DOLPHIN ATLANTIC INC

Sanction: $18,000 · case closed 2011-01-24

Part: FLAP SYSTEM — OUT OF RIG · airframe 4,958 hrs · 3,999 cycles

FLAP FAIL CREW WAS STAGED TO LANDED ON FINAL. CONDITIONS WERE IMC, ENGINE AI AND WING STAB WAS ON. UPON SWITCHING FROM FLAPS 0 TO 1, FLAP FAIL CAS MESSAGE IMMEDIATELY APPEARED. CREW REQUESTED PUBLISHED MISSED APPROACH. CREW RAN FLAP FAIL MESSAGE AND NO CHANGES TO THE FAILURE APPEARED. CREW DIVERTED TO KSYR. NO VISIBLE DAMAGE WAS SEEN ON FLAP SURFACES UPON POST F LIGHT INSPECTION. AOG MAINTENANCE CREW COULD NOT DUPLICATE THE PROBLEM AFTER SEVERAL FLAP OPERATIONAL CHACKS. AOG CREW SWAPPED FCE 1 & 2 AND RE-RIGGED THE FLAPS AND SPOILERS. AIRCRAFT WAS RETURNED TO SERVICE.

Part: PDU — FAILED (FLAP SYS) · airframe 4,871 hrs · 3,945 cycles

ON APPROACH TO LAND AT KAPA PILOTS SELECTED FLAPS DOWN, AND FLAP SYSTEM DID NOT RESPOND. PILOTS RECEIVED A CAS MASSAGE "FLAP FAIL". CREW FOLLOWED FOM AND PROCEEDED TO MAKE AN UNEVENTFUL NO FLAPS LANDING. AN EMBRAER AOG MAINTENANCE TEAM WAS DISPATCHED TO TROUBLESHOOT THE FLAP SYSTEM MALFUNCTION AND THEY DETERMINED THE FLAP PDU POWER DRIVE UNIT. THE PDU WAS REPLACED, FLAP SYSTEM RIGGED AND OPERATIONALLY CHECKED. AIRCRAFT WAS RETURNED TO SERVICE WITH NO FURTHER REOCCURRENCES ON SEVERAL SUBSEQUENT FLIGHTS TO DATE.

Part: CONTROL LEVER — FAULTED (COCKPIT) · airframe 6,118 hrs · 4,275 cycles

ON APPROACH TO LAND AT KAPF THE FLAPS FAILED TO LOWER. AIRCRAFT MADE AN UN-EVENTFUL LANDING W/O FLAP USE. FLAP SYSTEM WAS TROUBLESHOT AND THE FLAP HANDLE CONTROL ASSEMBLY WAS DETERMINED TO BE FAULTY. THE FLAP HANDLE CONTROL ASSEMBLY WAS REPLACED AND THE AIRCRAFT WAS RETURNED TO SERVICE. NO FURTHER INSTANCES OF ANY FLAP ISSUE HAS BEEN REPORTED SINCE THE INITIAL FAILURE AND REPLACEMENT

Part: UNKNOWN — UNKNOWN (UNKNOWN) · airframe 1,889 hrs · 1,174 cycles

HYDRAULIC SYSTEM FAILURE. DURING APPROACH TO LAND WHILE EXTENDING THE LANDING GEAR, THE MAIN LANDING GEAR DID NOT SECURE FOLLOWED BY THE CAS MESSAGE LG LEVER DISAG, APPROPRIATE QRH PROCEDURE ACCOMPLISHED AND THE LANDING GEAR WAS RECYCLED DOWN AND LOCKED, THEN THE FOLLOWING CAS PRESENTED IN SEQUENCE HYD LO PRESS, PUSHER FAIL, BRK FAIL. HYD PRESS ON SYNOPTIC PAGE INDICATED 0 PSI, QRH PROCEDURES COMPLETED FOR ALL CAS PREVIOUSLY MENTIONED AND THE AIRCRAFT LANDED BRAKING USING THE EMERGENCY/PARKING BRAKE TECHNIQUE. DURING THE LANDING ROLL, THE LEFT MAIN TIRE BLEW OUT AND THE AIRCRAFT CAME TO A FULL STOP ON THE RUNWAY. SUBSEQUENT MAINTENANCE INVESTIGATION OF THIS FAILURE FOUND LARGE HYDRAULIC FLUID LOSS AT BELLY OF THE AIRCRAFT NEAR THE HYDRAULIC POWER PACK AND RESERVOIR AREA. THE CAUSE OF THE HYDRAULIC SYSTEM LOSS WAS NOT YET KNOWN AT THE TIME OF THIS REPORT SUBMISSION.

Part: WINDSHIELD — CRACKED (COCKPIT) · airframe 4,678 hrs · 3,403 cycles

DURING LIMB, AT 15,000' PILOTS WINDSHIELD OUTER NON-STRUCTUAL GLASS SURFACE LAYER SHATTERED.

Part: VALVE — BROKEN (RAM AIR) · airframe 3,664 hrs · 2,509 cycles

RAM AIR VALVE FAILED (DOOR HINGE POINTS CRACKED/BROKEN). CREW RECEIVED A "DUCT1 OVR HT" FOLLOWED BY A "DUCT2 OVR HT" CAS MESSAGE. PER THE FLIGHT MANUAL, ENGINE POWER WAS REDUCED AND THE AIRCRAFT MADE AN UNSCHEDULED LANDING AT KBNA. AOG TEAM FOUND THE RAM AIR CONTROL VALVE BROKEN, AND REPLACED THE VALVE AND DOWNSTREAM HEAT EXCHANGER.

Part: FLAP SYSTEM — INTERMITTENT · airframe 3,063 hrs · 2,272 cycles

ON APPROACH, FLAPS CAS MESSAGE INDICATED FLAP FAIL WHEN TRANSITIONING FROM FLAP POSITION 3 TO FLAP POSITION 4. PER THE QRM, FLAPS WERE RESET, AND THEN WORKED NORMALLY TO FLAP POSITION 4. NORMAL LANDING WAS THEN MADE. ISSUE WAS REPEATED ON GROUND ONCE, IN TEST, BUT THEN CLEARED. AIRCRAFT IS CURRENTLY BEING EVALUATED FOR THE OFFENDING CAUSE. NO CAUSE YET KNOWN. THE AIRCRAFT IS GROUNDED AND AOG UNTIL CAUSE IS KNOWN, WITH A RESOLVING DISPOSITION ISSUED FROM THE MANUFACTURER (EMBRAER), AND REPAIRS MADE.

Part: FLAP SYSTEM — FALSE INDICATION · airframe 3,018 hrs · 2,242 cycles

ON APPROACH TO LAND, CREW CAS ALERTED "FLAP FAIL". AIRCRAFT MADE A 0 DEGREE FLAP LANDING WITHOUT INCIDENT. POST INSPECTION OF THE FLAP SYSTEM REVEALED NOTHING. FLAPS WORKED PERFECTLY ON THE GROUND. THE MANUFACTURERS PROCEDURES WERE FOLLOWED TO INSPECT THE SYSTEM. NO FAULT FOUND. AIRCRAFT WAS RETURNED TO SERVICE.

Part: STARTER GEN — FAILED (NR 1) · airframe 2,594 hrs · 1,969 cycles

FAILURE OF #1 GENERATOR.

Part: STARTER GEN — FAILED (NR 2 ENGINE) · airframe 2,553 hrs · 1,932 cycles

#2 ENGINE HAD A STARTER/GENERATOR FAILURE IN CRUISE. CREW MADE A SMALL DIVERSION FOR DESTINATION AIRPORT, LANDING AT KFLL INSTEAD OF ORIGINALLY INTENDED KOPF. THE REMAINER OF THE FLIGHT AFTER THE STARTER/GENERATOR FAIL WAS UNEVENTFUL.

Part: TRIM SYSTEM — FAILED (PRIMARY PITCH) · airframe 2,529 hrs · 1,915 cycles

PRIMARY PITCH TRIM FAILURE. CAUSE UNKNOWN

Part: STARTER GEN — FAILED (RT ENGINE) · airframe 1,832 hrs · 1,206 cycles

AT CRUISE, INDICATION OF LOSS OF ELECTRICAL POWER OF THE #2 DC STARTER/GENERATOR. CREW ELECTED TO MAKE AN UNSCHEDULED PRECAUTIONARY LANDING AT KATL. UPON INSPECTION, THE STARTER GENERATOR WAS DISCOVERED TO BE INTERNALLY FAILED, AND HAD SHEARED ITS DESIGNED DRIVE SHAFT SHEAR POINT. PRIOR TO IT SHEARING ITS SHAFT, THE STARTER GENERATOR SHEARED ITS QAD MOUNT DOWEL PINS AND ROTATED APPROXIMATELY 45 DEGREES ON ITS MOUNT PAD.

Part: SENSOR — FAILED (WING) · airframe 548 hrs · 454 cycles

AFTER TAKE OFF CREW RECEIVED A CAS WARNING "WING STAB" LEAK. AIRCRAFT RETURNED TO STARTING POINT AND MAINTENANCE CREWS WERE DISPATCHED FROM KFLL TO INVESTIGATE SOURCE OF THE CAS MESSAGE. IT IS BELIEVED AT THIS TIME THAT THE LEAK SENSOR ITSELF FAILED, AND NO LEAK IS SO FAR INDICATED.

Part: BEARING — FAILED (MLG WHEEL) · airframe 2,664 hrs · 1,732 cycles

WHILE TAXING FROM PARKING SPOT, CREW NOTICED NOISE COMING FROM NOSE WHEEL. RETURNED TO PARKING SPOT & THE ACFT NOSE WHEEL HAD SIGNS OF WHEEL BEARING FAILURE. SUBSEQUENT INSPECTION REVEALED THE NOSE WHEEL BEARING HAD FAILED. NOSE WHEEL TIRE ASSEMBLY SUBSEQUENTLY REPLACED BY THEIR FIELD REPAIR UNIT & ACFT WAS DISPATCHED WITHOUT FURTHER PROBLEMS. PN OF FAILED BEARING DSR 4629-1019 MALFUNCTION & DEFECT REPORT SUBMITTED.

Part: DOOR — BINDING (MLG) · airframe 2,096 hrs · 1,340 cycles

UPON EXTENDING THE LANDING GEAR FOR LANDING, ONCE THE MAIN GEARS WERE DOWN AND LOCKED INDICATING GREEN/SAFE, THE INBD GEAR DOORS FAILED TO SEQUENCE TO THE CLOSED POSITION. THE INBD GEAR DOORS SUBSEQUENTLY STAYED OPEN DURING THE LANDING AND TAXI IN, SCRAPPING ON THE PAVEMENT. THE LANDING AND TAXI IN WERE UNEVENTFUL EXCEPT FOR TH DRAGGING OF THE INBD GEAR DOORS, WHICH RESULTED IN MATERIAL LOSS OF THE FORWARD CORNERS OF THE DOORS WHERE THEY TOUCHED THE PAVEMENT. APPROXIMATLY A 3" X 3" AREA OF THE CORNER OF EACH DOOR WAS WORN OFF. CAUSE OF THE INBD GEAR DOORS NOT CLOSING IS CURRENTLY UNKNOWN AND IS UNDER INVESTIGATION. THIS WAS A PART 91 FLIGHT.

Part: DOOR — OPEN (MLG) · airframe 2,096 hrs · 1,340 cycles

UPON EXTENDING THE GEAR FOR LANDING, AFTER THE MAIN GEAR WERE DOWN & LOCKED, THE INBD MAIN GEAR DOORS FAILED TO STOW AND REMAINED OPEN DURING THE LANDING & TAXI, SCRAPING THE PAVEMENT & CAUSING DAMAGE TO THE LE CORNERS OF THE MAIN INBD GEAR DOORS. CAUSE OF THE MAIN INBD DOORS NOR SEQUENCING CLOSED AFTER MAIN GEAR EXTENSION IS NOT KNOWN AT THIS TIME & IS UNDER INVESTIGATION. APPROX A 3" X 3" AREA OF THE LE CORNER OF BOTH MAIN GEAR INBD GEARS DOORS WAS WORN OFF WHERE THE DOORS CONTACTED THE PAVEMENT. THE LANDING & TAXI WERE UNEVENTFUL EXCEPT FOR THE WEAR NOTED ON BOTH INBD DOORS.

Part: UPLOCK SWITCH — FAILED (LT MLG)

DEPARTING, UPON RETRACTING THE MLG, THE LT INBD GEAR DOOR DID NOT INDICATE IT HAD CLOSED & STOWED. CREW ELECTED TO RETURN TO THE AIRPORT TO INVESTIGATE. SUBSEQUENTLY, THE INBD GEAR DOOR UP SWITCH WAS DETERMINED TO BE DEFECTIVE & WAS REPLACED WITH A NEW SWITCH BY MOBILE SERVICE PERSONNEL & ACFT WAS RETURNED TO SERVICE WITHOUT FURTHER OCCURRENCES.

Part: STEERING SYS — MALFUNCTIONED (NLG) · airframe 6,884 hrs · 5,511 cycles

UPON TAKING THE RUNWAY FOR DEPARTURE, CREW NOTICED THAT THE NOSE WHEEL STEERING HAD DISENGAGED. ACFT TAXIED BACK. MX EVALUATION, NWS OPERATIONALLY CHECKED GOOD IAW MM PROCEDURES. ACFT SUBSEQUENTLY OPERATED 8 LEG SEGMENTS WITHOUT FAULT. UPON LANDING, DURING ROLL OUT, NOSE WHEEL STEERING FOUND INOPERATIVE. NWS OPERATIONALLY CHECKED GOOD IAW MFG MM PROCEDURES. IAW FIELD SUPPORT RECOMMENDATIONS, ALL NWS WIRING WAS LOAD TESTED WITH NO FAULT FOUND. NWS COMPUTER WAS REPLACED AS A PRECAUTIONARY MEASURE AS THE MOST LIKELY COMPONENT CAUSE OF THE REPORTED BUT NOT DUPLICATED INOPERATIVE CONDITION.

Part: CONTROL MODULE — INOPERATIVE (COCKPIT) · airframe 134 hrs · 87 cycles

AIRCRAFT FAILED TO PRESSURIZE AFTER TAKEOFF.

Part: DUCT — UNSERVICEABLE (LT NACELLE) · airframe 2,490 hrs · 2,670 cycles

LEFT BLEED AIR FAIL WARNING LIGHT ILLUMINATED IN FLIGHT. RETURNED TO AIRPORT WITH LT BLEED AIR TURNED OFF IAW POH. NO BLEED LEAK WAS FOUND & THE WARNING SYS WAS RESTORED. ON A SECOND OCCASION, 1.5 FLIGHT HOURS LATER, WHILE ON THE GND DURING TAXI IN FROM A FLIGHT A BLEED AIR FAIL WAS AGAIN DETECTED. PILOT FOLLOWED POH PROCEDURE & SHUT OFF LT BLEED AIR. MX INVESTIGATED THE BLEED FAIL & FOUND THAT THE BLEED FAIL SYS HAD TRIGGERED IN THE AFT SECTION OF THE LT ENG NACELLE, BUT NO APPARENT BLEED LEAK COULD VISUALLY BE DETECTED IN THE GENERAL AREA. THE ADJACENT BLEED AIR DUCTING IS WRAPPED IN FOIL & FIBERGLASS INSULATION FOR THERMAL PROTECTION OF THE SURROUNDING STRUCTURE & CANNOT EASILY BE INSPECTED WITHOUT REMOVING ALL THE TUBING & OVER WRAP. THE ENTIRE BLEED AIR DUCTING OF THE LT ENG NACELLE TO THE COOLER WAS THEN REMOVED, UNWRAPPED & DETAILED INSPECTED WHICH REVEALED SMALL BLEED LEAKS AT THE DUCT COUPLINGS DUE TO LOOSE WORM CLAMPS WHICH SECURE THE COUPLINGS TO THE DUCT SECTIONS. THE DUCTS WITH TIME & HEAT WILL SLIGHTLY DEFORM UNDER THE SECURING CLAMPS & CAUSE A LEAK PATH. THE SOFT ALUMINUM DUCTS ARE ALSO SUSCEPTIBLE TO INSTALLATION DAMAGE.

Part: STARTER — BROKEN (LT ENGINE) · airframe 15,258 hrs · 1,500 cycles

LT ENG FAILED TO START. FOUND THE AFT END CAP OF STARTER MOTOR COMPLETELY SEPARATED FROM STARTER MOTOR HSG, CRACKED 360 DEGREES AROUND CIRCUMFERENCE OF THE MOTOR HSG.

Part: HOSE — BROKEN (BRAKE SYSTEM) · airframe 1,918 hrs · 2,168 cycles

PILOT REPORTED LOSS OF BRAKE PRESSURE/EFFECTIVNES FOR RT SIDE BRAKE SYS DURING TAXI. FOUND BRAKE FLEX HOSE HAD PULLED COMPLETELY OUT OF SWAGGED HOSE FITTING AT THE BRAKE CALLIPER RESULTING IN COMPLETE LOSS OF BRAKE FLUID.

Part: HOSE — BROKEN (BRAKE SYSTEM) · airframe 1,881 hrs · 1,940 cycles

PILOT REPORTED LOSS OF BRAKE PRESSURE/EFFECTIVNES FOR LT SIDE BRAKE SYS DURING TAXI. FOUND BRAKE FLEX HOSE HAD PULLED COMPLETELY OUT OF SWAGGED HOSE FITTING AT THE BRAKE CALIPER RESULTING IN COMPLETE LOSS OF BRAKE FLUID.

Part: HOUSING — CRACKED (STARTER)

RT ENGINE FAILED TO START ON GROUND. FOUND REAR OF STARTER MOTOR HOUSING WITH 2 INCH X 2 INCH HOLE LOCATED AT THE BRUSH HOUSING. (K)

Part: HOSE — LOOSE (NR 2 FCU)

DURING TAKEOFF ROLL, NR 2 ENGINE LOST POWER AND ROLLED BACK TO LOW IDLE, TAKEOFF WAS ABORTED WITH NO FURTHER INCIDENT. CAUSE OF TROUBLE WAS FOUND TO BE THAT THE P2/T2 SENSOR LINE, PN 2525499 FROM PT/T2 SENSOR TO FUEL CONTROL UNIT(FCU) CAME LOOSE AND SEPARATED FROM THE P2/T2 SENSOR. IT WAS FOUND THAT THIS LINE HAS 2 90 DEGREE FITTINGS WITH PN MS27068UCL (STAMPED ON IT) INSTALLED ON BOTH ENDS OF LINE, THIS FITTING HAS A B-NUT SIDE THAT IS SAFTIED BUT THE (MALE) SIDE OF FITTING THAT SCREWS INTO HOSE HAS NO PROVISION TO ATTACH SAFETY WIRE. THIS NUT CAME LOOSE. A NEW LINE WITH SAME PN WAS INSTALLED, THIS NEW LINE DOES NOT HAVE THE MS27068-4CL FITTING. THE NEW HOSE ASSY ORDERED IS MODIFIED WHICH WOULD PREVENT THIS FROM HAPPENING.. THE MFG USES THE SAME OLD PN WITH THE NEW MODIFIED HOSE ASSY. CARRIER SAID THAT THEY DID NOT KNOW THE HOSE ASSY WAS MODIFIED UNTIL THEY RECEIVED THE NEW ASSY. MFG DID NOT ADVISE OF A MODIFICATION TO THE HOSE. (K)

Part: SWITCH — BURNED (AIR CON FAN)

PILOT REPORTED SMELL OF SMOKE IN COCKPIT, WHEN PILOT TURNED AIR CONDITION OFF AND CABIN FAN ON PRIOR TO TAKEOFF. TAXIED BACK TO MAIN, REMOVED OVERHEAD PANEL, FOUND WIRING TO AIR CONDITION/FAN SWITCH BURNED. REMOVED SWITCH, FOUND TERMINAL FOR FAN CIRCUIT LOOSE ON SWITCH. FOUND LOOSE TERMINAL, HAD MOVED AND CONTACTED OTHER TERMINAL CAUSING SHORT. (K)

Part: MOUNT — CRACKED (ENGINE)

DURING INSPECTION FOR A PILOT REPORTED ENGINE OIL LEAK, CRACKS WERE FOUND ON THE FORWARD ENGINE MOUNT. CRACKS ON BOTTOM LT CORNER ALONG WELD JOINING THE HORIZONTAL AND VERTICAL TUBE, MEASURES 2.5 INCHES AND 3.2500 INCHES IN LENGTH. CRACKS ON BOTTOM RT CORNER ALONG WELD AND ENGINE MOUNT BOSS MEASURES 1.7500 INCH AND 2 INCHES IN LENGTH. TECH SUPPORT ADVISED TO CHECK THE SHIMMY DAMPNER FOR A BROKEN ROLL PIN THAT SECURES THE PISTON TO SHAFT. SHIMMY DAMPNER DISASSEMBLED, NO DEFECTS FOUND. RECOMMEND STRONGER ENGINE MOUNT. (K)

Part: LINE — CORRODED (RT BRAKE)

PILOT REPORTED LOSS OF RIGHT SIDE BRAKE PRESSURE UPON LANDING. FOUND RT BRAKE MASTER CYLINDER EMPTY. FOUND HYDRAULIC LEAK UNDER COPILOT SIDE FLOOR. COURSE OF LEAK DUE TO CORRODED ALUMINUM BRAKE LINE, BRAKE LINE CORROSION CAUSED BY SCATT DUCT STEEL SUPPORT WIRE IN CONTACT WITH BRAKE LINE. FOUND SIMILARLY CORRODED OXYGEN LINES IN HEADLINER ON SAME AIRCRAFT LAST YEAR. SAME CAUSE. AIR DUCTS IN CONTACT WITH ALUMINUM LINES. CAREFUL INSPECTION AND REPLACEMENT OF ALUMINUM LINES THAT ARE IN CONTACT WITH SCATT TYPE AIR DUCTS.

Part: PUMP — INOPERATIVE (RT ENGINE)

PILOT REPORTED ROUGH RUNNING RT ENGINE IN FLIGHT WITH HIGH PRESSURE BOOST PUMP SELECTED ON. PILOT STATED (WITH BOOST PUMP ON ENGINE WANTED TO QUITE RUNNING. WHEN PUMP OFF ENGINE RAN NORMALLY. TROUBLESHOT FOUND THAT WITH DECK REFERENCE LINE REMOVED FROM PUMP AND BOOST PUMP ON FUEL STREAMED FROM PUMP AT DECK REFERENCE FITTING. PART OF AD 91-08-07 ADDRESSED THIS PROBLEM. RECOMMEND A LEAK CHECK ON THESE PUMPS AT 100 HOUR INSPECTION.

Part: SPEAKER — BURNED (ENTERTAINMT SYS)

PILOT NOTICED SMOKE AND FIRE IN CABIN DURING CLIMBOUT. PILOT DECLARED EMERGENCY, SHUT OFF ALL ELECTRIC POWER AND LANDED AIRCRAFT, WITHOUT FURTHER INCIDENT, NO PASSENGERS ON BOARD. FOUND PASSENGER ENTERTAINMENT SPEAKER LOCATED RIGHT SIDE PAX CABIN AT STATION 209, BURNED OUT. FIRE DAMAGE TO SURROUNDING INTERIOR PANEL FABRIC APPROX 12 SQ INCHES AND ADJACENT PAX SEAT CUSHION. FOUND NO CIRCUIT PROTECTION DEVICES TRIPPED. FOUND 24 VOLTS TO ONE SIDE OF DAMAGED SPEAKER. INSPECTED ENTIRE CIRCUIT WIRING , NO DEFECTS FOUND. ALL OTHER AIRCRAFT ELECTRIC SYSTEMS FUNCTION CHECK, OK. FAILURE OF THE SPEAKER AMP TO ALLOW 24 VOLTS TO SPEAKERS ALL EQUIPMENT HAS BEEN REMOVED AND WILL BE SENT TO MANUFACTURER FOR EVALUATION.

Part: LINE — CORRODED (OXYGEN SUPPLY)

WHILE PERFORMING AN OXYGEN SYSTEM FUNCTION CHECK A OXYGEN LEAK WAS DETECTED BETWEEN THE TWO LEFT SIDE PASSENGER OVERHEAD (O2) OUTLETS. A SMALL HOLE WAS FOUND IN (O2) LINE. THIS HOLE WAS A RESULT OF DISSIMILAR METAL CORROSION BETWEEN THE ALUMINUM (O2) LINE AND THE STEEL SUPPORT SPRINGS OF THE PASSENGER VENTILATION DUCT. UPON FURTHER INSPECTION CORROSION HAD DEVELOPED ON OTHER (O2) SUPPLY LINES WERE THESE LINES ARE IN CONTACT WITH THE VENTILATION DUCTS.

Part: WHEEL HALF — CRACKED (MLG)

PERFORMED DRY PENETRANT INSPECTION ON WHEEL HALVES PER BF GOODRICH MM, PARA 2 PAGE 501 REV 1/86. FOUND CRACK STARTING INSIDE TIE BOLT-HOLE EXTENDING OUTWARD IN TWO DIRECTIONS PAST THE WHEEL HALF PACKING GROOVE. CRACK WAS FOUND IN ONE TIE-BOLT HOLE ONLY. ALL TIE-BOLT HOLES HAD CORROSION PITS AROUND SURFACE (INSIDE, MATING SURFACE). CRACK MAY HAVE BEEN DUE TO AGE, PERHAPS WHEEL HALVES SHOULD BE LIFE-LIMITED OR MANDATORY NDI AT CERTAIN HOUR INTERVALS.

Part: CYLINDER — HOLE (HEAD NR 1 CYL)

DURING AN APPROACH TO LANDING, PILOT REPORTED A VIBRATION IN THE LEFT ENGINE AND OIL LEAKING FROM THE COWLING. HE PERFORMED A PRECAUTIONARY SHUT DOWN AND MADE AN UNEVENTFUL LANDING. INSPECTION REVEALED A HOLE IN NR 1 CYLINDER UNDER THE INTAKE PUSHROD HOUSING. THE HOLE ALLOWED EXHAUST GASSES TO BURN A HOLE IN THE HOUSING ALLOWING OIL LEAKAGE. SUSPECT PROBLEM MAY HAVE BEEN CAUSED BY A POOR WELD.