV3R2020082800335](https://openairdocs.org/sdr/YV3R2020082800335), Jul 16, 2020: Robsin R66. PUSH-PULL ROD. WORN. CUSTOMER REPORTED PUSH-PULL TUBE P/N: C121-17 WAS WORN AT FORWARD GUIDE POSITION. - [SDR 2A6R2019121655001](https://openairdocs.org/sdr/2A6R2019121655001), Dec 16, 2019: Urocop EC135T2. FLEX COUPLING. SEPARATED. DURING HEAVY MAINTENANCE, FOUND THE TAIL ROTOR FLEXBALL CABLE OUTER SHEATH AT THE AFT END TO BE BROKEN AND SEPARATED FRO (N916LH) - [SDR HDNA201911189494](https://openairdocs.org/sdr/HDNA201911189494), Nov 8, 2019: Bolkms BK117C2. ACTUATOR. FAULTY. PILOT REPORTED AN ACTUATOR WARNING LIGHT ILLUMINATED ON THE CENTRAL PANEL DISPLAY SYSTEM WITH NO SECONDARY INDICATIONS O (N145UC) - [SDR YV3R2019012320203](https://openairdocs.org/sdr/YV3R2019012320203), Oct 8, 2019: Robsin R44. BEARING. ROUGH. CUSTOMER REPORTED TAIL ROTOR PITCH CONTROL P/N: C031-1 HAS ROUGH BEARINGS. - [SDR 11RR20190820767](https://openairdocs.org/sdr/11RR20190820767), Aug 15, 2019: Doug 600N. CABLE. BROKEN. ON TAKEOFF PILOT REALIZED HE HAD NO ANTI-TORQUE INPUT WITH LEFT PEDAL INPUT. THE PILOT LOWERED THE COLLECTIVE IMMEDIATEL (N507CC) - [SDR HDNA2019071800001](https://openairdocs.org/sdr/HDNA2019071800001), Jul 18, 2019: Snias AS350B3. BEARING RACE. CRACKED. THE TAIL ROTOR CONTROL ROD PN 350A27-1910-0401 AFT BEARING RACE CRACKED. (N464RM) - [SDR CA190626014](https://openairdocs.org/sdr/CA190626014), Jun 24, 2019: Robsin R44RAVENII. BEARING. FAILED. (CAN) DURING LAST SHUT DOWN OF THE DAY THE PILOT NOTED THAT ON WHINED DOWN THERE WAS A SQUEAL COMING FROM THE BACK OF TH - [SDR 2019FA0000124](https://openairdocs.org/sdr/2019FA0000124), Apr 13, 2019: Doug MD500N. CONTROL CABLE. BINDING. A/C EXPERIENCED STUCK RIGHT PEDAL IN FLIGHT RESULTING IN EMERGENCY LANDING. UPON INSPECTION OF ANTI-TORQUE SYSTEM, FOUND (N523HB) - [SDR 2018FA0000380](https://openairdocs.org/sdr/2018FA0000380), Sep 10, 2018: Agusta AW109SP. ROCKER. LOOSE. DURING A WALK AROUND INSPECTION THE TECHNICIAN NOTICED THAT THE ROCKER ARM ASSEMBLY ON THE TAIL ROTOR HUB ASSEMBLY WAS V (N22284) - [SDR 2018FA0000193](https://openairdocs.org/sdr/2018FA0000193), Jun 20, 2018: Bell UH1H. QUILL. DISCONNECTED. AIRCRAFT EXPERIENCED A LOSS OF TAIL ROTOR CONTROL DURING FLIGHT REQUIRING THE PILOT TO CONDUCT A HOVERING AUTOROTATION T (N777S) - [SDR 2A6R20171121005](https://openairdocs.org/sdr/2A6R20171121005), Nov 21, 2017: Urocop EC135T2. CONTROL TUBE. CRACKED. A CRACK WAS DISCOVERED PROPAGATING FROM THE FORWARD END OF THE TUBE PART OF THE CONTROL ROD, WHERE THE END IS RIVETED ON (N914TH) - [SDR JYDR20170811215](https://openairdocs.org/sdr/JYDR20170811215), Aug 10, 2017: Skrsky S64E. SERVO. LOCKED. TAIL ROTOR GEAR BOX & SERVO ASSY RECEIVED WITH A WRITE-UP OF UNABLE TO CHANGE PITCH OF BLADES BY HAND DURING INSPECTION. - [SDR M3XA2017071301](https://openairdocs.org/sdr/M3XA2017071301), Jul 13, 2017: Urocop EC135P2. PEDAL. OUT OF ALIGNMENT. EXPERIENCED A PEDAL PROBLEM WHILE ON APPROACH TO LANDING. PILOT NOTICED THAT THE PEDALS SEEMED MISALIGNED FROM THEIR NOR (N135LX) - [SDR AC2R2017031001](https://openairdocs.org/sdr/AC2R2017031001), Mar 2, 2017: Skrsky S92A. ROD END. DAMAGED. FOUND TAIL ROTOR PITCH CHANGE SHAFT (PCS)- INPUT CONTROL TUBE ROD END BEARING OUTER RING WAS NO LONGER SECURE IN THE ROD (N921GL) - [SDR CA160215013](https://openairdocs.org/sdr/CA160215013), Feb 14, 2016: Hughes 369D. SUPPORT. BROKEN. (CAN) DURING INSPECTION OF FRONT PEDAL SUPPORT IT WAS NOTED THAT BOTH UPPER TANGS OF THE LEFT PEDAL SUPPORT WERE BROKEN - [SDR QMLA2016010216001](https://openairdocs.org/sdr/QMLA2016010216001), Jan 2, 2016: Snias AS350B2. ACCUMULATOR. LOW PRESSURE. THE PILOT & MEDICAL CREW WERE ENROUTE TO AN ACCIDENT SCENE WHEN THE PILOT FELT SOME FEEDBACK IN THE TAIL ROTOR PEDALS. A (N577AM) - [SDR EVCA201601125](https://openairdocs.org/sdr/EVCA201601125), Dec 31, 2015: Bell 206L1. BELLCRANK. DAMAGED. TAIL ROTOR CONTROL BELLCRANK LOCATED UNDER TAIL ROTOR GEARBOX HAS MECHANICAL DAMAGE WHERE THE LONG TAIL ROTOR CONTROL TU (N106AE) - [SDR CA150914004](https://openairdocs.org/sdr/CA150914004), Sep 11, 2015: Agusta AW139. BEARING. DEBONDED. (CAN) Y9-Y10 BELLCRANK, BEARING FOUND DISBONDED FROM HOUSING DURING ROUTINE INSPECTION. - [SDR QMLA2015090415082](https://openairdocs.org/sdr/QMLA2015090415082), Sep 4, 2015: Agusta AW119MKII. BEARING. CRACKED. DURING A0521 NT, 100 HR TAIL ROTOR INSPECTION, WAS REMOVING THE TAIL ROTOR CROSS HEAD ASSEMBLY & FOUND THE BLADE END PC (N354LL) - [SDR CA150824009](https://openairdocs.org/sdr/CA150824009), Aug 22, 2015: Bell 429. LINK. BROKEN. (CAN) DURING FLIGHT THE PILOT NOTED A BUMP AND THEN AN IMMEDIATE VIBRATION. AUTOPILOT WAS TURNED OFF AND THE ACFT WAS SL - [SDR CA150615023](https://openairdocs.org/sdr/CA150615023), Jun 13, 2015: Snias AS350B2. SPIDER. SEIZED. (CAN) PERFORMING 100HR INSPECTION ON ACFT. REMOVED T/R PITCH LINKS & SPIDER LINK. CHECKED SPIDER ASSEMBLY FOR FREEDOM OF - [SDR 3UWR201503160001](https://openairdocs.org/sdr/3UWR201503160001), Feb 27, 2015: Bell 429. PITCH LINK. OUT OF TOLERANCE. TAIL ROTOR PITCH LINK HAS LESS THEN 300 HOURS TIME IN SERVICE AND THE ROLL STAKE BEARING HAS APPROX. 1/8 INCH OF PLAY. I (N429) - [SDR CA150313012](https://openairdocs.org/sdr/CA150313012), Feb 19, 2015: Robsin R44RAVENII. GREASE. FROZEN. (CAN) TAIL ROTOR PEDALS INCLEASINGLY STIFF DURING FLIGHT, NO MECHANICAL OBSTRUCTION FOUND. PEDAL BEARING BLOCK GREASE FR - [SDR CA150224032](https://openairdocs.org/sdr/CA150224032), Nov 30, 2014: Snias AS350B3. BUSHING. DAMAGED. (CAN) TAIL ROTOR ASSY, WAS REMOVED TO FACILITATE REPLACEMENT OF PITCH HORN ASSY, PN 355A12-5102-00 X 2. UPON REMOVAL, TH - [SDR CA141008013](https://openairdocs.org/sdr/CA141008013), Oct 7, 2014: Bell 429. FLT CONTROLS. MALFUNCTIONED. (CAN) IN PREPARATION FOR CONTINUED PRODUCTION FLIGHT TESTING, ALL WAS NORMAL. DURING FLIGHT TESTING IN THE MORNING OF TH - [SDR CA140903012](https://openairdocs.org/sdr/CA140903012), Aug 24, 2014: Hughes 369D. BEARING. ROUGH. (CAN) AFTER LANDING AND DURING ENGINE WIND DOWN, A LOUD SQUEAL WAS HEARD COMING FROM THE AFT OF THE HELICOPTER. IT WAS D - [SDR CA140723001](https://openairdocs.org/sdr/CA140723001), Jul 21, 2014: Agusta AW139. PEDAL. STIFF. (CAN) TAIL ROTOR CONTROL PEDALS STIFF IN FLIGHT, ABNORMAL FORCE REQUIRED. - [SDR CA140715009](https://openairdocs.org/sdr/CA140715009), Jul 15, 2014: Bell 407. SOLENOID. INOPERATIVE. (CAN) WATER ENTRAPMENT CAUSED THE PEDAL STOP SOLENOID TO BECOME INOPERATIVE. WHEN THE LOWER WSPS PANEL WAS OPEN, WATER W - [SDR HLXR2014FA0000369](https://openairdocs.org/sdr/HLXR2014FA0000369), May 7, 2014: Doug 600N. DRUM. CRACKED. FOUND CRACKS ON DRUM ASSEMBLY DURING TWO YEAR INSPECTION ON FLIGHT CONTROLS. TWO POSTS HAD ONE CRACK EACH, RUNNING HALF (N605BP) All 852: https://openairdocs.org/jasc/6720/reports.md ## Other codes in chapter 67 - [JASC 6700](https://openairdocs.org/jasc/6700): Rotorcraft Flight Control (317 reports) - [JASC 6710](https://openairdocs.org/jasc/6710): Main Rotor Control (1,151 reports) - [JASC 6711](https://openairdocs.org/jasc/6711): Tilt Rotor Flight Control (11 reports) - [JASC 6730](https://openairdocs.org/jasc/6730): Rotorcraft Servo System (647 reports) - [JASC 6797](https://openairdocs.org/jasc/6797): Rotors Flight Control System Wiring (9 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.