# SDR DXTA2026010806450

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 5, 2026
- Submitted: January 8, 2026
- Operation: Air carrier
- Aircraft: [N570QS](https://openairdocs.org/aircraft/N570QS), registered now
- Make and model: Cessna 680A
- Registry model: [Cessna 680A](https://openairdocs.org/model/cessna-680a) (OpenAirDocs)
- Aircraft serial: 680A0125
- Aircraft time: 8,867 hours, 5,799 cycles
- System (JASC): [3260 · Landing Gear Position and Warning](https://openairdocs.org/jasc/3260)
- Part: Downlock Switch
- Part number: 603733
- Condition: Faulty
- Location: Mlg
- Stage of operation: CL
- How discovered: O
- Nature of condition: J
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/DXTA2026010806450

## Discrepancy

ON DEPARTURE OUT OF BOS AFTER SELECTING GEAR UP, GOT A YELLOW CAS- GEAR DISAGREE RT & A YELLOW X RT GEAR INDICATION.  COMPLETED THE QRH PROCEDURE FOR. GEAR DISAGREE.  BEGAN TROUBLESHOOTING, GATHERED MANUALS, REFERENCES, & PRIOR HISTORY.  SUSPECT THAT THE ISSUE IS COMING FROM RT MLG DOWNLOCK SWITCH.  BEGAN WITH METERING CHECKS & PERFORMED CONTINUITY CHECKS ON BOTH  DOWNLOCK AND UPLOCK SWITCHES. BOTH SWITCHES, GROUND METERED GOOD. THEN RECONFIGURED ACFT BACK TO NORMAL CONDITION DUE TO EMERGENCY GEAR BOTTLE BEING OPERATED.AFTER. 4'0 THE RESETJACKED UP AIRCRAFT AND HOOKED UP ELECTRICAL AND HYDRAULIÇ POWER. PERFORMED THE LANDING GEAR OPERATIONAL CHECKS. ONE OUT OF THE 15 GEAR SWING NOTICED WHEN HANDLE WAS SELECTED DOWN THE RH DOWN INDICATION WENT FROM GREEN TO AMBER BACK TO GREEN FOR ABOUT A SECOND, OTHER THAN THAT ALL OPERATIONAL CHECKS WERE GOOD. THEN GAINED ACCESS TO THE DOWN LOCK SWITCH AND BEGAN TO REMOVE THE / SEALANT. AFTER WAS ABLE TO REMOVE THE SWITCH FROM THE ACTUATOR HOUSING. INSPECTED THE HOUSING AND FOUND MOISTURE AND DEBRIS INSIDE. CONTINUED WITH REPLACING THE SWITCH. PER THE MANUAL IT SAYS TO PERFORM THE LANDING GEAR DOWNLOCK SWITCH TEST FOR THIS ACTUATORS PART NUMBER. CE-680A MM 32-30-15.NEXT STEP IS TO CONTINUE WITH THE LANDING GEAR DOWNLOCK SWITCH TEST AND PROCEED WITH THOSE FINDINGS. FOLLOWING CIRCUIT BREAKERS ARE PULLED: FLIGHT HOUR METER, L FUEL BOOST, R FUEL BOOST AND, IN THE BAGGAGE L BOOST PUMP, R BOOST PMP. PANEL 316AR IS TAGGED ON TOP OF CART NEXT TO AIRCRAFT. NEXT STEP IS TO CONTINUE WITH THE LANDING GEAR DOWNLOCK SWITCH TEST AND PROCEED WITH THOSE FINDINGS. FOLLOWING CIRCUIT BREAKERS ARE PULLED: FLIGHT,HOUR.METER, L FUEL.BOOST, R FUEL BOOST AND, IN THE BAGGAGE L BOOST-PUMP, R BOOST PMP. PANEL 316AR IS TAGGED ON TOP OF CART NEXT TO ACFT.CONTINUED & PERFORMED LANDING GEAR DOWNLOCK SWITCH CONTINUITY CHECKS GOOD. ALSO PERFORMED MEASUREMENT OF DOWNLOCK SWITCH / ACTUATION LEVER AND VERIFIED IT IS WITHIN SPEC WITH A MEASUREMENT OF .50 INCH AND A SPEC OF (.48INCH +/- .05 INCH). MOVED ON AND PERFORMED CONTINUITY CHECKS FROM DOWNLOCK SWITCH CONNECTOR PG012 TO WHEEL WELL DISCONNECT CONNECTOR GOOD, VERIFIED GROUNDS ARE GOOD AND NO OPENS OR SHORTS WHILE MANIPULATING HARNESS. NEXT PERFORMED / CONTINUITY CHECKS OF RH UP-LOCK SWITCH (SG008) FROM THE WHEEL WELL CONNECTOR THRU THE UP-LOCK SWITCH, CONTINUITY CHECKS FAILED, SWITCH HAS HIGH RESISTANCE ON ALL PINS IN BOTH UP AND LOCKED OR UN-LOCKED DIRECTIONS, NEEDS TO BE REPLACED. INFORMED TEXTRON AND MCC (ERIC HOLCOMB & BILL WILLIAMS2) OF FINDINGS, THEU ELECT TO REPLACE BOTH THE / DOWN-LOCK SWITCH AND UP-LOCK SWITCHES. PLACED PARTS ON ORDER. REMOVED DOWN-LOCK SWITCH(SG002) PN: 6-0373-3 SN: NA, AND INSTALLED, RIGGED, SEALED AND SAFE-TIED REPLACEMENT SWITCH PN: 6-0373-3 SN: NA. NEED TO CONTINUE WITH GEAR SWINGS AND OPERATIONAL CHECKS. WORK DONE IN REF TO 680A AMM CH 32-30-15. VOLT METER USED SN: 86140167 CAL DUE 14 JUL 2026 NEED TO REPLACE RH UP-LOCK SWITCH, RIG AND OPS CHECKS GEAR SWINGS (POO) NEED TO PERFORM OPERATIONAL CHECKS OF RH DOWN LOCK SWITCH GEAR SWINGS FOLLOWING CIRCUIT BREAKERS ARE PULLED: FLIGHT HOUR METER, L FUEL BOOST, R FUEL BOOST AND, IN THE BAGGAGE L BOOST PUMP, R BOOST PMP. PANEL 316AR IS TAGGED ON TOP OF CART NEXT TO AIRCRAFT. WHILE REMOVING THE RH UP LOCK SWITCH THE SCREWS WERE VERY-WORN 'AND CORRODED, CAUSING THE SCREWS TO STRIP WHEN ATTEMPTING TO TAKE OFF. HAD TO USE VICE GRIPS IN AN AREA WITH VERY LIMITED SPACE, AFTER SOME.TIME WAS ABLE TO REMOVE THE STRIP SCREWS.

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