# Service difficulty reports: Continental GTSIO-520-N

A list on [Continental GTSIO-520-N](https://openairdocs.org/engine/continental-gtsio-520-n.md).

Newest first. General aviation reporting is voluntary.

Page 1 of 2 · 54 reports

- [SDR 2026FA0000551](https://openairdocs.org/sdr/2026FA0000551.md): Gasket · degraded · Jun 30, 2026 · N68685 · Cessna 421C · Cabin Cooling System
  > FAILED GASKET PN: 5154056-2 FOR THE AC COMPRESSOR, RESULTING IN A SEVERE ENGINE OIL LEAK, SPRAYING ENGINE OIL ON THE EXHAUST SYSTEM.
- [SDR 2018FA0000508](https://openairdocs.org/sdr/2018FA0000508.md): Pressure Switch · failed · Dec 11, 2018 · N605SR · Cessna 421C · Heating System
  > IN SPITE OF NO REQUIREMENT TO TEST THIS PRESSURE SWITCH. FOUND THIS PRESSURE SWITCH FAILED IN THE CLOSED POSITION.
- [SDR CXUA201803210140](https://openairdocs.org/sdr/CXUA201803210140.md): Engine · failed · Dec 7, 2017 · N726RT · Cessna 421C · Engine (Reciprocating)
  > RIGHT ENGINE FAILED.
- [SDR NI6R201503050024](https://openairdocs.org/sdr/NI6R201503050024.md): Crankcase · cracked · Mar 5, 2015 · N505SF · Cessna 340A · Reciprocating Engine Cylinder Section
  > DURING INVESTIGATION OF LT ENGINE OIL LEAK, A CRACK WAS DISCOVERED IN THE ENGINE CASE OTBD SIDE RUNNING BETWEEN THE NR 2 & NR 4 CYLINDERS.
- [SDR NI6R201502260023](https://openairdocs.org/sdr/NI6R201502260023.md): Pin · broken · Feb 26, 2015 · N505SF · Cessna 340A · Reciprocating Engine Power Section
  > RT ENGINE NR 5 WRIST PIN, INTERNAL ALUMINUM PIECE BROKEN.
- [SDR IGXR2014FA0000710](https://openairdocs.org/sdr/IGXR2014FA0000710.md): Line · failed · Dec 15, 2014 · N122TJ · Cessna 421C · Aircraft Fuel Distribution System
  > AFTER TAKEOFF, LT ENGINE STOPPED PRODUCING FULL POWER. AIRCRAFT SAFELY RETURNED BACK WITH 1 ENGINE. EXAMINED LT ENGINE AND DISCOVERED CYL NR 6 FUEL LINE DETACHED FROM FUEL MANIFOLD, LINE FAILED AT SOLDER JOINT AT MANIFOLD END. R & R CYLINDER NR 6 FUEL LINE
- [SDR 2013FA0000674](https://openairdocs.org/sdr/2013FA0000674.md): Boot · failed · Nov 8, 2013 · N720FS · Cessna 421C · Airfoil Anti/De-ice System
  > EYELET ATTACHMENT NOT FULLY INSULATED ALLOWING DIRECT SHORT TO GROUND ON ONE DE-ICE BOOT. THE SECOND WAS A FAILED INBD CIRCUIT.
- [SDR YN8R201307310001](https://openairdocs.org/sdr/YN8R201307310001.md): Pump · leaking · Jul 31, 2013 · Cessna 421C · Engine Fuel Pump
  > AFTER FUELING, PILOT NOTICED FUEL DRIPPING FROM GANG DRAIN BENEATH ENGINE. DISCOVERED FUEL WAS DRIPPING FROM ENGINE DRIVEN FUEL PUMP AT A RATE OF A DROP EVERY THREE SECONDS.
- [SDR 2012FA0000810](https://openairdocs.org/sdr/2012FA0000810.md): Cylinder · detached · Nov 21, 2012 · N2668A · Cessna 421C · Reciprocating Engine Cylinder Section
  > NR 5 CYLINDER UPPER BASE STUDS FAILED - THREE BLIND STUDS & 1 CASE THROUGH-STUD. CYLINDER PARTIALLY DISLODGED FROM CRANKCASE, LOSS OF ENGINE OIL, SIGNIFICANT VIBRATION, PRECAUTIONARY IN-FLIGHT SHUTDOWN AND FEATHER.
- [SDR 2008FA0000625](https://openairdocs.org/sdr/2008FA0000625.md): Bushing · cracked · Sep 5, 2008 · N410AJ · Cessna 421C · Reciprocating Engine Power Section
  > DURING CYLINDER NR 5 REMOVAL TO CORRECT HIGH OIL CONSUMPTION, FOUND CONNECTING ROD PISTON PIN BUSHING CRACKED WITH LARGE PIECE MISSING FROM EDGE. FAILURE IS AS NOTED IN MFG SB SB07-1. REMOVED ALL 6 CYLINDERS FROM ENGINE AND FOUND 4 MORE BUSHINGS CRACKED IN S
- [SDR 2007FA0000944](https://openairdocs.org/sdr/2007FA0000944.md): Starter · shorted · Oct 12, 2007 · N421KD · Cessna 421C · Engine Starter
  > OVERHAULED STARTER FAILED AFTER 30 HOURS. (K)
- [SDR 2006FA0001178](https://openairdocs.org/sdr/2006FA0001178.md): Clamp · cracked · Dec 12, 2006 · Cessna 421 · Exhaust Turbocharger
  > DURING PROGRESSIVE INSPECTION FOUND LT ENGINE TURBOCHARGER TO TAILPIPE CLAMP CRACKED ALONG CIRCUMFERENCE, APPROX. 4 INCH CRACK. FOUND SAME PN CLAMP ON THE RT ENGINE OF THIS AIRCRAFT TO BE CRACKED 7 HOURS PREVIOUSLY.
- [SDR 2006FA0001111](https://openairdocs.org/sdr/2006FA0001111.md): Clamp · cracked · Nov 21, 2006 · Cessna 421C · Engine Collector/Tailpipe/Nozzle
  > PN 2274-50 (ALSO PN NH1000897-50) CLAMP HOLDING TAILPIPE TO THE TURBO CRACKED LENGTHWISE ALONG THE CIRCUMFERENCE OF THE CLAMP. TOTAL LENGTH OF THE CRACK IS 3 INCHES.
- [SDR 2006FA0000985](https://openairdocs.org/sdr/2006FA0000985.md): Line · ruptured · Sep 22, 2006 · N469S · Cessna 421C · Engine Fuel Distribution
  > FUEL HOSE RUPTURED, SPRAYING FUEL ON THE HOT EXHAUST MANIFOLD TO TURBO CHARGER CAUSING AN ENGINE FIRE ON THE GROUND. (K)
- [SDR ISW1520050019](https://openairdocs.org/sdr/ISW1520050019.md): Adapter · failed · Feb 23, 2006 · N421LH · Cessna 421C · Engine Starting System
  > THE ENGINE QUIT RUNNING AND SEIZED DURING FLIGHT. THE STARTER ADAPTER FAILED AND CAUSED THE ENGINE TO SEIZE. MAINTENANCE RECORDS SHOW THAT THE STARTER WAS REPLACED TWO TIMES BECAUSE OF HARD STARTING. ONCE AT 99 HOURS AND AGAIN AT 90 HOURS PRIOR TO ENGINE FAI
- [SDR 2005FA0001618](https://openairdocs.org/sdr/2005FA0001618.md): Distributor Gear · disintegrated · Dec 15, 2005 · N2740 · Dhav DHC2* · Magneto/Distributor
  > DURING CRUISE LT ENGINE BEGAN TO RUN ROUGH. MAINTENANCE TRACED PROBLEM TO LT MAG. UPON OPENING THE MAGNETO, DISCOVERED THE DISTRIBUTOR GEAR MISSING 98 PERCENT OF ITS TEETH WITH MANY BROKEN PIECES AND SHAVINGS INSIDE THE MAG. THE DISTRIBUTOR GEAR BUSHING IS
- [SDR AU510001911](https://openairdocs.org/sdr/AU510001911.md): Gear · damaged · Dec 12, 2005 · Cessna 421C · Reciprocating Engine Power Section
  > (AUS) ENGINE CRANKSHAFT GEAR MISSING TEETH. SUSPECT CAUSED BY A PIECE OF METAL FROM THE STARTER ADAPTER GEAR JAMMING IN THE GEAR TEETH. METAL CONTAMINATION OF ENGINE. (CASA NR 510001911)
- [SDR VA12004F00000](https://openairdocs.org/sdr/VA12004F00000.md): Crankshaft · broken · Aug 2, 2004 · N421GF · Cessna 421C · Reciprocating Engine Power Section
  > CRANKSHAFT HAD BEEN ULTRASONIC INSPECTED IAW APPLICABLE CSB 99-6A DURING OVERHAUL. RETURNED TO SERVICE AND AFTER 141.1 HOURS, FAILED IN SAME GENERAL OF REQUIRE INSPECTIONS. BROKEN AT NR 3 MAIN JOURNAL TO NR 5 ROD THROW.
- [SDR 2004FA0000632](https://openairdocs.org/sdr/2004FA0000632.md): Line · cracked · Jun 15, 2004 · N421GF · Cessna 421C · Engine Fuel Distribution
  > PILOT EXPERIENCED EGT FLUXUATIONS, MADE PRECAUTIONARY LANDING. INSPECTION REVEALED CYLINDER NR 4 INJECTOR LINE WAS CRACKED AND LEAKING FUEL AT THE BASE OF THE BRAZED ON SLEEVE BETWEEN THE SLEEVE AND THE BALL END.
- [SDR J7B2003F00001](https://openairdocs.org/sdr/J7B2003F00001.md): Coil · separated · Oct 10, 2003 · N421GF · Cessna 421C · Propeller Synchronizer Section
  > ON TAKE OFF THE RT ENGINE FEATHERED. INSPECTION REVEALED PROPELLER SYNCROPHASER COIL HAD BECOME SEPARATED FROM THE GOVERNOR BODY, CAUSING THE PROPELLER TO FEATHER. THE ATTACHING STUDS ON THE COIL HAD SHEARED AND BECAME BOUND UP WITH THE FLYWEIGHT ASSY. PULL
- [SDR AUS20030839](https://openairdocs.org/sdr/AUS20030839.md): Housing · faulty · Jul 16, 2003 · Cessna 421C · Reciprocating Engine Oil System
  > (AUS) RT ENGINE OIL PUMP HOUSING FAULTY.
- [SDR 2002F00038](https://openairdocs.org/sdr/2002F00038.md): Piston · failed · Jan 17, 2002 · N763CA · Cessna 421C · Reciprocating Engine Cylinder Section
  > TRANSISITIONING FROM TAKE-OFF TO CLIMB PHASE OF FLIGHT, AFTER REDUCING POWER NR 1 ENGINE SHUTDOWN. PILOT FEATHERED PROP AND MADE UNEVENTFUL LANDING. REMOVAL OF NR 5 CYLINDER REVEALED SEVERE DAMAGE TO THE TOP OF THE PISTON, WITH BROKEN RINGS. VALVE WERE REALITI
- [SDR 2002F00037](https://openairdocs.org/sdr/2002F00037.md): Torque Tube · corroded · Dec 21, 2001 · N6793V · Cessna 421C · Elevator Control System
  > DURING A AAIP 100 HOUR INSPECTION, SEVERE CORROSION WAS NOTED IN THE RIGHT ELEVATOR TORQUE TUBE. THE CORROSION (RUST) HAS DEPLETED AT LEAST 75% OF THE MATERIAL THICKNESS. THE LEFT ELEVATOR WAS REMOVED TO INSPECT THE TORQUE TUBE FOR CORROSION. NONE WAS NOTED. T
- [SDR 2001F00021](https://openairdocs.org/sdr/2001F00021.md): Nut · cracked · Jun 20, 2001 · N6865Z · Cessna 421C · Reciprocating Engine Power Section
  > DURING ANNUAL INSPECTION FOUND NUT CRACKED. NOTHING UNUSUAL NOTICED AS FAR AS INSTALLATION WAS CONCERNED. FOUND THAT NUT CRACKED IN THE CENTER OF THE V ON THE SMALLEST DIAMETER PART OF THE NUT. INSTALLED NEW NUT AND TORQUED TO SPECS. OTHER ENGINE CHECKED A
- [SDR AUS20010645](https://openairdocs.org/sdr/AUS20010645.md): Bearing · failed · Jun 12, 2001 · Cessna 421C · DC Generator-Alternator
  > (AUS) LH ALTERNATOR. INVESTIGATION FOUND REAR BEARING COLLAPSED CAUSING DRIVE ADAPTER FAILURE AND METAL CONTAMINATION OF THE ENGINE.
- [SDR 20010515AP005](https://openairdocs.org/sdr/20010515AP005.md): Exhaust Header · defective · May 4, 2001 · N6867D · Cessna 421C · Engine Collector/Tailpipe/Nozzle
  > THIS UNIT IS MANUFACTURED IN TWO HALVES, WHERE THE UPPER & LOWER HALVES WELDED TOGETHER (AT THE WASTE GATE FLANGE) THERE IS A HOLE AT THE WELD AREA ON EACH SIDE. THE REPLACMENT PART HAS AN ADDITIONAL WELD IN THESE AREAS THAT ARE NOT PRESENT ON THE DEFECTIVE P
- [SDR AU001155](https://openairdocs.org/sdr/AU001155.md): Pipe · corroded · Dec 11, 2000 · Cessna 421C · Crew Oxygen System
  > (AUS) OXYGEN PIPE CORRODED AND LEAKING IN AREA BEHIND PILOTS SEAT SIDELINING. PIPE CONTAINED PIN HOLE CORROSION IN THE AREAS TOUCHING THE SCAT HOSE.
- [SDR 20001206SH032](https://openairdocs.org/sdr/20001206SH032.md): Line · loose · Nov 20, 2000 · N4119M · Cessna 421C · Exhaust Turbocharger
  > THE LEFT ENGINE TURBOCHARGER COMPRESSOR DISCHARGE REFERENCE LINE CAME OFF AT CRUISE POWER AT 15,500 FEET CAUSING THE ENGINE TO DIE WITH AN EXCESSIVELY RICH MIXTURE. THE PILOT DID NOT ATTEMPT LEANING DURING TROUBLESHOOTING AND FEATHERED THE ENGINE, LANDED SAFE
- [SDR 20000331SH025](https://openairdocs.org/sdr/20000331SH025.md): Stud · failed · Mar 6, 2000 · N421CH · Cessna 421 · Reciprocating Engine Cylinder Section
  > DURING INSPECTION OF OIL LEAK, FOUND NR 5 CYLINDER BASE FRONT LOWER MOUNT STUD BROKEN. POSSIBLY, THE STUD WAS HARD AND BROKE UNDER STRESS. (X)
- [SDR 20000403SH002](https://openairdocs.org/sdr/20000403SH002.md): Stud · failed · Mar 6, 2000 · N421LH · Cessna 421C · Reciprocating Engine Cylinder Section
  > DURING NORMAL ENGINE OPERATION, NOTICED OIL LEAK ON FRONT OF ENGINE. AFTER CLEANING AND INSPECTION, FOUND THE FRONT THROUGH-STUD BROKEN. POSSIBLE CAUSE COULD BE IMPROPER HARDENING OF THE BOLT. (X)
- [SDR 99ZZZX4549](https://openairdocs.org/sdr/99ZZZX4549.md): Support Pin · failed · Sep 21, 1999 · N6VH · Cessna 421C · Reciprocating Engine Rear Section
  > FOREIGN OBJECT DAMAGE WITHIN LEFT ENGINE ASSEMBLY CAUSED IDLER GEAR SUPPORT PIN BETWEEN MAGNETO DRIVES TO SHEAR CAUSING MOUNT STUDS TO BREAK AND THE GEAR IT RIDES ON TO ROTATE AND BECOME UNMESHED. IT AFFECTED MAGNETO TIMING AND CAUSED ENGINE TO LOSE POWER AND
- [SDR 99ZZZX2275](https://openairdocs.org/sdr/99ZZZX2275.md): Crack · cracked · May 1, 1999 · N421GF · Cessna 421C · Engine (Reciprocating)
  > PILOT REPORTED EXCESSIVE OIL LEAK ON RIGHT ENGINE CAWLING PULLED AND 3 INCH - 4 INCH CRACK NOTED AT NR 5 CYLINDR BASE. IDENTIDAL PROBLEM OCCURRED.
- [SDR 99ZZZX1733](https://openairdocs.org/sdr/99ZZZX1733.md): Fuel Line · broken · Apr 12, 1999 · N264DC · Cessna 421C · Aircraft Fuel Distribution System
  > PILOT LANDED AND STATED THAT DURING FLIGHT, THE LEFT ENGINE STARTED TO VIBRATE AND EGT INDICATION ON NR 4 CYLINDER WENT TO ZERO. PILOT ELECTED TO SHUT DOWN THE LEFT ENGINE, FEATHER THE PROPELLER AND CONTINUE ON TO HOME BASE. INSPECTION OF THE LT ENGINE NR 4
- [SDR 99ZZZX1200](https://openairdocs.org/sdr/99ZZZX1200.md): Bolt · broken · Mar 1, 1999 · N215MP · Cessna 421C · Reciprocating Engine Power Section
  > WHILE TROUBLESHOOTING AN OIL LEAK, THE LOWER THRU-BOLT BETWEEN THE NR 4 AND NR 5 CYLINDER WAS FOUND BROKEN APPROXIMATELY.50 INCH FROM THE END. AFTER CYLINDER REMOVAL AND COMPLETE CRANKCASE AND TORQUE INSPECTION, NO OTHER DEFECTS WERE FOUND.
- [SDR 99ZZZX1457](https://openairdocs.org/sdr/99ZZZX1457.md): Adapter · spalled · Feb 24, 1999 · N745CA · Cessna 421C · Reciprocating Engine Rear Section
  > AIRCRAFT IN FOR ROUTINE (SCHEDULED) 100 HOUR INSPECTION. STARTER ADAPTERS WERE REMOVED FROM BOTH ENGINES, AND INSPECTED IAW TCM SB NR CS894-4A. THE ADAPTER ASSY AND CRANKSHAFT GEAR ON THE NR 2 ENGINE (ITEM 3) DID NOT PASS INSPECTION CRITERIA OUTLINED, (DEEP SP
- [SDR 99ZZZX1458](https://openairdocs.org/sdr/99ZZZX1458.md): Gear · spalled · Feb 24, 1999 · N745CA · Cessna 421C · Reciprocating Engine Power Section
  > AIRCRAFT IN FOR ROUTINE (SCHEDULED) 100 HOUR INSPECTION. STARTER ADAPTERS WERE REMOVED FROM BOTH ENGINES, AND INSPECTED IAW TCM SB NR CS894-4A. THE ADAPTER ASSY AND CRANKSHAFT GEAR ON THE NR 2 ENGINE (ITEM 3) DID NOT PASS INSPECTION CRITERIA OUTLINED, (DEEP SP
- [SDR 99ZZZX583](https://openairdocs.org/sdr/99ZZZX583.md): Rod · failed · Jan 15, 1999 · N637DT · Cessna 421C · Reciprocating Engine Cylinder Section
  > ENGINE STARTED EXTREME VIBRATION CLIMBING THROUGH 13,000 FEET. OIL LEAK OBSERVED COMING FROM LOUVERS. ENGINE WAS SHUT DOWN AND PROPELLER FEATHERED. INSPECTION REVEALED 2 HOLES IN CASE HALVES ABOVE NR 1 AND NR 2 CYLINDERS. NR 1 CYLINDER ROD BROKEN. SEVERAL
- [SDR 99ZZZX365](https://openairdocs.org/sdr/99ZZZX365.md): Crankcase · cracked · Jan 4, 1999 · N883FL · Cessna 421C · Reciprocating Engine Cylinder Section
  > DURING A PHASE 3 INSPECTION, A 1.50 INCH CRACK WAS NOTED ABOVE THE LEFT ENGINE, NR 2 CYLINDER. PER M90-17, THIS WAS IN A NON-CRITICAL AREA, SO THE CRACK WAS SCRIBE MARKED AND RETURNED TO SERVICE. DURING THE PHASE 4 INSPECTION, THE CRACK WAS NOTED TO HAVE PRO
- [SDR 98ZZZX3441](https://openairdocs.org/sdr/98ZZZX3441.md): Bearing · worn · Aug 10, 1998 · N411MZ · Cessna 421C · Magneto/Distributor
  > DURING ROUTINE INSPECTION OF THE AIRCRAFT MAGNETO TO ENGINE TIME CHECK REVEALED 15 DEGREE DISCREPANCY. FURTHER INSPECTION FOUND MAGNETO CAMSHAFT LOOSE IN THE HOUSING. SUBMITTER STATES EXTREME WEAR OF CAM BEARING DUE TO INADEQUATE LUBRICATION OF BEARING DURIN
- [SDR 98ZZZX3442](https://openairdocs.org/sdr/98ZZZX3442.md): Bearing · worn · Aug 10, 1998 · N411MZ · Cessna 421C · Magneto/Distributor
  > DURING ROUTINE INSPECTION OF THE AIRCRAFT, MAGNETO TO ENGINE TIME CHECK REVEALED 15 DEGREE DISCREPANCY. FURTHER INSPECTION FOUND MAGNETO CAMSHAFT LOOSE IN THE HOUSING. SUBMITTER STATES EXTREME WEAR OF CAM BEARING DUE TO INADEQUATE LUBRICATION OF BEARING DURI
- [SDR 98ZZZX2032](https://openairdocs.org/sdr/98ZZZX2032.md): Driven Gear · worn · Apr 20, 1998 · N745CA · Cessna 421C · Reciprocating Engine Oil System
  > PILOT REPORTED TACH INOPERATIVE AND LOSS OF OIL PRESSURE. INSPECTION REVEALED THE OIL PUMP DRIVE GEAR ASSY SHAFT HAD SHEARED AT POINT OF ENGAGEMENT TO THE CAMSHAFT GEAR AND SUBSEQUENT TACH INDICATION AND OIL PRESSURE LOSS OCCURRED. FURTHER INSPECTION OF THE
- [SDR 98ZZZX1986](https://openairdocs.org/sdr/98ZZZX1986.md): Valve Spring · failed · Mar 4, 1998 · N748CA · Cessna 421C · Reciprocating Engine Cylinder Section
  > PILOT REPORTED VIBRATION ON RT SIDE OF AIRCRAFT DURING TAKEOFF ROLL AND CLIMB OUT. COULD NOT CORRECT WITH ENGINE CONTROLS (RPM, M.A.P., FUEL OR MAGS). RETURNED TO AIRPORT MAINT FACILITY AND REPORTED OUT OF BALANCE PROP. UPON MAINT GROUND RUN, ENG RAN ROUGH,
- [SDR 98ZZZX2033](https://openairdocs.org/sdr/98ZZZX2033.md): Driven Gear · seized · Feb 20, 1998 · N745CA · Cessna 421C · Reciprocating Engine Oil System
  > PILOT REPORTED YAW IN AIRCRAFT AND APPARENT LOSS OF POWER ON LT ENGINE (LOW RPM AND MAP). PILOT EXERCISED EMERGENCY PROCEDURES TO RESTORE POWER, BUT WAS UNSUCCESSFUL AND THE ENG WAS SHUT DOWN IN-FLIGHT. PROP WAS ALREADY IN FEATHER POSITION WHICH WOULD INDICA
- [SDR AU980159](https://openairdocs.org/sdr/AU980159.md): Valve · worn · Feb 13, 1998 · Cessna 421C · Fuel Transfer Valve
  > (AUS) INLET FUEL VALVE ASSEMBLY WORN. VALVE FAILED TEST IAW AD/CESSNA400/100A4 DUE TO WORN VALVE STEM.
- [SDR 97ZZZX5162](https://openairdocs.org/sdr/97ZZZX5162.md): Valve Seat · failed · Nov 21, 1997 · N6798V · Cessna 421C · Reciprocating Engine Cylinder Section
  > NEW TCM CYLINDER ASSYS INSTALLED AT ENGINE OVERHAUL. DATE STAMPED ON ROCKER BOSS: 7-97. AFTER BREAK-IN FLIGHT AND TEST FLIGHTS, NR 2 CYL ON LT ENGINE WAS NOTED TO HAVE LOW COMPRESSION: 18/80. LEAKAGE DETERMINED TO BE PAST INTAKE VALVE. REMOVAL AND DISASS
- [SDR 97ZZZX1919](https://openairdocs.org/sdr/97ZZZX1919.md): Gear · failed · Apr 22, 1997 · N6867L · Cessna 421C · Reciprocating Engine Power Section
  > NEW CRANKSHAFT GEAR P/N 653580 INSTALLED AT TIME OF ENGINE OVERHAUL IN CONJUNCTION WITH TCM SB CSB 94-4 IN KIT EQ6642. ENGINE FAILED APROXIMATELY 400.0 HOURS LATER. ENGINE DISASSEMBLY REVEALED THE POSSIBILITY THE GEAR BROKE FIRST CAUSING DAMAGE TO VALVE TRAIN
- [SDR 96ZZZX6160](https://openairdocs.org/sdr/96ZZZX6160.md): Drive Adapter · worn · Nov 16, 1996 · N749CA · Cessna 421C · Reciprocating Engine Rear Section
  > STARTER DRIVE GEAR WEAR UNACCEPTABLE IAW TELEDYNE CONTINENTAL CSB 94-4 EVEN THOUGH THE SERVICE KIT REQUIRED BY TCM CSB 94-4 HAD BEEN PREVIOUSLY INSTALLED AT THE ENGINE OVERHAUL. SUSPECT CAUSE: CSB 94-4 MAY NOT BE SUFFICIENT. SUBMITTER RECOMMENDS FLEET DATA
- [SDR AU960486](https://openairdocs.org/sdr/AU960486.md): Pipe · corroded · Apr 16, 1996 · Cessna 421C · Aircraft Fuel Distribution System
  > (AUS) LH NACELLE FUEL TANK TRANSFER PUMP TO 'T' FITTING PIPE LEAKING FUEL FROM PIN HOLE DUE TO INTERNAL CORROSION
- [SDR 96ZZZX2407](https://openairdocs.org/sdr/96ZZZX2407.md): Piston · burned · Apr 2, 1996 · N67934 · Cessna 421C · Reciprocating Engine Cylinder Section
  > AIRCRAFT LOST POWER ON NR 1 ENGINE. REMOVAL OF NR 5 CYLINDER REVEALED PISTON DOME EDGE BURNED AWAY FROM 6:00 POSITION TO 12:00 POSITION. AT 9:00 POSITION, PISTON DOME BURNED COMPLETELY THROUGH, APPROXIMATELY 1 INCH OF PISTON MATERIAL MISSING FROM EDGE TOWARD
- [SDR 96ZZZX950](https://openairdocs.org/sdr/96ZZZX950.md): Adapter Kit · excess wear · Dec 27, 1995 · N369NM · Cessna 421C · Reciprocating Engine Rear Section
  > ON 12-27-95, A 50-HOUR INSPECTION WAS PERFORMED. METAL CONTAMINATION NOTED IN RT ENG OIL FILTER. FURTHER INVESTIGATION REVEALED TORSIONAL DAMPER AND STARTER SHAFT GEAR ASSY WERE LOOSE IN THE STARTER ADAPTER HOUSING. ADAPTER ASSY REMOVED AND FND NEEDLE BEARI

Next page: https://openairdocs.org/engine/continental-gtsio-520-n/reports.md?page=2

## The whole list in SQL

Runs in DuckDB 1.2 or later on the release's Parquet files over HTTPS:

```sql
SELECT sdr_id, difficulty_date, n_number, aircraft_make, aircraft_model, part_name, part_condition, jasc_code, discrepancy
FROM 'https://openairdocs.org/data/latest/faa_service_difficulty_report.parquet'
WHERE engine_model_key = 'GTSIO520N'
ORDER BY difficulty_date DESC
```

This list as a web page: https://openairdocs.org/engine/continental-gtsio-520-n/reports

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