# Twin Commander 690C

- Type: Aircraft model (FAA registry)
- Registry code: 3970504
- Manufacturer (registry): TWIN COMMANDER AIRCRAFT CORP
- Model: 690C
- Aircraft type: Fixed wing multi engine
- Category: Airplane
- Engines: 2 · Turbo-prop
- Seats: 11
- Weight class: Up to 12,499 lb
- Certification: Type certificated
- Data sheet: [TCDS 2A4](https://openairdocs.org/tcds/2A4) (OpenAirDocs)
- Holder: Twin Commander Aircraft LLC
- Registered aircraft: 2
- Page: https://openairdocs.org/model/twin-commander-690c

Model codes come from the FAA registry's reference file. ADs are matched to them by model name and maker.

## 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 2005-18-20](https://openairdocs.org/ad/2005-18-20): "FASTprop" propeller de-icers · Hartzell PHC-C3YF-1RF/F8468A(B,K)-8R constant speed propeller (STC SA00718LA or 17 others). Effective Oct 14, 2005
- [AD 2005-01-19](https://openairdocs.org/ad/2005-01-19): Mode S transponders · GARMIN International GTX 330D, GTX 330, GTX 33D and 830 more. Effective Feb 23, 2005
- [AD 2000-02-30](https://openairdocs.org/ad/2000-02-30): Airframe Pneumatic Deicing Boots · Twin Commander 680, 680-E, 680-F and 15 more. Effective Mar 24, 2000
- [AD 98-08-25 R1](https://openairdocs.org/ad/98-08-25-R1): Nose Landing Gear (NLG) Drag Link Bolt · Twin Commander 500-S, 500-U, 680-F and 9 more. Effective Jan 5, 1999
- [AD 98-20-34](https://openairdocs.org/ad/98-20-34): Airplane Flight Manuals--Severe Icing Conditions · Twin Commander 500, 500-A, 500-B and 24 more. Effective Nov 3, 1998
- [AD 98-14-03](https://openairdocs.org/ad/98-14-03): Transponders · Cessna 172, 172A, 172B and 230 more. Effective Aug 16, 1998
- [AD 98-07-17](https://openairdocs.org/ad/98-07-17): Flap System · Twin Commander 500, 500-A, 500-B and 27 more. Effective May 29, 1998
- [AD 98-08-19](https://openairdocs.org/ad/98-08-19): Wing to Fuselage Attachment Brackets and Straps · Twin Commander 500, 500-A, 500-B and 27 more. Effective May 18, 1998
- [AD 95-19-18](https://openairdocs.org/ad/95-19-18): Turbulent Air Penetration and Maneuvering Speeds · Twin Commander 680-T, 680-V, 680-W and 9 more. Effective Oct 25, 1995
- [AD 95-12-23](https://openairdocs.org/ad/95-12-23): Wing Structure · Twin Commander 690C and 695. Effective Jul 30, 1995
- [AD 95-13-02](https://openairdocs.org/ad/95-13-02): Twin Commander 685, 690, 690A and 5 more. Effective Jul 22, 1995
- [AD 87-24-07 R1](https://openairdocs.org/ad/87-24-07-R1): POH/AFM Revision - Icing · Twin Commander 690, 690A, 690B and 5 more. Effective Feb 9, 1988
- [AD 84-19-05](https://openairdocs.org/ad/84-19-05): Engine Mount Systems · Twin Commander 690, 690A, 690B and 4 more. Effective Oct 8, 1984
- [AD 79-07-02](https://openairdocs.org/ad/79-07-02): Batteries · Aircraft Parts & Development A, A-2, A-3 and 149 more. Effective Apr 3, 1979
- [AD 78-05-06](https://openairdocs.org/ad/78-05-06): Flexible Fuel Cells · Cessna 180, 182, 185 and 98 more. Effective Jun 30, 1978

Historical (superseded or no longer in force):

- [AD 98-08-25](https://openairdocs.org/ad/98-08-25) (historical): Nose Landing Gear (NLG) Drag Link Bolt · Twin Commander 500-S, 500-U, 680-F and 9 more. Effective May 18, 1998
- [AD 96-12-08](https://openairdocs.org/ad/96-12-08) (historical): Nose Landing Gear (NLG) Drag Link Bolt · Twin Commander 500-S, 500-U, 680-F and 8 more. Effective Jun 27, 1996
- [AD 94-04-17](https://openairdocs.org/ad/94-04-17) (historical): Flap System Cable · Twin Commander 500, 500-A, 500-B and 27 more. Effective Apr 15, 1994

## Information bulletins (advisory) (1)

- [SAIB 2023-14](https://openairdocs.org/saib/2023-14): Landing Gear Retract/Extend System. Issued Nov 14, 2023

## Registered aircraft (2)

- [N57TB](https://openairdocs.org/aircraft/N57TB): [International Air Services Inc Trustee](https://openairdocs.org/faa-owner/INTERNATIONAL%20AIR%20SERVICES%20INC%20TRUSTEE), [Carson City, NV](https://openairdocs.org/faa-place/NV/Carson%20City), S/N 11613
- [N64PS](https://openairdocs.org/aircraft/N64PS): [Schiff Peter](https://openairdocs.org/faa-owner/SCHIFF%20PETER), [Cookeville, TN](https://openairdocs.org/faa-place/TN/Cookeville), built 1981, S/N 11702

## NTSB investigations

None matched to aircraft with this model.

## FAA accident and incident reports

None matched to aircraft with this model.

## Service difficulty reports (23)

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

- [SDR NI6R202606190066](https://openairdocs.org/sdr/NI6R202606190066), Jun 18, 2026: REGULATOR VALVE. STUCK. DURING FLT, SMOKE IN CABIN, DURING SLOW CRUISE FLT OVER FIRE TRAFFIC AREA, PERFORMED QRH ITEMS, REMOVED SMOKE FROM CABIN. DEPARTED THE FTA TO KCDC LANDED WITHOU
- [SDR 2019FA0000249](https://openairdocs.org/sdr/2019FA0000249), Aug 6, 2019: CONTROL CABLE. SEVERED. LEFT INBOARD FLAP EXTEND CABLE BROKE AT INBOARD WING BELL CRANK CAUSING BOTH LEFT FLAPS TO NOT EXTEND AND CREATED ASYMMETRIC FLIGHT WHEN FLAP SWITCH WAS SELECTE
- [SDR 2019F00229](https://openairdocs.org/sdr/2019F00229), Jun 6, 2019: SKIN. CRACKED. FOUND CRACK IN VERTICAL TAIL SKIN ABOVE "PYRAMID" IN DOUBLER. INSTALLED 5" ACCESS HOLE IN LH VERTICAL SKIN IN REFERENCE TO GTEC, INC ENGINEERING. FOUND MID SPAR
- [SDR LCPR201405010001](https://openairdocs.org/sdr/LCPR201405010001), Apr 22, 2014: WHEEL. FRACTURED. AFTER LANDING, FOUND THE NOSE WHEEL FLAT AND THE NOSE WHEEL RIM BEAD SEAT AREA LT WHEEL HALF FRACTURED.
- [SDR CA110914011](https://openairdocs.org/sdr/CA110914011), Sep 12, 2011: SEAT BACK. CRACKED. (CAN) DURING DESCENT, THE SEAT BACK ON THE PILOT`S SEAT BROKE AND FELL BACKWARDS. THE ACFT WAS ON AUTOPILOT SO THERE WAS NO TEMPORARY LOSS OF CONTROL. THE PILOT
- [SDR EPDA20110804001](https://openairdocs.org/sdr/EPDA20110804001), Aug 4, 2011: SEAL. LEAKING. RT ENGINE FIRE WARNING LIGHT CAME ON DURING CLIMB AT HIGH POWER SETTING. REDUCED POWER AND LIGHT WENT OUT. RETURNED TO DEPARTURE AIRPORT, LANDING UNEVENTFUL. IN
- [SDR 2011FA0000321](https://openairdocs.org/sdr/2011FA0000321), May 17, 2011: SCAVENGE PUMP. FAILED. PILOT REPORTED THAT THE RT ENGINE RPM ACCELERATED UNCOMMANDED FROM 98 PERCENT TO APPROXIMATELY 103.5 PERCENT MOMENTARILY, A FEW SECONDS LATER IT DID IT AGAIN AN
- [SDR 2010FA0001102](https://openairdocs.org/sdr/2010FA0001102), Oct 8, 2010: PULLEY. CHAFED. FLAP PULLEY CHAFES FLAP BRACKET - PREVIOUSLY ADDRESSED IN BOTH AD 98-07-17 AND SB 226.
- [SDR 2010FA0000479](https://openairdocs.org/sdr/2010FA0000479), Apr 10, 2010: SCAVENGE PUMP. DIRTY. DURING FLIGHT, LT ENGINE OIL TEMP NEARED RED LINE BUT DID NOT GO OVER. NO OTHER ENGINE PARAMETERS HAD ANY DEFECT. THE PILOT SHUTDOWN THE LT ENGINE AS A PRECAUTI
- [SDR 2010FA0000178](https://openairdocs.org/sdr/2010FA0000178), Dec 16, 2009: TERMINAL. BURNED. PILOT REPORTED SMELLING SMOKE AND THEN SEEING FLAMES FROM THE RT SIDE FWD SECTION OF GLARE SHIELD. DECLARED AN EMERGENCY, FOLLOWED EMERGENCY PROCEDURES AND AFTE
- [SDR CA091215006](https://openairdocs.org/sdr/CA091215006), Dec 15, 2009: PISTON. CRACKED. (CAN) NDT OUR LANDING GEAR AND RETRACT COMPONENTS EVERY 5 YEARS. COMPLETE AN NDT INSPECTION AT THIS TIME. DURING THIS INSPECTION, A CRACK WAS DISCOVERED. THIS I
- [SDR 2006FA0000899](https://openairdocs.org/sdr/2006FA0000899), Aug 9, 2006: BOLT. SHEARED. DURING ROUTINE INSPECTION FOUND NOSE GEAR LOWER DRAG BRACE BOLT SHEARED AT JUNCTION OF REDUCED DIAMETER BOLT HAD NOT YET CAME OUT OF ITS BORE AND THEREFORE THE 
- [SDR 2005FA0001229](https://openairdocs.org/sdr/2005FA0001229), Aug 3, 2005: CONNECTOR. WORN. PILOT REPORTED INABILITY OF "SERIES" START WITH A/C. UPON INSPECTION FOUND + PIN OF RH BATTERY BROKEN OFF IN BATTERY CONNECTOR. INSPECTED LH BATTERY FOUND + PIN
- [SDR 2008FA0000711](https://openairdocs.org/sdr/2008FA0000711), Oct 3, 2004: WINDOW. CRACKED. ACFT LOST PRESSURIZATION. AFTER LANDING THE RT CABIN WINDOW WAS FOUND CRACKED. AFTER REMOVAL THE CRACK WAS FOUND TO EXTEND FROM THE TOP OF THE WINDOW INTO MOUNT
- [SDR FTU2004F00004](https://openairdocs.org/sdr/FTU2004F00004), Jun 16, 2004: LONGERON. CRACKED. WHILE COMPLYING WITH SB 187, ANTENNA INSPECTION AND MODIFICATION PART 1, THE LT FS 223.98 UPPER FUSELAGE FRAME CHANNEL RETURN FLANGE AT THE LT NR 1 LONGERON INT
- [SDR EPD2003F00001](https://openairdocs.org/sdr/EPD2003F00001), Jun 15, 2003: SWITCH. FAILED. ROCKER SWITCH WHICH CONTROLS THE AIR CONDITIONING AND THE ENVIROMENTAL FANS WAS FOUND OVERHEATED. THE SWITCH HAS LOOSE TERMINALS AND CHECK WITH HIGH RESISTANCE.
- [SDR 20001207SH015](https://openairdocs.org/sdr/20001207SH015), Nov 27, 2000: LOCK. BROKEN. START-LOCK BROKE AND PIN FELL OUT BECAUSE RETAINING COTTER PIN WAS TOO WEAK. (X)
- [SDR 99ZZZX3707](https://openairdocs.org/sdr/99ZZZX3707), Aug 27, 1999: BULKHEAD. CRACKED. THIS AIRCRAFT IS JUST ONE OF FOUR THIS YEAR (OF THE SAME MAKE AND MODEL) THAT HAVE HAD STC SA 8214SW FROM THE COMMANDER SERVICE CENTER (REMOVAL OF THE CLAMSHELL
- [SDR 99ZZZX2480](https://openairdocs.org/sdr/99ZZZX2480), Jun 17, 1999: CLEVIS. FAILED. THE LEFT MAIN LANDING GEAR INBOARD RETRACT CYLINDER CLEVIS BROKE CAUSING THE LEFT MAIN GEAR TO COLLAPSE ON LANDING. THE LEFT GEAR INBOARD EXTENSION/RETRACTION A
- [SDR 97ZZZX2036](https://openairdocs.org/sdr/97ZZZX2036), Apr 29, 1997: ENGINE. LOW OIL PRESS. UPON REACHING FL 26,000 FEET, PILOT OBSERVED OIL PRESSURE DECREASING SLOWLY. THE OIL PRESSURE HAD REACHED A LOW END RED LINE. THE PILOT ELECTED TO SHUT DOWN NR 
- [SDR 96ZZZX1951](https://openairdocs.org/sdr/96ZZZX1951), Mar 21, 1996: SEAL. FAILED. AT 18,000 FEET, PILOT SMELLED SMOKE. CABIN TEMP WENT FULL HOT. SHUT DOWN ENVIRONMENTAL CONTROL UNIT. WHEN ON GROUND, TROUBLESHOOTING FOUND THE CARBON FACE SEAL 
- [SDR 95ZZZX5250](https://openairdocs.org/sdr/95ZZZX5250), Aug 31, 1995: SKIN. CRACKED. DURING THE COURSE OF A 100-HOUR INSPECTION, FOUND THE LT AILERON LEADING EDGE SKIN CRACKED AT THE INBOARD MOST BALANCE WEIGHT ATTACHMENT SCREWS. THE CRACKS RANG
- [SDR 95ZZZX3089](https://openairdocs.org/sdr/95ZZZX3089), Mar 20, 1995: INDICATOR. LEAK. OXYGEN SYSTEM LEAK. FOUND THE LEAK ON THE COPILOT'S MASK. THE FLOW INDICATOR HAS A CLEAR PLASTIC PIECE TO VIEW OXYGEN FLOW. THIS IS THE 2ND MASK FOUND IN THE PA

## STCs that may be installed (OpenAirDocs) (129, 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 SA02571SE](https://openairdocs.org/stc/SA02571SE): Installation of Garmin G500/G600 TXi Integrated Avionics System (Primary Flight Display, Multi-Function Display, and Engine Indicating System Display). Garmin International Inc
- [STC SA01800SE](https://openairdocs.org/stc/SA01800SE): Fabrication and installation of new or replacement of existing instrument panel lights dimmer control. TCW Technologies, LLC
- [STC SA01861SE](https://openairdocs.org/stc/SA01861SE): Fabrication and installation of Landing Light Controller. TCW Technologies, LLC
- [STC SA04837NY](https://openairdocs.org/stc/SA04837NY): Installation of AeroLED's Holdings, LLC., position lights, navigation lights, strobe lights and beacon lights. AeroLED's Holdings, LLC
- [STC SA02019SE-D](https://openairdocs.org/stc/SA02019SE-D): Installation of Garmin Model GTN 625/635/650; 725/750 Navigation System. Garmin International Inc
- [STC SA02511SE](https://openairdocs.org/stc/SA02511SE): Installation of replacement fuel quantity indicator sending unit(s). CiES Inc
- [STC SA11300DS](https://openairdocs.org/stc/SA11300DS): Upgrade previously installed Collins Aerospace Radar Altimeter. BHE & Associates Ltd
- [STC SA8408SW](https://openairdocs.org/stc/SA8408SW): Replace the o-ring seals in the landing gear lower strut seal. Metrea Special Aerospace ISR Inc
- [STC SA02738CH](https://openairdocs.org/stc/SA02738CH): Installation of L-3 Communications Avionics Systems. Acron Aviation Inc
- [STC SA04046CH PAGE 2](https://openairdocs.org/stc/SA04046CH%20PAGE%202): Installation of L-3 GENESIS (TM) Electronic Standby Instrument System (ESI-500/MAG-500). Acron Aviation Inc
- [STC SA02386AK](https://openairdocs.org/stc/SA02386AK): Replacement of existing landing and/or taxi light reflector and bulbs with Light Emitting Diode (LED) lighting systems. AeroLED's Holding LLC
- [STC SA02658SE](https://openairdocs.org/stc/SA02658SE): Installation of Garmin GI 275 Multi-Function Display System. Garmin International Inc
- [STC SA02532AT](https://openairdocs.org/stc/SA02532AT): Installation of subject Michelin tires on appropriate aircraft. For Michelin 5, 6, 8, and 10-inch rim diameter tires on General Aviation Aircraft. Michelin North America Inc
- [STC SA01586SE](https://openairdocs.org/stc/SA01586SE): Group Reduced Vertical Separation Minimum (RVSM). AeroMech Incorporated
- [STC SA02010WI](https://openairdocs.org/stc/SA02010WI): Installation of the Mid-Continent Instruments & Avionics MD23 FLEX Custom Function Display (CFD). Mid-Continent Instruments and Avionics
- [STC SA497GL](https://openairdocs.org/stc/SA497GL): Install Aircraft Wheel and Brake conversion kit 199-80 (MIL-H-5606 system). Kaman Corporation Aircraft Wheel and Brake LLC
- [STC SA1458GL](https://openairdocs.org/stc/SA1458GL): Installation of a Cleveland nose wheel. Kaman Corporation Aircraft Wheel and Brake LLC
- [STC SA02203AK](https://openairdocs.org/stc/SA02203AK): Installation of FlightLogic Synthetic Vision Electronic Flight Information System (EFIS-SV). Genesys Aerosystems Inc
- [STC SA02254AK](https://openairdocs.org/stc/SA02254AK): Installation of "Single Screen", "2 or 3 Screen", "Dual Screen", or "4 or 6 screen". Genesys Aerosystems Inc
- [STC SA02444AK](https://openairdocs.org/stc/SA02444AK): Approval of the L-3 Communications NGT 9000/9000R ADS-B system installed. ADS-B Technologies LLC
- [STC SA09856AC](https://openairdocs.org/stc/SA09856AC): Installation of BendixKing Aerowave 100 In-flight Data Link System for non-essential, non-required aircraft Cabin Systems & Equipments. Honeywell International Inc (Bendix King)
- [STC SA11174SC PAGE 2](https://openairdocs.org/stc/SA11174SC%20PAGE%202): Installation of BendixKing by Honeywell KSN 770 and KSN 765 WAAS LPV approach capable nav/comm systems. Honeywell International Inc (Bendix King)
- [STC SA02265SE](https://openairdocs.org/stc/SA02265SE): Installation of a camera housing. Airborne Sensor LLC
- [STC ST01930LA](https://openairdocs.org/stc/ST01930LA): Installation of Sandel Avionics SN4500 Electronic Horizontal Situation Indicator (EHSI). Sandel Avionics LLC
- [STC SA02075SE](https://openairdocs.org/stc/SA02075SE): Installation of a Mid-Continent MD835( ) Lithium Ion Battery. Mid-Continent Instrument Co. Inc
- [STC SA02426AK](https://openairdocs.org/stc/SA02426AK): Approval of the FreeFlight FDL-978-TX ADS-B system installed. FreeFlight Systems
- [STC SA09763DS](https://openairdocs.org/stc/SA09763DS): Installation of an S-TEC 01326 Digital Flight Control System (DFCS). S-TEC Corporation
- [STC SA04489NY](https://openairdocs.org/stc/SA04489NY): Installation of Astronics Max-Viz Enhanced Vision System. Air Spray (1967) Ltd
- [STC SA10236SC](https://openairdocs.org/stc/SA10236SC): Installation of a GDC 31 Roll Steering Converter. DAC International Inc
- [STC SA01452CH](https://openairdocs.org/stc/SA01452CH): Installation of an air ambulance conversion kit. Med-Pac Inc
- [STC SA01714WI](https://openairdocs.org/stc/SA01714WI): Installation of a Garmin transponders: (a) GTX 330/330D/33/33D with ADS-B Out functionality; (b) GTX 335/335R/345/345R with ADS-B Out and In functionality; or (c) GTX 335R/345R with ADS-B Out functionality in select airplanes installed with G950/G1000 systems. Garmin International Inc
- [STC SA4583SW](https://openairdocs.org/stc/SA4583SW): Installation of an electrically-driven Vapor Cycle, Freon or Refrigerant R-134a, Air Conditioning System. Air Comm Corporation
- [STC SA00344BO PAGE 2](https://openairdocs.org/stc/SA00344BO%20PAGE%202): Installation of Parmetheus Plus LED PAR36 and PAR46 taxi and landing lights. Whelen Aerospace Technologies
- [STC SA00098SE](https://openairdocs.org/stc/SA00098SE): Installation of emergency medical stretcher, oxygen, and electrical systems. LifePort LLC
- [STC SA00765DE](https://openairdocs.org/stc/SA00765DE): Installation of Automatic Dependent Surveillance Broadcast (ADS-B) Out functionality using the BendixKing KT74 Transponder and qualified position sensor. Peregrine
- [STC SA04165NY](https://openairdocs.org/stc/SA04165NY): Installation of Latitude Technologies Skynode S200 Satcom system must be performed. Latitude Technologies Corporation
- [STC SA02153LA-D PAGE 2](https://openairdocs.org/stc/SA02153LA-D%20PAGE%202): Installation of Garmin G600 Primary Flight Display (PFD) and Multifunction Display (MFD) System. Garmin International Inc
- [STC SA02503AK](https://openairdocs.org/stc/SA02503AK): Installation of AMSAFE State of the Art Restraint System (SOARS) inflatable restraints. AMSAFE Inc
- [STC SA02013CH](https://openairdocs.org/stc/SA02013CH): Installation of Avidyne Corporation Traffic Advisory System (TAS). Avidyne Corporation
- [STC SA01933LA-D](https://openairdocs.org/stc/SA01933LA-D): Installation of Garmin Model 400W / 500W Series GPS-WAAS Navigation System. Garmin International Inc
- [STC SA02212AK](https://openairdocs.org/stc/SA02212AK): Replacement of existing landing and/or taxi light reflector and bulbs with high intensity discharge (HID) lighting systems. Seaplanes North LLC
- [STC SA00343BO](https://openairdocs.org/stc/SA00343BO): Installation of a single configuration or a dual configuration Avidyne Corporation Integrated Flight Display, Model IFD540 loaded with Release 10.0 software (or later FAA approved release). Avidyne Corporation
- [STC SA00352BO PAGE 2](https://openairdocs.org/stc/SA00352BO%20PAGE%202): Installation of an Avidyne Corporation Mode A/C/S Transponder with ADS-B Out capability, Model AXP340 loaded with Version 3.13 software (or later FAA approved version),. Avidyne Corporation
- [STC SA1177GL](https://openairdocs.org/stc/SA1177GL): Install Aero Medical Products Mfg., Inc. Air Ambulance Stretcher P/N 125 using Installation Kit P/N 800 in accordance with Installation and Operating Instructions, Form EA 109K, dated April 23, 2001, or later FAA approved revisions. The Medical Oxygen System Kit P/N 807 is an FAA approved option. The Inverter/Pump Kit No. 812 may be installed in accordance with Inverter/Pump Installation Instructions, EA Form 170, dated June 9, 2001, or later FAA approved revisions. Paul/ Lanna Egan LLC
- [STC SA00149BO](https://openairdocs.org/stc/SA00149BO): Installation of Aircraft Components, Inc. Volt and Vac Alert System, P/N 2044-1. Aircraft Components Inc
- [STC SA02547AT](https://openairdocs.org/stc/SA02547AT): Installation of a Voice Alert System. Aircraft Components Inc
- [STC SA03658AT](https://openairdocs.org/stc/SA03658AT): Installation of a Voice Alert System to incorporate as primary annunciators for stall and gear warnings. Aircraft Components Inc
- [STC SA02119SE PAGE 2](https://openairdocs.org/stc/SA02119SE%20PAGE%202): Installation of Garmin GDL 88 ADS-B UAT Transceiver System. Garmin International Inc
- [STC SA01969SE](https://openairdocs.org/stc/SA01969SE): Installation of a Mid-Continent MD302 Standby Attitude Module. Mid-Continent Instruments and Avionics
- [STC SA02453AK](https://openairdocs.org/stc/SA02453AK): Increase maximum ramp weight to 11,050 lbs. and increase maximum takeoff weight to 11,000 lbs. when operating in restricted category for the special purpose of Forest Service and Wildlife Conservation/Aerial Survey. Clearwater Air Inc

All 129: https://openairdocs.org/model/twin-commander-690c/stcs.md

## The same model under other registry codes

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

- [Rockwell International 690C](https://openairdocs.org/model/rockwell-international-690c): 21 registered aircraft, registry code 7630517
- [Gulfstream AM Corp Comm Div 690C](https://openairdocs.org/model/gulfstream-am-corp-comm-div-690c): 14 registered aircraft, registry code 3970404

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