500/​690Aero · Twin Commander

Parts most often named Crankshaft (6) · Crankcase (5) · Bearing (4) · Stud (3)

PILOT HAD LOSS OF OIL PRESSURE ON LT ENGINE AND SHUT ENGINE DOWN AND LANDED AS SOON AS PRACTICAL. A CRACK WAS FOUND ON THE CRANKCASE AT THE TOP FWD STUD HOLE OF THE NR 2 CYLINDER BASE STUD LEADING TO AN OIL GALLEY. NEARLY ALL THE OIL HAD LEAKED OUT.

LT ENG STARTED LOSING RPM. PILOT REPORTED FUEL PRESSURE DROPPED BELOW NORMAL RANGE BUT HAVE TO BELIEVE IT WAS OIL PRESSURE. ENG WAS CAGED AND LANDED SAFELY. THE OIL PRESSURE SCREEN WAS FULL OF ALUMINUM RESTRICTING OIL FLOW TO THE ENG. ON TEARDOWN, THE NR 4 CYL WRIST PIN PLUG WAS BALLED UP TO ABOUT HALF ITS NORMAL SIZE AND THE REMAINING METAL WAS FLUSHED THRU THE ENG AND INTO THE OIL SCREENS.

CUSTOMER WAS ENROUTE TO MAINTENANCE SHOP TO GET ANNUAL INSPECTION, BOTH ENGINES OVERHAULED. RT ENGINE CYLINDER NR 2 CONNECTING ROD BROKE AT THE CRANKSHAFT ATTACHMENT CAUSING MAJOR DAMAGE TO THE CAMSHAFT, AND CRANKCASE BREAKING OPEN IN SEVERAL PLACES AROUND THE FRONT PART OF THE ENGINES. (K)

Parts most often named Windshield (20) · Window (5) · Seal (1) · Windscreen (1)

(CAN) DURING CRUISE THE LH WINDSHIELD CRACKED, PRESSURIZATION DIFFERENTIAL WAS REDUCED AND THE REST OF THE FLIGHT WAS UNEVENTFUL. (TC# 20190531010)

(CAN) DURING CRUISE, STRANGE NOISE COMING FROM THE LT OVERHEAD PANEL. NO ABNORMAL CONTROL RESPONSES. ELECTED TO DIVERT TO NEAREST AIRPORT. MX DISCOVERED A 4-5 INCH SECTION OF LT WINDOW SEALANT HAD COME LOOSE AND WAS SLAPPING ON THE TOP OF THE CABIN. TRIM REPAIRED, FLIGHT CARRIED ON.

(CAN) ACFT WAS ON A MEDEVAC FLIGHT AT NIGHT AT CRUISE ALTITUDE OF 16000 FT WHEN THE FLIGHT CREW HEARD A NOISE LIKE A SLAP. THEY COULD SEE THEN THAT THE RT WINDSHIELD WAS CRACKED. ACFT RETURNED WITHOUT FURTHER INCIDENT. INSP FOUND THE WINDSHIELD OUTER PANEL HAD SHATTERED. WINDSHIELD IS BEING RETURNED FOR INSP AND WARRANTY CONSIDERATION. WINDSHIELD REMOVED FROM ACFT AND STRUCTURE INSPECTED. NO DEFECTS FOUND.

Parts most often named Drag Brace (5) · Clevis (3) · Bolt (2) · Roll Pin (2)

LEFT MAIN LANDING GEAR WOULD NOT FULLY RETRACT AND EXTENDED SLOWLY. THE CLEVIS HAD BROKEN CAUSING ONLY THE AUXILIARY ACTUATOR TO BE FUNCTIONING.

(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 IS THE SECOND OCCURRENCE OF A PISTON FOUND CRACKED IN OUR FLEET OF 4 TWIN COMMANDERS (TC NR 20091215006)

PILOT REPORTED THE NOSE LANDING GEAR COLLAPSED ON LANDING. CAUSE WAS NOTED TO BE RELATED TO DAMAGE IN THE OVERCENTER DRAGBRACE MOUNTING AREA DUE TO THE AIRCRAFT BY PERSONS TOWING IT WHILE ON THE GROUND. THIS LOOSENED MOUNTING RIVETS, THE DRAGBRACE FITTING AND TUNNEL AREA SKINS WHICH AFFECTED THE ADJUSTMENT OF THE GEAR DOWN ASSIST SPRING, ALLOWING THE GEAR TO RETRACT WHEN THE AIRCRAFT TOUCHED THE GROUND DUE TO INSUFFICIENT DOWNLOCK PRESSURE. (K)

Parts most often named Cylinder (13) · Stud (2) · Spark Plug (1) · Cylinder Head (1)

LEFT ENGINE PILOT NOTICED PARTIAL POWER LOSS. AFTER LANDING THERE WAS A LARGE OIL LEAK FROM THE NR 6 EXHAUST PUSHROD TUBE WHICH HAD BEEN JARRED LOOSE AND UNCLIPPED. THE CAM FOLLOWER WAS BROKEN. THE TANG ON THE ROCKER COVER THAT HOLDS THE EXHAUST ROCKER SHAFT IN WAS BROKEN POSSIBLY LODGING IN THE VALVE SPRING CAUSE EXCESSIVE VALVE LASH.

LEFT ENGINE WAS LOSING RPM. WHEN RPM GOT BELOW 2000 THE PILOT FEATHERED THE ENGINE AND LANDED SAFELY. AT ENGINE TEAR DOWN THE NR 5 CYLINDER EXHAUST SEAT HAD COME LOOSE IN THE HEAD AND CAUSE ALUMINUM SHAVINGS TO GET IN THE OIL SYSTEM AND BLOCK THE PROP GOVERNOR. PROBABLE CAUSE WAS A SUDDEN COOL DOWN OF THE ENGINE AT SOME POINT.

NR 3 CYLINDER ON LT ENGINE HOLD DOWN STUDS BROKE OFF ON UPPER FWD AND LOWER FWD. ONLY ONE NUT WAS TIGHT ENOUGH TO USE A WRENCH. THE OTHER NUTS WERE LOOSE. AFTER CYLINDER REMOVAL A PIECE OF THE CASE HALF CAME OFF WITH THE CYLINDER APPROX. 6 INCHES ACROSS ALONG THE TOP OF THE CYLINDER. EXHAUST PIPE FOR THE NR3 CYLINDER BROKE OFF AT THE FLANGE.

Parts most often named Control Cable (11) · Bracket (3) · Pulley Bracket (2) · Fitting (1)

DURING LEVEL FLIGHT AT 10,000 FEET, AND SPEED OF APPROXIMATELY 180 KIAS, THE "CONTROL LOCK ON" CAS MESSAGE ILLUMINATED ON THE PFD'S. THE CONTROL LOCK LEVER WAS CHECKED TO BE IN THE UNLOCKED DETENT . AFTER MOVING THE LEVER SLIGHTLY, AND FIRMLY RETURNING IT TO THE UNLOCKED POSITION, THE CAS MESSAGE EXTINGUISHED. SUB: INSPECTED CONTROL LOCK SYSTEM AND PERFORMED CONTROL LOCK SYSTEM FUNCTIONAL TEST. NO DEFECTS NOTED AT THIS TIME. WORK DONE IN REF TO MODEL 680A MAINTENANCE MANUAL CHAPTER 27-70-00-5

LEFT AND RIGHT FORWARD RUDDER CABLES HAD BROKEN WIRE STRANDS AT LEFT AND RIGHT PULLEY AT BS 99.00. FOUND DURING 100-HOUR INSPECTION. ROTATED CABLES 10 DEGREES FROM PULLEY TO SEE BROKEN WIRE STRANDS. CAUSE, DETERIORATION DUE TO TIME. AIRCRAFT TT: 5,313 HOURS. REPLACED CABLE ASSY. (LEFT FROM RUDDER PEDAL AFT TO TURNBARREL AT STA 335.00) AND (RIGHT FROM RUDDER PEDAL AFT TO TURNBARREL AT STA 353.00).

(CAN) ON INSPECTION BOTH LT AND RT RUDDER PULLEY BRACKETS WERE FOUND CRACKED AT THE TOP PORTION. PULLEY BRACKETS WERE PATCHED USING THICKER ALUMINUM. FURTHER INSPECTIONS FOUND TWO OTHER PULLEY BRACKETS CRACKED IN THE SAME LOCATION.

Parts most often named Blade (14) · Clamp (3) · Bearing (2)

INSPECTION FOUND PROPELLER BLADE BUTT CRACKED. PROBLEM IS COVERED UNDER AD NR 68-19-04. AIRCRAFT HAS IO720 ENGINE STC.

(AUS) PROPELLER BLADE CRACKED. CRACK ORIGINATED FROM A NICK IN THE BLADE LOCATED APPROXIMATELY 76.2MM (3IN) FROM THE BLADE TIP.CRACK LENGTH 12.7MM (0.5IN). SUSPECT THE CRACK WAS INITIATED BY A PIECE OF METAL WIRE WHICH WAS FOUND IN THE BLADE DURING DRESSING OUT OF THE CRACK.

BLADE CRACK FOUND WITH EDDY CURRENT. WOULD NOT SHOW UP WITH DYE CHECK. SUBMITTER SUGGESTS REVISING AD 68-19-04 AND AD 68-13-02 TO MAKE EDDY CURRENT MANDATORY.

Parts most often named Magneto (9) · Wire (3) · Capacitor (2) · Coil (2)

THE PILOT WAS UNABLE TO RETARD THE RT THROTTLE TO SLOW DOWN ON DESCENT FOR LANDING. SHUTDOWN AND FEATHERED ENG. WAS UNABLE TO TAXI ALL THE WAY INTO THE RAMP DUE TO DIFFICULTY STEERING WITH ONLY ONE ENG. RT MAGNETO COOLING FITTING PN 2610338 CAME OUT OF THE NW22WS-4-52-4 COOLING HOSE AND FELL DOWN BEHIND THE THROTTLE BELLCRANK ON THE FIREWALL. THIS WOULD NOT ALLOW FOR THE THROTTLE TO BE RETARDED. THE FITTING WAS REINSTALLED AND ACFT RETURNED TO [S/N removed].

ENGINE WAS GETTING HARD TO START, CHECKED MAG TIMING AND FOUND LT MAG TIMING OUT OF LIMITS, DISASSEMBLED MAG AND FOUND THE CAM WORN OUT . 100.3 HRS SINCE NEW

(CAN) DURING A ROUTINE COMPANY FLIGHT, THE NR 1 ENGINE STARTED RUNNING ROUGH. THE AIRCRAFT LANDED AND CALLED MAINTENANCE. UPON INSPECTION THE LT MAG WAS FOUND SEPARATED IN TWO, THE REAR HALF WAS STILL BOLTED TO THE ENGINE PAD AND THE FRONT HALF WAS HANGING BY THE IGNITION LEADS. THE MAG WAS REPLACED AND TIMED WITH THE AIRCRAFT AND RETURNED TO [S/N removed].

Parts most often named Line (7) · B-Nut (2) · Accumulator (1) · Switch (1)

(CAN) LARGE PUDDLE OF HYDRAULIC FLUID FOUND ON WALK-AROUND INSPECTION OF AIRCRAFT. HYDRAULIC RESERVOIR FOUND OVERFULL AND HYDRAULIC ACCUMULATOR FOUND DISCHARGED TO 400 PSI FROM 600 PSI. HYDRAULIC ACCUMULATOR REPLACED AS PART OF HYDRAULIC PRESSURE REGULATOR ASSEMBLY P/N EA1563 (TC# 20190605009)

LEFT ENGINE HYDRAULIC LINE BETWEEN ENGINE HYD PUMP AND FIREWALL. FITTING AT THE FIREWALL LOOSENED UP AND LEAKED HYD FLUID TO THE POINT THE PILOT GOT A HYP PRESS LOW LIGHT. PILOT DECLARED AND EMERGENCY AND LANDED WITHOUT INCIDENT.

(CAN) WHILE FIXING THE HYDRAULIC PUMP ON NR 2 ENGINE, THE PRESSURE LINE FLARE FITTING FROM PUMP TO THE FIRE WALL WAS FOUND CRACKED. NR 2 ENGINE AT FLARE ON LINE.

Parts most often named Bearing (2) · O-Ring (2) · Axle (2) · Pin (2)

LH MLG OTB AXLE FOUND TO HAVE MINOR CHIP DAMAGE. FOUND DURING OTB WHEEL AND TIRE REMOVAL AND REPLACEMENT ORDER. ACCOMPLISHEDTEXTRON AVIATION ENGINEERING MEMO DQ34412 DATED APRIL 15, 2022; 680A-0113, [tail no. removed], REPAIR RECOMMENDATION. MINOR REPAIR OF NICK ON LEFT MAIN LANDING GEAR AXLE.

LEFT MAIN GEAR STRUT WAS FLAT, TRIED TO [S/N removed], WHEN WE APPLIED NITROGEN PRESSURE HYDRAULIC FLUID CAME OUT OF A 3 INCH LONG CRACK IN THE STRUT BODY AND BEARING ASSY. AFTER TALKING WITH MFG THEY HAVE NEVER SEEN THIS TYPE OF FAILURE BEFORE.

O-RING IN THE LT MLG RETRACT CYLINDER FAILED WHICH ALLOWED THE HYD SYS OIL TO DRAIN. O-RING WAS MOST LIKELY DAMAGED DURING INSTALLATION. DURING INSTALLATION OF THIS PART O-RING LUBE OR HYDRAULIC OIL MUST BE USED TO KEEP UNIT FROM BEING DAMAGED.

Parts most often named Pin (4) · O-Ring (4) · Clevis (2) · Cylinder (1)

PILOT NOTICED HYDRAULIC FLUID ON THE RIGHT HAND MAIN LANDING GEAR AUXILIARY RETRACTION CYLINDER SHAFT. UPON DISASSEMBLY OF THE RETRACT CYLINDER THE SHAFT O-RING HAD A SMALL TEAR IN IT. AFTER O-RINGS AND BACKUP RINGS WERE REPLACED THE AIRCRAFT WAS PUT ON JACKS, GEAR RETRACTIONS AND EMERGENCY EXTENSION CHECKS WERE ACCOMPLISHED WITH OPERATIONS FOUND TO NORMAL AND NO LEAKS WERE NOTED.

(CAN) AN INTERNAL O-RING FAILURE WAS THE CAUSE OF AN ACTUATOR LEAK AND SUBSTANTIAL AIRFRAME SYS HYDRAULIC FLUID LOSS DURING FLIGHT. UPON INVESTIGATION BY MAINTENANCE CREW IT WAS DISCOVERED THAT AN INTERNAL O-RING IN THE HYDRAULIC RETRACTION ACTUATOR HAD ROLLED OUT OF POSITION WITH FRICTION FROM THE INTERNAL PART OF ITS CHROME STRUT AND EVENTUALLY FAILED.

INTERNAL FAILURE OF RT MLG ACTUATOR CAUSED TOTAL HYDRAULIC FLUID DEPLETION WITH SUBSEQUENT EMERGENCY EXTENSION OF LANDING GEAR WITHOUT INCIDENT. ACTUATOR WAS RECEIVED NEW. ASSEMBLY DATE IS 1/90. INSTALLED 10-9-96. TSN IS 7.4 AND 3 LANDINGS. OZONE INDUSTRIES, INC.