# Keystone Helicopter S-76C

- Type: Aircraft model (FAA registry)
- Registry codes: 4900105, 4900103
- Manufacturer (registry): KEYSTONE HELICOPTER CORP · KEYSTONE HELICOPTER
- Model: S-76C
- Aircraft type: Rotorcraft
- Category: Rotorcraft
- Engines: 2 · Turbo-shaft
- Seats: 19
- Weight class: Up to 12,499 lb
- Certification: Type certificated
- Data sheet: [TCDS H1NE](https://openairdocs.org/tcds/H1NE) (OpenAirDocs)
- Holder: Sikorsky Aircraft Corporation
- Registered aircraft: 23
- Page: https://openairdocs.org/model/keystone-helicopter-s-76c

Model codes come from the FAA registry's reference file. ADs are matched to them by model name and maker. The FAA lists this model under more than one registry code, usually for different spellings of the maker. This page covers them all.

## ADs that may apply (OpenAirDocs)

Matched to this model by model name and maker. Each AD's applicability may narrow it by serial number, part number or equipment.

- [AD 2024-20-07](https://openairdocs.org/ad/2024-20-07): Emergency Equipment; Emergency Flotation Section · Apical Emergency Float Kit, P/N 20498 (STC SR00780LA or 12 others). Effective Dec 5, 2024
- [AD 2023-11-07](https://openairdocs.org/ad/2023-11-07): Ground Proximity System · Airbus Helicopters 47, 206, 210 and 237 more. Effective Jun 22, 2023
- [AD 2022-05-10](https://openairdocs.org/ad/2022-05-10): Cabin Equipment/Furnishings · Airbus Helicopters AS332L, AS332L1, AS332L2 and 57 more. Effective Apr 20, 2022
- [AD 2020-15-17](https://openairdocs.org/ad/2020-15-17): Indicating/recording system · Sikorsky S-76C. Effective Sep 9, 2020
- [AD 2019-19-12](https://openairdocs.org/ad/2019-19-12): Engine Fuel and Control · Sikorsky S-76C. Effective Nov 8, 2019
- [AD 2017-19-01](https://openairdocs.org/ad/2017-19-01): Rotorcraft Flight Control · Sikorsky S-76A, S-76B, S-76C and 1 more. Effective Jan 2, 2018
- [AD 2015-26-10](https://openairdocs.org/ad/2015-26-10): Main Rotor Gearbox · Sikorsky S-76A, S-76B and S-76C. Effective Feb 9, 2016
- [AD 2015-19-51](https://openairdocs.org/ad/2015-19-51): Flight Control System · Sikorsky S-76A, S-76B, S-76C and 1 more. Effective Nov 10, 2015
- [AD 2015-04-05](https://openairdocs.org/ad/2015-04-05): Tail Rotor Drive Shaft · Sikorsky S-76A, S-76B, S-76C and 1 more. Effective Mar 12, 2015
- [AD 2014-08-06](https://openairdocs.org/ad/2014-08-06): Main Rotor Head · Sikorsky S-76A, S-76B and S-76C. Effective Jun 2, 2014
- [AD 2013-22-15](https://openairdocs.org/ad/2013-22-15): Main Rotor Head · Sikorsky S-76A, S-76B and S-76C. Effective Dec 13, 2013
- [AD 2013-06-51](https://openairdocs.org/ad/2013-06-51): Equipment/Furnishings · Agusta A109, A109A, A109A II and 43 more. Effective Jul 15, 2013
- [AD 2012-22-13](https://openairdocs.org/ad/2012-22-13): Engine Controls · Sikorsky S-76C. Effective Dec 20, 2012
- [AD 2010-26-09](https://openairdocs.org/ad/2010-26-09): Navigation · Sikorsky S-76A, S-76B and S-76C. Effective Jan 12, 2011
- [AD 2010-17-16](https://openairdocs.org/ad/2010-17-16): Vertical Stabilizer · Sikorsky S-76A, S-76B and S-76C. Effective Oct 18, 2010
- [AD 2010-10-02](https://openairdocs.org/ad/2010-10-02): Servo actuator · Sikorsky S-76A, S-76B and S-76C. Effective Jun 17, 2010
- [AD 2010-07-02](https://openairdocs.org/ad/2010-07-02): Integrated navigation units (INUs) · 328 Support Services 328-100, 328-300, Jetstream Model 4101 and 26 more. Effective May 3, 2010
- [AD 2010-06-08](https://openairdocs.org/ad/2010-06-08): Emergency flotation system squib connector · Sikorsky S-76C. Effective Apr 1, 2010
- [AD 2007-11-05](https://openairdocs.org/ad/2007-11-05): Main rotor shaft assembly (M/R shaft) · Sikorsky S-76A, S-76B and S-76C. Effective Jun 15, 2007
- [AD 2004-06-04](https://openairdocs.org/ad/2004-06-04): Dual channel autopilot and dual inverters · Sikorsky S-76A, S-76B and S-76C. Effective Apr 15, 2004
- [AD 2003-14-18](https://openairdocs.org/ad/2003-14-18): Main landing gear brake discs (discs) · Sikorsky S-76A, S-76B and S-76C. Effective Aug 25, 2003
- [AD 2003-04-15](https://openairdocs.org/ad/2003-04-15): Rotor Brake Disc (RBD) · Sikorsky S-76A, S-76B and S-76C. Effective Feb 27, 2003
- [AD 2002-21-07](https://openairdocs.org/ad/2002-21-07): Main rotor spindle attachment bolt · Sikorsky S-76A, S-76B and S-76C. Effective Nov 25, 2002
- [AD 2002-15-51](https://openairdocs.org/ad/2002-15-51): Main rotor blade · Sikorsky S-76A, S-76B and S-76C. Effective Oct 18, 2002
- [AD 2001-25-06](https://openairdocs.org/ad/2001-25-06): AHRS WARN Circuits · Sikorsky S-76B and S-76C. Effective Jan 4, 2002
- [AD 2001-10-06](https://openairdocs.org/ad/2001-10-06): Main Rotor Shaft Assembly · Sikorsky S-76A, S-76B and S-76C. Effective Jun 21, 2001
- [AD 2001-03-51](https://openairdocs.org/ad/2001-03-51): Main Rotor Shafts · Sikorsky S-76B and S-76C. Effective Mar 21, 2001
- [AD 2001-01-04](https://openairdocs.org/ad/2001-01-04): Rod Assembly · Sikorsky S-76A, S-76B and S-76C. Effective Feb 2, 2001
- [AD 2000-11-52](https://openairdocs.org/ad/2000-11-52): Main Rotor Blade · Sikorsky S-76A, S-76B and S-76C. Effective Aug 31, 2000
- [AD 99-19-30](https://openairdocs.org/ad/99-19-30): Tail Gearbox Forward Fairing · Sikorsky S-76A, S-76B and S-76C. Effective Oct 4, 1999
- [AD 99-07-01](https://openairdocs.org/ad/99-07-01): Rotorcraft Flight Manual - Operating Limitations · Sikorsky S-76C. Effective Apr 7, 1999
- [AD 99-01-09](https://openairdocs.org/ad/99-01-09): Fuel Supply Line · Sikorsky S-76C. Effective Mar 3, 1999
- [AD 98-17-15](https://openairdocs.org/ad/98-17-15): Swashplate Assembly Uniball Bearing Retainer Inspection · Sikorsky S-76A, S-76B and S-76C. Effective Feb 1, 1999

Historical (superseded or no longer in force):

- [AD 2021-23-13](https://openairdocs.org/ad/2021-23-13) (historical): Ground Proximity System · Airbus Helicopters K-225, K-190A, K-240 and 237 more. Effective Dec 9, 2021
- [AD 2018-10-07](https://openairdocs.org/ad/2018-10-07) (historical): Engine Controls · Sikorsky S-76C. Effective Jun 25, 2018
- [AD 2010-11-52](https://openairdocs.org/ad/2010-11-52) (historical): Navigation system · Sikorsky S-76A, S-76B and S-76C
- [AD 2006-22-05](https://openairdocs.org/ad/2006-22-05) (historical): Integrated navigation units (INUs) · 328 Support Services 328-100, 328-300, Jetstream Model 4101 and 27 more. Effective Dec 1, 2006
- [AD 2005-22-01](https://openairdocs.org/ad/2005-22-01) (historical): Main rotor lower bifilar arm assembly · Sikorsky S-76A, S-76B and S-76C. Effective Nov 10, 2005
- [AD 2000-23-52](https://openairdocs.org/ad/2000-23-52) (historical): Main Rotor Shaft Assembly · Sikorsky S-76A Model/Series (all), S-76B and S-76C. Effective Feb 16, 2001
- [AD 2000-23-51](https://openairdocs.org/ad/2000-23-51) (historical): Main Transmission Oil Seal · Sikorsky S-76A Model/Series (all), S-76B and S-76C

## Information bulletins (advisory) (2)

- [SAIB AIR-20-11](https://openairdocs.org/saib/AIR-20-11): Attitude and Direction Data System, Incorrect AHRS Yaw Rate Output. Issued Jun 22, 2020
- [SAIB SW-08-37](https://openairdocs.org/saib/SW-08-37): Inoperative Cyclic Control Stick Guard. Issued Jul 22, 2008

## Registered aircraft (23)

- [N152AE](https://openairdocs.org/aircraft/N152AE): [Mustang Leasing LLC](https://openairdocs.org/faa-owner/MUSTANG%20LEASING%20LLC), [Henderson, NV](https://openairdocs.org/faa-place/NV/Henderson), built 2008, S/N 760714
- [N176FX](https://openairdocs.org/aircraft/N176FX): [Flexjet Vertical Lift LLC](https://openairdocs.org/faa-owner/FLEXJET%20VERTICAL%20LIFT%20LLC), [Stratford, CT](https://openairdocs.org/faa-place/CT/Stratford), built 2007, S/N 760646
- [N2119A](https://openairdocs.org/aircraft/N2119A): [Arrow Aviation Co LLC](https://openairdocs.org/faa-owner/ARROW%20AVIATION%20CO%20LLC), [Broussard, LA](https://openairdocs.org/faa-place/LA/Broussard), S/N 760640
- [N2133X](https://openairdocs.org/aircraft/N2133X): [Arrow Aviation Co LLC](https://openairdocs.org/faa-owner/ARROW%20AVIATION%20CO%20LLC), [Broussard, LA](https://openairdocs.org/faa-place/LA/Broussard), S/N 760638
- [N278FX](https://openairdocs.org/aircraft/N278FX): [Flexjet Vertical Lift LLC](https://openairdocs.org/faa-owner/FLEXJET%20VERTICAL%20LIFT%20LLC), [Stratford, CT](https://openairdocs.org/faa-place/CT/Stratford), built 2008, S/N 760750
- [N35HF](https://openairdocs.org/aircraft/N35HF): [Heliflite Shares LLC](https://openairdocs.org/faa-owner/HELIFLITE%20SHARES%20LLC), [Kearny, NJ](https://openairdocs.org/faa-place/NJ/Kearny), built 2008, S/N 760746
- [N36HF](https://openairdocs.org/aircraft/N36HF): [Heliflite Shares LLC](https://openairdocs.org/faa-owner/HELIFLITE%20SHARES%20LLC), [Kearny, NJ](https://openairdocs.org/faa-place/NJ/Kearny), built 2009, S/N 760776
- [N376WH](https://openairdocs.org/aircraft/N376WH): [Gm Leasing Company LLC](https://openairdocs.org/faa-owner/GM%20LEASING%20COMPANY%20LLC), [Broussard, LA](https://openairdocs.org/faa-place/LA/Broussard), built 2009, S/N 760759
- [N40WH](https://openairdocs.org/aircraft/N40WH): [Gm Leasing Co LLC](https://openairdocs.org/faa-owner/GM%20LEASING%20CO%20LLC), [Broussard, LA](https://openairdocs.org/faa-place/LA/Broussard), built 2009, S/N 760756
- [N454WH](https://openairdocs.org/aircraft/N454WH): [Gm Leasing Company LLC](https://openairdocs.org/faa-owner/GM%20LEASING%20COMPANY%20LLC), [Broussard, LA](https://openairdocs.org/faa-place/LA/Broussard), built 2010, S/N 760802
- [N614JC](https://openairdocs.org/aircraft/N614JC): [Knight Helo LLC](https://openairdocs.org/faa-owner/KNIGHT%20HELO%20LLC), [Wilmington, DE](https://openairdocs.org/faa-place/DE/Wilmington), S/N 760694
- [N718P](https://openairdocs.org/aircraft/N718P): [Phi Aviation LLC](https://openairdocs.org/faa-owner/PHI%20AVIATION%20LLC), [Lafayette, LA](https://openairdocs.org/faa-place/LA/Lafayette), built 2007, S/N 760686
- [N753P](https://openairdocs.org/aircraft/N753P): [Phi Health LLC](https://openairdocs.org/faa-owner/PHI%20HEALTH%20LLC), [Tempe, AZ](https://openairdocs.org/faa-place/AZ/Tempe), built 2008, S/N 760726
- [N754L](https://openairdocs.org/aircraft/N754L): [Arrow Aviation Co LLC](https://openairdocs.org/faa-owner/ARROW%20AVIATION%20CO%20LLC), [Broussard, LA](https://openairdocs.org/faa-place/LA/Broussard), S/N 760754
- [N759P](https://openairdocs.org/aircraft/N759P): [Phi Health LLC](https://openairdocs.org/faa-owner/PHI%20HEALTH%20LLC), [Tempe, AZ](https://openairdocs.org/faa-place/AZ/Tempe), built 2007, S/N 760690
- [N764AM](https://openairdocs.org/aircraft/N764AM): [North Flight Aero Med](https://openairdocs.org/faa-owner/NORTH%20FLIGHT%20AERO%20MED), [Grand Rapids, MI](https://openairdocs.org/faa-place/MI/Grand%20Rapids), built 2009, S/N 760764
- [N76ZA](https://openairdocs.org/aircraft/N76ZA): [N76za LLC](https://openairdocs.org/faa-owner/N76ZA%20LLC), [New York, NY](https://openairdocs.org/faa-place/NY/New%20York), built 2007, S/N 760653
- [N773BG](https://openairdocs.org/aircraft/N773BG): [Bristow LLC](https://openairdocs.org/faa-owner/BRISTOW%20LLC), [Lake Charles, LA](https://openairdocs.org/faa-place/LA/Lake%20Charles), built 2009, S/N 760773
- [N785P](https://openairdocs.org/aircraft/N785P): [Robert, LA](https://openairdocs.org/faa-place/LA/Robert), built 2006, S/N 760635, Sale reported, canceled
- [N787RL](https://openairdocs.org/aircraft/N787RL): [Gm Leasing Company LLC](https://openairdocs.org/faa-owner/GM%20LEASING%20COMPANY%20LLC), [Broussard, LA](https://openairdocs.org/faa-place/LA/Broussard), built 2009, S/N 760778
- [N794P](https://openairdocs.org/aircraft/N794P): [Phi Aviation LLC](https://openairdocs.org/faa-owner/PHI%20AVIATION%20LLC), [Lafayette, LA](https://openairdocs.org/faa-place/LA/Lafayette), built 2008, S/N 760737
- [N893BG](https://openairdocs.org/aircraft/N893BG): [Bristow U S LLC](https://openairdocs.org/faa-owner/BRISTOW%20U%20S%20LLC), [New Iberia, LA](https://openairdocs.org/faa-place/LA/New%20Iberia), built 2009, S/N 760804
- [N896BG](https://openairdocs.org/aircraft/N896BG): [Bristow U.S. LLC](https://openairdocs.org/faa-owner/BRISTOW%20U.S.%20LLC), [New Iberia, LA](https://openairdocs.org/faa-place/LA/New%20Iberia), S/N 760777

## NTSB investigations

None matched to aircraft with this model.

## FAA accident and incident reports (1)

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [Incident 20241113016729I](https://openairdocs.org/incident/20241113016729I), Nov 13, 2024: Keystone Helicopter Corp S-76C (N787RL), Galliano, LA, Minor damage. A video of the incident showed the helicopter in a hover, with all three-landing gear down, before landing on the helipad at the south lafourche airport…

## Service difficulty reports (717, newest 50)

As reported by operators and repair stations, by the model named in the report.

- [SDR 2026FA0000301](https://openairdocs.org/sdr/2026FA0000301), Apr 24, 2026: INDICATION SYS. FALSE INDICATION. RDAU DISPLAYS FAULTY FUEL INDICATIONS. AFTER START-UP #1 FUEL QUANTITY DROPS APPROX. 100 LBS. THEN RISES THE SAME AFTER SHUTDOWN.
- [SDR HEEA202601020001](https://openairdocs.org/sdr/HEEA202601020001), Jan 1, 2026: BRACE. INOPERATIVE. ON CLIMB OUT FROM KGLS, RIGHT SIDE LANDING GEAR WOULD NOT RETRACT.
- [SDR HEEA202509050001](https://openairdocs.org/sdr/HEEA202509050001), Sep 3, 2025: TRANSDUCER. INOPERATIVE. NUMBER ONE ENGINE BARRIER FILTER MAINTENANCE CAUTION CAME ON IN FLIGHT RETURNED TO HOUMA. ALL OTHER ENGINE INDICATIONS NORMAL.
- [SDR HEEA202507240001](https://openairdocs.org/sdr/HEEA202507240001), Jul 21, 2025: VALVE. LEAKING. DURING CRUISE FLIGHT, SLOW STEADY DECREASE OF NUMBER 1 ENGINE OIL PSI WAS NOTED.
- [SDR VE7A202505190127](https://openairdocs.org/sdr/VE7A202505190127), May 14, 2025: FIRE DETECTOR. FAILED. #2 ENGINE FIRE CAUTION LIGHT ILLUMINATED AND ALARM SOUND WAS PRESENT DURING FLIGHT.
- [SDR 2025F00046](https://openairdocs.org/sdr/2025F00046), Feb 19, 2025: COMPUTER. FAILED. PILOTS IIDS SCREEN FAILS AT STARTUP. CENTER IIDS SCREEN FAILS INTERMITTENTLY DURING FLIGHT.
- [SDR HEEA202412180001](https://openairdocs.org/sdr/HEEA202412180001), Dec 17, 2024: STARTER GEN. INOPERATIVE. #2 GENERATOR FAILED DURING OUR HIGH ORBIT OF MC773. CONTINUED ORBITING AND FOLLOWED THE EMERGENCY PROCEDURE CHECKLIST. UNABLE TO RESET. LANDED AT MC773 WITHOUT 
- [SDR YTRA2024111500288](https://openairdocs.org/sdr/YTRA2024111500288), Nov 15, 2024: FITTING. CRACKED. LEFT MAIN LANDING GEAR COLLAPSED ONCE AIRCRAFT SETTLED. GEAR WAS DOWN AND LOCKED. FOUND AIRFRAME FITTING CRACKED.
- [SDR YTRA20241127001](https://openairdocs.org/sdr/YTRA20241127001), Nov 13, 2024: FITTING. CRACKED. LEFT MAIN LANDING GEAR COLLAPSED WHEN AIRCRAFT SETTLED. GEAR WAS DOWN AND LOCKED. FOUND AIRFRAME FITTING CRACKED.
- [SDR VE7A2024091700001](https://openairdocs.org/sdr/VE7A2024091700001), Sep 14, 2024: PUMP. FAILED. ON CLIMB OUT WHEN AC WAS TURNED ON ODOR FILLED THE COCKPIT AREA. FLIGHT CANCELED AND RETURNED TO BASE. AIR PUMP MFG BY IMPACT INSTRUMENTATION FAILED AND CAUSED 
- [SDR YTRA2024091626001](https://openairdocs.org/sdr/YTRA2024091626001), Sep 13, 2024: FIRE DETECTOR. INTERMITTENT. #2 ENGINE FIRE LIGHT ILLUMINATED INTERMITTENTLY IN LANDING PHASE OF FLIGHT. REMOVED AND REPLACED #2 REAR FLAME DETECTOR.
- [SDR HEEA202409160001](https://openairdocs.org/sdr/HEEA202409160001), Sep 13, 2024: TRANSDUCER. INOPERATIVE. DURING 3Q CLIMB OUT, FLUCTUATIONS IN TORQUE AND N1 OBSERVED WITH YAW TO THE LEFT. THIS WAS FOLLOWED BY DECU MINOR FAULT. PROCEEDED TO RTB.
- [SDR HEEA202407290001](https://openairdocs.org/sdr/HEEA202407290001), Jul 26, 2024: TRANSMITTER. INOPERATIVE. DURING CRUISE FLIGHT THE MGB PRESSURE INDICATION BEGAN TO FLUCTUATE BETWEEN 65PSI TO 0 PSI. AIRCRAFT RETURNED TO BASE.
- [SDR HEEA202407240001](https://openairdocs.org/sdr/HEEA202407240001), Jul 23, 2024: MOTOR. INOPERATIVE. 15 MINUTES FROM HOUMA, SMOKE WAS OBSERVED COMING OUT OF A/C VENTS. AIR CONDITIONER AND FAN WERE TURNED OFF AND SMOKE IMMEDIATELY STOPPED.
- [SDR HEEA202405230001](https://openairdocs.org/sdr/HEEA202405230001), May 21, 2024: HYDRAULIC SYSTEM. FLUCTUATES. #1 HYDRAULIC FLUCTUATION, RTB
- [SDR HEEA202405210001](https://openairdocs.org/sdr/HEEA202405210001), May 14, 2024: UNKNOWN. SMOKE. DURING CRUISE FLIGHT, EXPERIENCED SMOKE IN COCKPIT FOLLOWED BY ELECTRICAL BURNING SMELL. OPENED DOOR WINDOWS AND TURNED OFF AC AND BLOWER. MC365 WAS WITHIN A MI
- [SDR HEEA202402280001](https://openairdocs.org/sdr/HEEA202402280001), Feb 26, 2024: COMPUTER. FAILED. DURING APPROACH OFFSHORE, #2 AP FAILED.
- [SDR VE7A202402069052](https://openairdocs.org/sdr/VE7A202402069052), Feb 2, 2024: FIRE DETECTOR. FALSE INDICATION. : DURING CRUISE FLIGHT #1 ENG FIRE LIGHT, ALONG WITH AUDIO FLASHED ON FOR ABOUT ONE SECOND. NO SECONDARY INDICATIONS OF FIRE OBSERVED. ELECTED TO ABORT FLIGHT. 
- [SDR HEEA202401310001](https://openairdocs.org/sdr/HEEA202401310001), Jan 30, 2024: TRANSMISSION. MAKING METAL. MAIN GEAR BOX CHIP LIGHT CAME ON. ALL OTHER INDICATIONS WERE NORMAL, RESET CIRCUIT BREAKER, AND LIGHT REMAINED ON. AIRCRAFT RETURNED TO HOUMA.
- [SDR HEEA202401110001](https://openairdocs.org/sdr/HEEA202401110001), Jan 11, 2024: PRESSURE SWITCH. INOPERATIVE. # SERVO SYSTEM LIGHT ILLUMINATED IN CRUISE FLIGHT. FOLLOWED EMERGENCY PROCEDURE CHECK LIST. HYDRAULIC PRESSURE REMAINED IN GREEN. NO BINDING IN CONTROL. SLOWED 
- [SDR U0GA202311150001](https://openairdocs.org/sdr/U0GA202311150001), Nov 13, 2023: CONTROL ROD. DAMAGED. BRISTOW RECENTLY DISCOVERED A LOOSE JAM NUT ON AFT M/R SERVO INPUT ROD END DURING A SCHEDULED INSPECTION. THE JAM NUT IS THE SUBJECT OF FAA AD 2015-19-51, AD 20
- [SDR HEEA202310310001](https://openairdocs.org/sdr/HEEA202310310001), Oct 31, 2023: GAUGE. FAILED. DURING CRUISE FLIGHT THE FUEL QUANTITY GAUGE FAILED EN-ROUTE TO MC773. THE CREW ELECTED TO DIVERT TO THEIR OFFSHORE ALTERNATE TO BE EVALUATED BY MECHANIC.
- [SDR HEEA202310230001](https://openairdocs.org/sdr/HEEA202310230001), Oct 23, 2023: RETAINING RING. DISLODGED. DURING CRUISE FLIGHT, WASHERS AND RETENTION RING WERE SEEN ON THE COPILOT FLOOR. DISCOVERED THE RIGHT TAIL ROTOR PEDAL WAS SLIPPING OFF. RETURNED TO BASE WITH N
- [SDR HEEA202310170002](https://openairdocs.org/sdr/HEEA202310170002), Oct 17, 2023: LANDING GEAR. INOPERATIVE. RTB DUE TO NOSE LANDING GEAR DID NOT RETRACT.
- [SDR U0GA ASR11041](https://openairdocs.org/sdr/U0GA%20ASR11041), Aug 27, 2023: UNKNOWN. UNKNOWN. HOLDING SOUTH OF 92LA AT 500' AGL FOR COMPANY TO CLEAR HOSPITAL HELIPAD, #2 ENGINE FIRE WARNING TONE SOUNDED, #2 ENGINE FIRE LIGHT ILLUMINATED, MASTER CAUTION L
- [SDR 2023FA0000392](https://openairdocs.org/sdr/2023FA0000392), Jul 26, 2023: TRANSDUCER. ABNORMAL. MOMENTARY ENGINE ROLL BACK WITH TORQUE SPLIT AND YAWING MOTION
- [SDR 2023FA0000387](https://openairdocs.org/sdr/2023FA0000387), Jul 26, 2023: TRANSDUCER. ABNORMAL. MOMENTARY PARTIAL POWER LOSS WITH YAW KICK AND LOSS OF TORQUE
- [SDR 2023FA0000391](https://openairdocs.org/sdr/2023FA0000391), Jul 14, 2023: TRANSDUCER. ABNORMAL. MOMENTARY ENGINE ROLL BACK WITH TORQUE SPLIT AND YAWING MOTION
- [SDR 2023FA0000386](https://openairdocs.org/sdr/2023FA0000386), Jun 13, 2023: TRANSDUCER. ABNORMAL. MOMENTARY PARTIAL POWER LOSS WITH YAW KICK AND LOSS OF TORQUE
- [SDR 2023FA0000390](https://openairdocs.org/sdr/2023FA0000390), Jun 5, 2023: TRANSDUCER. ABNORMAL. MOMENTARY ENGINE ROLL BACK WITH TORQUE SPLIT AND YAWING MOTION
- [SDR 2023FA0000389](https://openairdocs.org/sdr/2023FA0000389), May 2, 2023: TRANSDUCER. ABNORMAL. MOMENTARY ENGINE ROLL BACK WITH TORQUE SPLIT AND YAWING MOTION.
- [SDR 2023FA0000385](https://openairdocs.org/sdr/2023FA0000385), Apr 20, 2023: TRANSDUCER. ABNORMAL. MOMENTARY PARTIAL POWER LOSS WITH YAW KICK AND LOSS OF TORQUE
- [SDR 2023FA0000213](https://openairdocs.org/sdr/2023FA0000213), Apr 13, 2023: TRANSDUCER. DEFECTIVE. PILOT REPORT: WHEN DEPARTING PN44 IN 431MK WITH TWO PAX ONBOARD, WE EXPERIENCED A MOMENTARY LOSS OF POWER WITH ENGINE OSCILLATIONS. ON TAKEOFF WE PULLED APPROXI
- [SDR 2023FA0000384](https://openairdocs.org/sdr/2023FA0000384), Mar 23, 2023: TRANSDUCER. ABNORMAL. MOMENTARY PARTIAL POWER LOSS WITH YAW KICK AND LOSS OF TORQUE
- [SDR 2023FA0000388](https://openairdocs.org/sdr/2023FA0000388), Mar 16, 2023: TRANSDUCER. ABNORMAL. ENGINE OUT INDICATION WITH A TORQUE SPLIT AND YAWING MOTION MOMENTARILY
- [SDR 2023F00074](https://openairdocs.org/sdr/2023F00074), Mar 3, 2023: CABLE. INOPERATIVE. DURING INITIAL LANDING CHECK, THE GEAR LEVER WAS MOVE TO THE LOWERED POSITION. THE NOSE GEAR LIGHT WOULD NOT ILLUMINATE AND WAS INDICATING UNLOCKED. CREW VERIFI
- [SDR 2023FA0000383](https://openairdocs.org/sdr/2023FA0000383), Mar 1, 2023: TRANSDUCER. ABNORMAL. MOMENTARY PARTIAL POWER LOSS WITH YAW KICK AND LOSS OF TORQUE
- [SDR 2023FA0000085](https://openairdocs.org/sdr/2023FA0000085), Feb 10, 2023: CONTACTOR. INOPERATIVE. DURING CRUISE IN IMC NO 2 DC GENERATOR FAILED AND DID NOT RESET AFTER EMERGENCY PROCEDURE WAS PERFORMED.
- [SDR YTRA22249](https://openairdocs.org/sdr/YTRA22249), Sep 2, 2022: FIRE DETECTOR. DEFECTIVE. AT APPROXIMATELY 10:30 AM ENROUTE FROM MC109 TO GALLIANO WHILE CRUISING AT 2200 FT AND ABOUT 45 MILES FROM THE BASE THE #1 ENGINE FIRE LIGHT ILLUMINATED WITH TH
- [SDR YTRA22244](https://openairdocs.org/sdr/YTRA22244), Sep 1, 2022: SMOKE DETECTOR. SMOKE. "AFT BAGGAGE" CAUTION LIGHT ILLUMINATED DURING DEPARTURE CLIMB OUT. ON LANDING THE SIC INSPECTED THE BAGGAGE COMPARTMENT AND NOTED SMOKE COMING OUT. THE PIC AND
- [SDR YTRA2218101](https://openairdocs.org/sdr/YTRA2218101), Jun 30, 2022: CONNECTOR. BURNED. DURING THE FIRST ENGINE CHECK, SMOKE WAS DETECTED IN THE CABIN SO WE ABORTED THE CHECK SHUTDOWN THE ENGINES DOWN AND EVACUATED THE AIRCRAFT.
- [SDR 2023FA0000583](https://openairdocs.org/sdr/2023FA0000583), Jun 27, 2022: KEELBEAM. CORRODED. BONDED ASSY. KEEL BEAM PANEL CORRODED BEYOND LIMITS. REPLACED CORRODED KEEL BEAM WITH SERVICEABLE KEEL BEAM.
- [SDR 2022FA0000220](https://openairdocs.org/sdr/2022FA0000220), Apr 19, 2022: NONE. LEAKING. ON CLIMB OUT FROM ARA THERE WAS A STRONG SMELL OF FUEL. ALL CREW MEMBERS SMELLED IT. RTB AND SHUT DOWN.
- [SDR 2023FA0000382](https://openairdocs.org/sdr/2023FA0000382), Mar 24, 2022: TRANSDUCER. ABNORMAL. AIRCRAFT HAS A MOMENTARY POWER LOSS WITH ENGINE OUT INDICATION AND TORQUE SPLIT WITH A YAWING MOTION,
- [SDR 2023FA0000381](https://openairdocs.org/sdr/2023FA0000381), Mar 24, 2022: TRANSDUCER. ABNORMAL. INFLIGHT MOMENTARY ENGINE ROLLBACK WITH YAW KICK AND TORQUE LOSS
- [SDR 2022FA0000632](https://openairdocs.org/sdr/2022FA0000632), Feb 6, 2022: FIRE WARNING. FALSE INDICATION. FALSE FIRE WARNING DURING FIGHT
- [SDR ALGA2020073103002](https://openairdocs.org/sdr/ALGA2020073103002), Jul 28, 2020: PUMP. FAILED. AFTER TAKEOFF, IN CRUISE, THE NR 1 HYDRAULICS INDICATOR DROPPED TO ZERO AND THE NR 1 SERVO LIGHT IN THE CAUTION ADVISORY PANEL ILLUMINATED BY SLIGHT FEED BACK I
- [SDR HEER202001023483](https://openairdocs.org/sdr/HEER202001023483), Dec 23, 2019: WIRE. BURNED. SMOKE IN CABIN. FOUND WIRE ON MOTOR BURNT/CHAFED. REPLACED A/C BLOWER ASSEMBLY.
- [SDR ALGA20191205154](https://openairdocs.org/sdr/ALGA20191205154), Dec 3, 2019: DUCT. CRACKED. THE CABIN HEATER WAS ON AND AS USUAL SMALL AMOUNT OF SMOKE & ENGINE CLEANER ODOR IS PRESENT WHEN HEATER IS INITIALLY TURNED ON. CREW INFORMED PASSENGERS THAT TH
- [SDR ALGA020190828087](https://openairdocs.org/sdr/ALGA020190828087), Aug 24, 2019: MAGNETIC SEAL. LEAKING. OIL PRESSURE ON #2 ENGINE FLUCTUATING BETWEEN 30-45PSI , OIL TEMP BEGAN TO DECREASE FROM 74 DEG C - 67 DEG C . OIL PRESSURE LIGHT ILLUMINATED . ENGINE WAS SECUR

All 717: https://openairdocs.org/model/keystone-helicopter-s-76c/reports.md

## STCs that may be installed (OpenAirDocs) (352, first 50)

Approved for this model: the STC's model list names it on its data sheet, or a series that includes it. In force first, then newest. The registry doesn't record which STCs an aircraft has.

- [STC SR12301IB](https://openairdocs.org/stc/SR12301IB): Installation of Nginuity DAQ9000 as an alternate Flight Data Acquisition Unit (FDAU). 365 AEROSPACE DDS LIMITED
- [STC SR04465NY](https://openairdocs.org/stc/SR04465NY): Installation of the iPad Mount. Avio Design Group Inc
- [STC SR02727SE](https://openairdocs.org/stc/SR02727SE): Installation and maintenance of the Sunspot 36 and 46 series lights. Whelen Aerospace Technologies
- [STC SR12106IB](https://openairdocs.org/stc/SR12106IB): Installation of Upgrade of Radar Altimeter for 5G Resiliency. Maxcraft Avionics Ltd
- [STC SR268CH](https://openairdocs.org/stc/SR268CH): Installation of BFG FlightSystems TCAS I (Model TCAS-791/A). Acron Aviation Inc
- [STC SR01955SE](https://openairdocs.org/stc/SR01955SE): Installation of a Supplemental Lighting System. Aviation Specialties Unlimited Inc
- [STC SR02473AK](https://openairdocs.org/stc/SR02473AK): Installation of the L-3 Communications NGT-9000R/RD and NGT-9000/D ADS-B IN/OUT system. StandardAero Atlantic USA Inc
- [STC SR09011RC](https://openairdocs.org/stc/SR09011RC): Manufacture of an emergency exit window in passenger door. HELIFAB
- [STC SR09211RC](https://openairdocs.org/stc/SR09211RC): Installation of an external mount life raft deployment system. HELIFAB
- [STC SR09355RC](https://openairdocs.org/stc/SR09355RC): Installation of 12 place passenger seats. HELIFAB
- [STC SR01367SE](https://openairdocs.org/stc/SR01367SE): Installation of Rockwell Collins Four Tube FDS 2000 Electronic Flight Instrument System (EFIS) and Rockwell Collins AHC 3000 Attitude Heading Reference System (AHRS). Helifab
- [STC SH3319NM](https://openairdocs.org/stc/SH3319NM): Installation of Precise Flight Pulselite Control Unit in the Landing /Taxi Recognition Visual Control Light system,. Precise Flight Inc
- [STC SR00112BO](https://openairdocs.org/stc/SR00112BO): Installation of either the OuterLink Corporation CP-2 or CP-3i SATCOM System in accordance with OuterLink Corporation Master Document List No. D000-0042, Revision N, dated August 19, 2009, or later FAA-approved revision. Outerlink Corporation
- [STC SR01520SE](https://openairdocs.org/stc/SR01520SE): Installation of a Modularized Main DC Electrical Junction Box. Helifab
- [STC SR04609NY](https://openairdocs.org/stc/SR04609NY): Installation of Garmin HTAWS (Helicopter Terrain Awareness Warning System). Maxcraft Avionics Ltd
- [STC SR02322AK](https://openairdocs.org/stc/SR02322AK): Installation of a fixed mounted Max-Vis Enhanced Vision System (EVS) Model 1500. PECO Inc
- [STC SR00925DE](https://openairdocs.org/stc/SR00925DE): Installation of Garmin GTX 335/335R and GTX345/345R transponders to provide ADS-B Out and In functionality. Peregrine
- [STC SR04440NY](https://openairdocs.org/stc/SR04440NY): Installation of the Mid Continent MD302 Standby Attitude Module. Maxcraft Avionics Ltd
- [STC SR02667SE](https://openairdocs.org/stc/SR02667SE): Installation of a Honeywell ASPIRE 200 Intermediate Gain (IG) SATCOM system. Honeywell International
- [STC SR00764DE](https://openairdocs.org/stc/SR00764DE): Installation of Automatic Dependent Surveillance - Broadcast (ADS-B) Out functionality using the Trig Avionics TT22 Transponder and Freeflight Systems 1201 Global Positioning System (GPS) with Wide Area Augmentation System (WAAS). Peregrine
- [STC SH5778SW](https://openairdocs.org/stc/SH5778SW): Addition of Electrically Driven Vapor Cycle, Freon or Refrigerant R-134a, Air Conditioning System. Air Comm Corporation
- [STC SR00391DE](https://openairdocs.org/stc/SR00391DE): Installation of TREC dual patient handling system. LifePort LLC
- [STC SR02125LA](https://openairdocs.org/stc/SR02125LA): Installation of a One Man Loading Patient Litter System. LifePort LLC
- [STC SR02611NY-D](https://openairdocs.org/stc/SR02611NY-D): Installation of the LifePort One Man Loading Patient Litter System. LifePort LLC
- [STC SH8678SW](https://openairdocs.org/stc/SH8678SW): Installation of an electronic bay access door window. The NORDAM Group LLC
- [STC SH8679SW](https://openairdocs.org/stc/SH8679SW): Installation of a chin window. The NORDAM Group LLC
- [STC SR04023CH](https://openairdocs.org/stc/SR04023CH): Install air ambulance conversion. Spectrum Aeromed LLC dba Spectrum Aeromed
- [STC SR00847DE](https://openairdocs.org/stc/SR00847DE): Replacement of Honeywell (formerly Sperry) ED-800 cathode ray tube (CRT) display, part number (p/n) 7003110-901/-902, with Esterline CMC Electronics CMA-6800 multi-purpose liquid crystal display (LCD), p/n 100-604045-001/-002, respectively. Peregrine
- [STC SR03551NY](https://openairdocs.org/stc/SR03551NY): Installation of Garmin GTX33H Mode S Transponder and GTS Traffic System. Maxcraft Avionics Ltd
- [STC SR03573NY](https://openairdocs.org/stc/SR03573NY): Installation of Garmin GTN/GNS() Navigation with EDZ-705 or EDZ-756 EFIS. Maxcraft Avionics Ltd
- [STC SR04227NY](https://openairdocs.org/stc/SR04227NY): Installation of Garmin GWX Weather Radar System. Maxcraft Avionics Ltd
- [STC SR00256BO](https://openairdocs.org/stc/SR00256BO): Installation of Universal Avionics Systems Corporation (UASC) Software Control Number (SCN) 31.X in UASC Cockpit Display Computer (UCDC) P/N 3040-05-( ). Pro Star Aviation, LLC
- [STC SR00264BO](https://openairdocs.org/stc/SR00264BO): Installation of Garmin GMX 200 Multi Function Display. Pro Star Aviation, LLC
- [STC SR00274BO](https://openairdocs.org/stc/SR00274BO): Installation of an L3 Communications GH-3100 Electronic Standby Instrument System (ESIS) and Optional Emergency Bus. Pro Star Aviation, LLC
- [STC SR00275BO](https://openairdocs.org/stc/SR00275BO): Installation of tail shaft cover antenna mount. Pro Star Aviation, LLC
- [STC SR00287BO](https://openairdocs.org/stc/SR00287BO): Installation of a single UNS-1Fw/Lw Flight Management System (FMS) with embedded Wide Area Augmentation System and a Universal LP/LPV Monitor in accordance with ProStar Installation Data List (IDL) No. 20819-IDL-01, Revision E, dated 4 Feburary 2011, or later FAA-approved revisions. Pro Star Aviation, LLC
- [STC SR00289BO](https://openairdocs.org/stc/SR00289BO): Installation ofa Kollsman General Aviation Vision System (GAViS ). Pro Star Aviation, LLC
- [STC SR04022NY](https://openairdocs.org/stc/SR04022NY): AF-ADELT improved installation. Caledonian Airborne Systems Ltd Caledonian House
- [STC SR02445NY-D](https://openairdocs.org/stc/SR02445NY-D): Installation of a Canadian Marconi (CMC) CMA-2012C in place of a RACAL 91 Doppler. RSG Products
- [STC SR01616SE](https://openairdocs.org/stc/SR01616SE): Installation of an engine air filter system. Aerometals
- [STC SR00763DE](https://openairdocs.org/stc/SR00763DE): Installation of a 62 Gallon Auxiliary Fuel Tank in the baggage compartment. Helifab Inc
- [STC SR09577RC](https://openairdocs.org/stc/SR09577RC): Installation of an Automatic Deployable Emergency Locator Transmitter (ADELT) System. Bristow US LLC
- [STC SR02455AK](https://openairdocs.org/stc/SR02455AK): Installation of a Honeywell Enhanced Ground Proximity Warning System (EGPWS). Vector Aerospace Helicopter Services USA Inc
- [STC SR02458AK](https://openairdocs.org/stc/SR02458AK): Installation of an LSI Helicopter Emergency Egress Lighting (HEEL) System. Vector Aerospace Helicopter Services USA Inc
- [STC SR02459AK](https://openairdocs.org/stc/SR02459AK): Installation of a Honeywell Multifunction Radar Display (MFRD). Vector Aerospace Helicopter Services USA Inc
- [STC SR02460AK](https://openairdocs.org/stc/SR02460AK): Installation of a Sagem Auxiliary Flight Data Acquisition & Management Unit (AFDAMU) & Fairchild Cockpit Voice & Data Recorder (CVDR) system. Vector Aerospace Helicopter Services USA Inc
- [STC SR02461AK](https://openairdocs.org/stc/SR02461AK): Installation of a Bendix/King KTA 970 TCAS 1 traffic collision avoidance system. Vector Aerospace Helicopter Services USA Inc
- [STC SR02462AK](https://openairdocs.org/stc/SR02462AK): Installation of a Garmin GPS 400 system. Vector Aerospace Helicopter Services USA Inc
- [STC SR02456AK](https://openairdocs.org/stc/SR02456AK): Installation of a D1000C Iridium Satcom Blue Sky System. Vector Aerospace Helicopter Services USA Inc
- [STC SR02457AK](https://openairdocs.org/stc/SR02457AK): Installation of an ACH1000 Advanced Control System Head for an Iridium Satcom Blue Sky System. Vector Aerospace Helicopter Services USA Inc

All 352: https://openairdocs.org/model/keystone-helicopter-s-76c/stcs.md

## The same model under other registry codes

Amateur-built copies and renamed makers get their own codes.

- [Sikorsky S-76C](https://openairdocs.org/model/sikorsky-s-76c): 78 registered aircraft, registry code 8143008

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