N737KA
Registered owner: BANK OF UTAH TRUSTEE, UT (owner ≠ operator)
Operators of this aircraft
Who operated this tail, and how firmly we know it.
No operator established for this aircraft.
Accident & incident history
Maintenance disclosures
THE LEFT AIR CONDITIONING BLEED AIR VALVE CIRCUIT BREAKER IS POPPING. FOUND THE 3 O'CLOCK STRUT WIRE HARNESS THAT CONNECTS TO THE BLEED AIR VALVE SHORTED. REPLACED THE WIRE HARNESS AND OPERATIONAL CHECK NORMAL.
10EA VARIABLE STATOR VANE SECOND STAGE ACTUATOR BUSHINGS FOUND MISSING OR BROKEN ON ENGINE. ENGINE REMOVED AND SENT TO SHOP.
ENGINE WOULD AUTO SHUTDOWN WHEN POWER LEVER WAS ADVANCED PAST IDLE. VSV UNISON RINGS AND LEVER ARMS WERE INSPECTED. MULTIPLE LEVER ARMS WERE FOUND DISCONNECTED FROM THE STAGE 2 UNISON RING AS WELL AS SOME ARMS WERE BROKEN. SUSPECT UNISON RING BROKE AND REPOSITIONED ITSELF TO DISENGAGE SOME VSV ARMS AS WELL AS BREAKING SOME VSV ARMS. ENGINE WILL HAVE TO BE REMOVED AND SENT TO SHOP FOR REPAIR.
BITE CHECK OF THE CABIN TEMPERATURE CONTROLLER INDICATED AN INTERNAL FAILURE OF THE CONTROLLER. REPLACED THE CABIN TEMPERATURE CONTROLLER AND OPERATIONAL CHECK NORMAL.
ON GROUND, PACKS DO NOT DELIVER COLD AIR DISCREPANCY WAS WRITTEN BY FLIGHT CREW. TROUBLESHOOTING DETERMINED THE AIR CONDITIONING ACCESSORY UNIT (ACAU) TO BE INTERMITTENT OR FAILED INTERNALLY. REPLACED THE ACAU AND OPERATIONAL CHECK NORMAL.
LEFT PACK OUTPUT TEMPERATURE APPEARS TO BE WARMER THAN THE RIGHT PACK ON THE GROUND. PERFORMED BITE CHECK ON THE CABIN TEMPERATURE CONTROLLER PER THE FIM WITH NO FAULTS DISPLAYED. PERFORMED BITE CHECK OF LEFT AND RIGHT 35 DEG CONTROLLERS. CONTROLLER FAULT WAS DISPLAYED ON THE LEFT CONTROLLER. REPLACED LEFT 35 DEG CONTROLLER. OPERATIONAL CHECK NORMAL.
THE NR 2 SOURCE OFF/ GENERATOR OFF LIGHT CAME ON IN CLIMB AND WOULD NOT RESET. ON THE GROUND, THE GENERATOR CONTROL UNIT SHOWED AN IDG FAULT LIGHT. RESET THE GCU AND PERFORMED AN ENGINE RUN WITH NO FAULTS RECURRING ON THE GCU. WHILE PERFORMING AN INSPECTION OF THE IDG, FOUND THE DIFFERENTIAL PRESSURE INDICATOR POPPED. INSPECTED THE IDG FILTER AND FOUND NO DEFECTS. EACH TIME THE DPI WAS RESET AND THEN AN ENGINE RUN WAS PERFORMED THE DPI WOULD POP IN A FEW MINUTES. REMOVED AND REPLACED THE IDG. OPERATIONAL CHECKS NORMAL.
RIGHT ENGINE DRIVE LIGHT ILLUMINATED AT ENGINE START. USING THE FAULT ISOLATION MANUAL, DETERMINED RIGHT IDG TO HAVE AN INTERNAL FAULT THAT CAUSED AN AUTOMATIC DISCONNECT. REPLACED THE IDG AND OPERATIONAL CHECKED NORMAL.
RIGHT PACK LIGHT ILLUMINATED DURING RECALL TEST DURING DESCENT INTO OAKLAND. PERFORMED BITE CHECK ON RIGHT PACK/ZONE TEMPERATURE CONTROLLER PER FIM 21-61 TASK 801. FOUND RAM AIR ACTUATOR, TRIM VALVE ZONE FWD, TCV AND FLIGHT DECK TRIM AIR VALVE LIGHT ILLUMINATED. INSTALLED RIGHT CONTROLLER ON THE LEFT SIDE AND FOUND SAME LIGHTS ILLUMINATED ON LEFT SIDE. WHEN LEFT CONTROLLER WAS INSTALLED ON RIGHT SIDE NO FAULT LIGHTS ILLUMINATED. INSTALLED LEFT CONTROLLER IN ITS ORIGINAL POSITION. REMOVED AND REPLACED RIGHT PACK/ZONE TEMPERATURE CONTROLLER AND PERFORMED A BITE CHECK ON BOTH PACK/ZONE TEMPERATURE CONTROLLERS. NO FAULT LIGHTS ILLUMINATED.
CORROSION WAS FOUND ON THE FORWARD SIDE OF THE RIGHT WING SPAR AT THE NR 2 FORWARD BOOST PUMP. THE CORROSION WAS LOCATED DIRECTLY ABOVE AND BELOW THE PUMP RADIATING OUT FROM THE BONDING JUMPER ATTACH POINTS. THE CORROSION WAS REMOVED, SPAR NDT'D AND REMAINING MATERIAL THICKNESS DETERMINED IN A .25 INCH GRID REF. SRM 57-20-10. UPPER AREA AFFECTED APPROX 4.5 IN X 1.5 IN. LOWER AREA AFFECTED APPROX 5.5 IN X 2.5 IN.
AMBER, AUTO FAIL, ANNUNCIATOR ON THE PRESSURIZATION PANEL ILLUMINATED IN THE COCKPIT. BITE CHECKS WERE PERFORMED ON THE PRESSURE CONTROLLERS. 1 CONTROLLER SHOWED A MESSAGE FOR AN INTERNAL FAULT. CONTROLLER WAS REPLACED AND OPS CHECK NORMAL.
DURING APU START, APU LOW OIL PRESSURE LIGHT ILLUMINATED AND APU AUTO SHUTDOWN. TROUBLESHOOTING USING THE FAULT ISOLATION MANUAL FOUND THE LOW OIL PRESSURE SWITCH FAILED. REPLACED THE SWITCH, OPS CHECK NORMAL.
LEFT ELEVATOR PITOT, AMBER ANNUNCIATION CAME ON AND ELEVATOR PITOT LT, CIRCUIT BREAKER TRIPPED. REPLACED LT ELEVATOR FEEL PITOT PROBE AND OPS CHECK NORMAL.
LANDING ALTITUDE WINDOW BLANK ON THE CABIN PRESSURIZATION CONTROL PANEL. USING THE DIM AND LIGHTS TEST, CONFIRMED CONTROL PANEL FAILED INTERNALLY. REPLACED THE PRESSURIZATION CONTROL PANEL AND OPS CHECK NORMAL.
WHILE PERFORMING CENTER FUEL TANK AUTO SHUTOFF TEST, FOUND RT CENTER FUEL TANK TEST SWITCH STICKING. REPLACED FUEL TEST PANEL P61-8 AND OPS TEST NORMAL.
UPPER AILERON PCU LEAKING FLUID FROM OUTPUT SHAFT. REPLACED AILERON PCU & NO LEAKS FOUND.
LOWER AILERON PCU LEAKING FLUID FROM OUTPUT SHAFT. REPLACED AILERON PCU & NO LEAKS FOUND.
LEFT BRAKE METERING VLV LEAKING FLUID FROM VLV BODY. REPLACED VLV & NO LEAKS FOUND.
NUMBER 2 ADF FAILED TO OPERATE & WAS TROUBLE SHOT TO THE ANTENNA. REPLACED THE ANTENNA & NR 2 ADF OPERATES CORRECTLY.
RT WING BODY OVERHEAT LIGHT ILLUMINATED. BITE CHECK OF THE COMPARTMENT OVERHEAT DETECTION CONTROL UNIT DISPLAYED FAULT CODE 64. RESISTANCE CHECKS ON SENSING ELEMENTS ASSOCIATED WITH THIS CODE WERE PERFORMED. THE RT INBD L/E ELEMENT M1269 WAS FOUND OUT OF LIMITS AND REPLACED. FAULT CODE CLEARED FROM THE CONTROL UNIT AND NO OVERHEAT LIGHT WAS DISPLAYED ON SUBSEQUENT FLIGHT.
NR 2 AUDIO PANEL SELECT, SWITCH STICKS WHEN NR 1 SELECTED. REPLACED NR 2 AUDIO PANEL AND OPS CHECK NORMAL.
AFT CARGO BAY FIRE LOOP "B" INOPERATIVE. REPLACED AFT CARGO PIT FIRE DETECTOR, OPS CHECK OK.
RT ELEVATOR FEEL PITOT HEAT LIGHT CAME ON AND THE CIRCUIT BREAKER TRIPPED. REPLACED THE ELEVATOR FEEL PITOT PROBE. OPS CHECKED NORMAL.
INTERMITTENT RT WING BODY OVERHEAT LIGHT. BITE CHECK ON THE COMPARTMENT OVERHEAT DETECTION CONTROL UNIT SHOWED FAULT CODE 64. LEAK CHECK PERFORMED ON PNEUMATIC DUCTS IN THE RIGHT WING, RIGHT PYLON AND ECS BAY WITH NO LEAKS FOUND. USING THE FIM AND AN OVERHEAT DETECTION MODULE TEST BOX FOUND SENSING ELEMENT M1764 IN THE RT WING OTBD OF THE PYLON TO BE FAILING A VOLTAGE TEST. REPLACED SENSING ELEMENT M1764 AND ALSO SENSING ELEMENT M1763. SDR COZA20150604052 FOR REPLACEMENT OF THIS ELEMENT. NO OVERHEAT LIGHT DURING SUBSEQUENT FLIGHT.
INTERMITTENT RT WING BODY OVERHEAT LIGHT. BITE CHECK ON THE COMPARTMENT OVERHEAT DETECTION CONTROL UNIT SHOWED FAULT CODE 64. LEAK CHECK PERFORMED ON PNEUMATIC DUCTS IN THE RT WING, RT PYLON AND ECS BAY WITH NO LEAKS FOUND. USING THE FIM AND OVERHEAT DETECTION MODULE TEST BOX FOUND SENSING ELEMENT M1763 IN THE RT ENGINE PYLON TO BE FAILING A VOLTAGE TEST. REPLACED SENSING ELEMENT M1763 AND ALSO SENSING ELEMENT M1764. SDR COZA20150604051 FOR REPLACEMENT OF ELEMENT M1764. NO OVERHEAT LIGHT DURING SUBSEQUENT FLIGHT.
ON DECENT, RT DUCT PRESSURE INDICATED 15 PSI WITH LT PRESSURE AT 40 PSI. BLEED TRIP LIGHT ILLUMINATED. REPLACED PRE-COOLER CONTROL VALVE SENSOR AND BLEED SYSTEM OPERATED NORMALLY.
ON DECENT, RT DUCT PRESSURE INDICATED 15 PSI WITH LT PRESSURE AT 40 PSI. BLEED TRIP LIGHT ILLUMINATED. REPLACED PRE-COOLER CONTROL VALVE AND BLEED SYSTEM OPERATED NORMALLY.
THE AUTO FUNCTION OF THE CABIN PRESS CONTROL FAILED. TROUBLESHOOTING USING THE FAULT ISOLATION MANUAL & BITE TESTS FOUND A FAULT ON THE OUTFLOW VLV. THE OUTFLOW VLV WAS REPLACED & FAULTS DID NOT RETURN. OPERATIONAL TESTS OF THE CABIN PRESS CONTROL SYS WERE NORMAL.
ON THE GND, FIRST OBSERVERS AUDIO PANEL HAD NO LIGHTS IN THE MIKE SELECTOR BUTTONS. REPLACED AUDIO PANEL & OPERATIONAL CHECKED NORMAL.
NR 2 VOR NAVIGATION PANEL INTERMITTENTLY DISPLAYED INCORRECT NUMBERS IN THE ACTIVE FREQUENCY WINDOW, THOUGH THE PANEL, WORKED CORRECTLY OTHERWISE. REPLACED THE DISPLAY AND OPS CHECK NORMAL.
LEFT FORWARD POSITION LIGHT WAS FOUND INOPERATIVE. DURING REPLACEMENT OF BULB, SOCKET WAS FOUND OXIDIZED TO WHERE REPAIR WAS NOT POSSIBLE. REPLACED THE POSITION LIGHT ASSEMBLY AND OPS CHECKED NORMAL.
NR 2 VOR NAVIGATION DISPLAY WENT BLANK. REPLACED DISPLAY AND OPS CHECK NORMAL.
WHITE MESSAGE "A/T LIM" ON UPPER DISPLAY UNIT. TAT PROBE SIGNAL FAIL MAINTENANCE MESSAGE WAS FOUND DURING TROUBLESHOOTING USING THE FIM. TAT PROBE WAS REPLACED AND SYSTEM CHECKED NORMAL.
DURING PHASE 5 INSPECTION, CENTER FUELING SHUTOFF VALVE MANUAL OVERRIDE BUTTON FOUND STIFF AND INTERMITTENT WHEN OPERATED. REPLACED VALVE, PN 2671345. OPS CHECK NORMAL.
DURING PHASE 5 INSPECTION, LEFT FUELING SHUTOFF VALVE MANUAL OVERRIDE BUTTON FOUND STIFF AND INTERMITTENT WHEN OPERATED. REPLACED VALVE, OPS CHECKED NORMAL.
ON A VERIFICATION FLIGHT, "B" SYSTEM ENGINE HYDRAULIC PUMP LOW PRESSURE LIGHT CAME ON. INSPECTION FOUND THE RT ENGINE HYDRAULIC PUMP WAS EXTREMELY HOT AND LEAKING FLUID, BUT THE SHAFT HAD NOT SHEARED. THE QUICK DISCONNECT FITTING FOR THE RT ENGINE HYD PUMP CASE DRAIN LINE WAS FOUND TO BE DEFECTIVE AND THE LINE WAS BLOCKED. THE QUICK DISCONNECT FITTING, PN 155006-09 WAS REPLACED AND THE BLOCKAGE WAS REMOVED FROM THE LINE. THE HYDRAULIC PUMP, PN 66087 WAS REPLACED, THE HYDRAULIC FILTERS WERE REPLACED AND THE ENGINE OIL FLUSHED. SUBSEQUENT OPERATIONS HAVE BEEN NORMAL.
AFTER TOP OF DESCENT, "B" HYDRAULIC SYSTEM LOW PRESSURE LIGHT CAME ON. ON GROUND, INSPECTION OF RT ENGINE FOUND HYDRAULIC FLUID ON THE ENGINE COWLING. FURTHER INVESTIGATION, FOUND THE RT ENGINE HYDRAULIC PUMP SHAFT SHEARED AND THE ENGINE OIL OVER FULL. HYDRAULIC PUMP REPLACED AND HYDRAULIC FILTERS CHANGED. ENGINE OIL SYSTEM WAS FLUSHED. DURING NEXT FLIGHT, HYDRAULIC PUMP FAILED AGAIN. PUMP SHAFT DID NOT SHEAR BUT THE PUMP OVERHEATED. FURTHER INVESTIGATION FOUND THE QUICK DISCONNECT FITTING FOR THE ENGINE HYD PUMP CASE DRAIN LINE DEFECTIVE AND BLOCKAGE IN THE CASE DRAIN LINE. QUICK DISCONNECT FITTING, PN 155006-09 WAS REPLACED AND THE BLOCKAGE WAS REMOVED FROM THE CASE DRAIN LINE. HYD PUMP, PN 66087 WAS REPLACED. HYDRAULIC FILTERS WERE CHANGED AND THE ENGINE OIL FLUSHED. SUBSEQUENT OPERATION NORMAL.
AFTER A FLAPS 40 LANDING, THE FLAPS SPLIT AND STOPPED WHILE BEING RETRACTED. THE LT FLAP SKEW SENSOR INDICATOR CIRCUIT BREAKER POPPED. TROUBLESHOOTING DETERMINED THE NR 3 FLAP SKEW SENSOR HAD FAILED. R & R THE FLAP SKEW SENSOR. OPS CHECKS WERE NORMAL.
DURING MX CHECKS IN COCKPIT, NR 2 NAV CONTROL PANEL FOUND BLINKING. "FAILED" SHOWED IN THE WINDOWS WHEN FREQUENCIES WERE TRANSFERRED. THE NAV CONTROL PANEL WAS REPLACED AND OPS CHECKED NORMAL.
DURING LT ENGINE START, LT "START VALVE OPEN" LIGHT REMAINED ILLUMINATED AFTER ENGINE START SWITCH WAS TURNED OFF. TROUBLESHOOTING IAW THE FAULT ISOLATION MANUAL, DETERMINED THE START VALVE HAD FAILED. REPLACED LT ENGINE START VALVE AND OPS CHECK NORMAL.
DURING INSPECTION, THE NR 10 FLIGHT SPOILER ACTUATOR WAS FOUND STATICALLY LEAKING FROM THE INPUT LINKAGE ASSEMBLY. OPERATING THE FLIGHT SPOILER WITH HYD POWER DID NOT CHANGE THE LEAK RATE. REPLACED ACTUATOR AND OPERATIONALLY CHECKED WITH NO LEAKS FOUND.
ON GROUND, F/O PRIMARY FLIGHT DISPLAY UNIT WENT DARK. R & R THE DISPLAY UNIT. OPS CHECKED NORMAL.
ENGINE VIBRATION INDICATIONS WENT BLANK ON SECONDARY ENGINE DISPLAY. USING TROUBLESHOOTING INFORMATION FROM THE FIM, THE AIRBORNE VIBRATION MONITORING SIGNAL CONDITIONER WAS FOUND INOPERATIVE. REPLACED THE AVM SIGNAL CONDITIONER AND ENGINE VIBRATION INDICATIONS WERE DISPLAYED CORRECTLY.
DURING GROUND CHECKS, "ELEC" LIGHT ILLUMINATED ON THE ELECTRIC METERS, BATTERY AND GALLEY POWER MODULE. BITE CHECK ON POWER MODULE P5-13 INDICATED "SPCU INOP". REPLACED THE STANDBY POWER CONTROL UNIT. OPS CHECK NORMAL AND "ELEC" LIGHT NOT ILLUMINATED.
FLIGHT DATA RECORDER "OFF" LIGHT ILLUMINATED ON THE FDR/MACH AIRSPEED WARNING PANEL, P5. USING FAULT ISOLATION MANUAL TASKS, THE FLIGHT DATA ACQUISITION UNIT WAS FOUND FAILED INTERNALLY AND UNRESPONSIVE. REPLACEMENT FDAU, PN 967-0212-002 WAS INSTALLED AND OPS CHECKS WERE NORMAL. FDR "OFF" LIGHT WAS NO LONGER ILLUMINATED ON OVERHEAD PANEL, P5.
ACFT WAS ON THE GROUND AND "ELEC" LIGHT WAS ILLUMINATED ON THE ELECTRIC METERS, BATTERY AND GALLEY POWER MODULE. BITE CHECK ON POWER MODULE P5-13, INDICATED SPCU INOP. R & R STANDBY POWER CONTROL UNIT. OPS CHECK NORMAL WITH NO MX MESSAGES OR LIGHTS.
BACKLIGHTING ON AUDIO CONTROL PANEL P/N 5145-1-64 WAS INTERMITTENT. REPLACED PANEL AND OPERATIONAL CHECK NORMAL.
RIGHT INBOARD GROUND SPOILER, OUTBOARD ACTUATOR FOUND WEEPING FLUID. REPLACED ACTUATOR. OPS AND LEAK CHECKED NORMAL.
AIRCRAFT LANDED WITH "A" HYDRUALIC SYSTEM AT 64% AND REFILL ANNUNCIATED. INSPECTION FOUND SIGNS OF FLUID INBOARD OF RIGHT WING AND RIGHT SIDE OF FUSELAGE. RESERVOIR WAS SERVICED. LEAK CHECKS WERE PERFORMED BY ACTUATING LEADING EDGES, FLAPS, SPOILERS AND AILERONS. NO LEAKS WERE FOUND. AIRCRAFT MADE RETURN TRIP WITH NO LOSS OF FLUID. SUSPECT COLD SOAKED ACTUATOR.
DURING INSPECTION, RIGHT INBOARD LEADING EDGE FLAP ACTUATOR FOUND LEAKING. REPLACED ACTUATOR P/N 382000-1001. OPERATIONAL CHECK, NO LEAKS FOUND.
CREW REPORTED "AUTO BRAKE DISARM" LIGHT CAME ON IMMEDIATELY AFTER TOUCHDOWN. A BITE CHECK WAS PERFORMED ON THE ANTI-SKID/AUTO-BRAKE CONTROL UNIT (AACU). ACTIVE MAINTENANCE MESSAGE "BOX A/B" WAS DISPLAYED. FOLLOWING THE STEPS IN THE FIM, THIS MESSAGE INDICATES AN AUTOBRAKE CARD FAILURE AND A REPLACEMENT OF THE AACU. REPLACED AACU P/N 42-935-2. PERFORMED THE BITE TEST AND NO MAINTENANCE MESSAGES APPEARED.
DURING AIRCRAFT POWER UP, FOUND CARGO FIRE DISCHARGE LIGHT ON IN COCKPIT. TROUBLESHOT SYSTEM TO INTERMITTENT PRESSURE SWITCH ON THE CARGO COMPARTMENT FIRE BOTTLE.
RIGHT MASTER CAUTION LIGHT WAS INTERMITTENT. REPLACED LIGHT ASSY P/N 088-1031-006. OPERATIONAL CHECK NORMAL.
DURING AIRCRAFT MAINTENANCE, FLIGHT RECORDER AC CIRCUIT BREAKER POPPED AND COULD NOT BE RESET. TROUBLESHOOTING DETERMINED DIGITAL FLIGHT DATA AQUISITION UNIT P/N 967-0212-002 TO BE FAILED. REPLACED UNIT AND OPERATIONAL CHECK NORMAL.
WHILE PERFORMING AD 2012-05-02 AND SB 737-78-1088 FOUND 4 EACH THRUST REVERSER COMPRESSION FITTINGS FAILED THE ELECTRICAL CONDUCTIVITY TEST. COMPRESSION FITTINGS P/N 315A2117-11 AND -12.
WHILE ACCOMPLISHING AD 2012-05-02 AND SB 737-78-1088 FOUND 6 EACH THRUST REVERSER HEAT BLANKETS WITH NUMEROUS CRACKS. BLANKETS P/N S315A213-49,-50,-51 AND -52.
WHILE PERFORMING AD 2012-05-02 AND SB 737-78-1088 FOUND 4 EACH THRUST REVERSER COMPRESSION FITTINGS FAILED THE ELECTRICAL CONDUCTIVITY TEST. COMPRESSION FITTINGS P/N 315A2118-11 AND -12.
NR 8 LEADING EDGE SLAT ACTUATOR LEAKING. REPLACED ACTUATOR P/N 381800-1005. LEAK FIXED.
SMOKE DETECTOR A1 IN FORWARD PIT WOULD NOT TEST. REPLACED SMOKE DETECTOR P/N 473597-5. OPERATIONAL CHECK NORMAL.
DURING OPS CHECKS, RAM AIR INLET DOOR ACTUATOR WAS SLOW WHEN MOVING DOOR. REPLACED ACTUATOR AND OPS CHECKED NORMAL.
DISPLAY SOURCE MESSAGE DISPLAYED IN FLIGHT AND REVERTED TO CDS FAULT ON GROUND. REPLACED DEU NR 1 P/N 4081600-930. OPERATIONAL CHECK NORMAL.
AMBER "ELEC" LIGHT DISPLAYED ON OVERHEAD P5-13 MODULE WITH A "STAT INV INOP" MESSAGE. REPLACED STATIC INVERTER P/N 1-002-0102-2090. OPERATIONAL CHECK NORMAL.
WITH AIRCRAFT POWERED ON GROUND, CDS MAINT ANNUNCIATION DISPLAYED ON PILOT/COPILOT PFD. REPLACED NR 2 DISPLAY ELECTRONIC UNIT P/N 4081600-930. OPERATIONAL CHECK NORMAL.
LEFT WING FUEL CHECK VALVE P/N 32C194-3, S/N 6118 WAS FOUND TO HAVE A BROKEN SPRING ON FLAPPER. DISCOVERED DURING WING TANK INSPECTION. CHECK VALVE WAS REPLACED.
RIGHT FORWARD WINDSHIELD OVERHEAT ANNUNCIATOR CAME ON IN CRUISE. TROUBLESHOT WINDSHIELD HEAT SYSTEM USING FAULT ISOLATION MANUAL. REPLACED WINDSHIELD HEAT CONTROLLER P/N 83000-05604. OPERATIONAL CHECK OK.
DURING INSPECTION, THE NR 8 FLIGHT SPOILER ACTUATOR WAS FOUND STATICALLY LEAKING FROM THE INPUT LINKAGE ASSEMBLY. THE FLIGHT SPOILER WAS OPERATED WITH NO CHANGE TO THE LEAK RATE. THE ACTUATOR WAS REPLACED AND OPERATIONALLY CHECKED WITH NO LEAKS FOUND. THERE WAS NO MEASURABLE FLUID LOSS FROM THE HYDRAULIC SYSTEM.
ON POSTFLIGHT, OIL WAS DISCOVERED ON THE RIGHT ENGINE COWLING. O-RING ON OIL TANK CAP WAS FOUND ROLLED. INSPECTED O-RING WITH NO DEFECTS NOTED. RESEATED O-RING AND OIL CAP. PERFORMED ENGINE RUN WITH NO LEAKS FOUND. PERFORMED ETOPS VERIFICATION FLIGHT WITH OPS NORMAL. OIL CONSUMPTION WAS FOUND TO BE 1 QUART LOWER THAN NORMAL. O-RING HAS BEEN REPLACED.
ON ACFT POWERUP, PRESSURIZATION AMBER AUTO FAIL AND GREEN ALT LIGHTS ILLUMINATED ON COCKPIT OVERHEAD. DURING SUBSEQUENT TROUBLESHOOTING NR 2 CABIN PRESSURE CONTROLLER PN 7121-19971-01AC FAILED LRU BITE CHECK. CABIN PRESSURE CONTROLLER WAS REPLACED AND SYS OPERATIONALLY CHECKED NORMAL.
RESUBMITTING SDR, NOW WITH UNIQUE CONTROL NUMBER. ON AIRCRAFT POWER UP, PRESSURIZATION AMBER AUTO FAIL AND GREEN ALT LIGHTS ILLUMINATED ON COCKPIT OVERHEAD. DURING SUBSEQUENT TROUBLESHOOTING NR 2 CABIN PRESSURE CONTROLLER P/N 7121-19971-01AC FAILED LRU BITE CHECK. CABIN PRESSURE CONTROLLER WAS REPLACED AND SYSTEM OPERATIONALLY CHECKED NORMAL.
HYD SYS "B" FLUID LOSS. UPON LANDING, CREW REPORTED A SIGNIFICANT DECREASE SYS "B" HYD QUANTITY & FLUID ON AFT FUSELAGE AND RT INBD FLAP, ESPECIALLY NR 6 FLAP CANOE. INVESTIGATION COULD NOT DETERMINE SOURCE OF FLUID & NO LEAKS WERE NOTED AT THAT TIME. NO LEAK FOUND. MFG HAS ISSUED SL 737-SL-29-095-A. CAUSE APPEARS TO BE USE OF NAS1611-XXXA CODE O-RINGS. SUBSEQUENT MFG CHANGES REQUIRE USE OF NAS1611-XXX (NO CODE) O-RINGS. EARLIER CODE A O-RINGS WERE DISCOVERED TO TAKE A SET UNDER LONG TERM COLD SOAK CONDITIONS. THIS EXPLAINS INITIAL LEAK IN AREA OF THE RT INBD SPOILER ACTUATORS AND NO LEAK PRESENT AFTER LANDING WHEN ACTUATORS WERE WARMED BY WARM FLUID AND AIR. ACFT RETURNED TO DEPARTURE, ACCOMPLISHING A VERIFICATION FLIGHT ENROUTE WITHOUT EVENT. UPON ARRIVAL, INBD RT GROUND SPOILER INBD ACTUATOR WAS REPLACED WITH A SN ACTUATOR KNOWN TO HAVE THE NAS1611-XXX O-RINGS INSTALLED. NO LEAKS WERE OBSERVED. ACFT DEPARTED, ACCOMPLISHING AN ENROUTE VERIFICATION FLIGHT SUCCESSFULLY. OTHER ACTUATORS POSSIBLY AFFECTED BY COLD SOAKED O-RINGS ARE ALL L/E SLAT ACTUATORS, STANDBY RUDDER PCU, AND THE 3 REMAINING INBD GROUND SPOILER ACTUATORS. ACCOMPLISH A RECORDS REVIEW TO DETERMINE WHICH ACTUATORS MAY STILL HAVE THE SUSPECT NAS1611-XXXA CODE O-RINGS. CONTINUE TO MONITOR FOR LEAKS IN L/E AND GROUND SPOILER ACTUATORS.
HYDRAULIC SYSTEM-B FLUID LOSS. UPON LANDING, THE CREW REPORTED A SIGNIFICANT DECREASE SYSTEM-B HYDRAULIC QUANTITY AND FLUID ON THE AFT FUSELAGE AND RIGHT INBOARD FLAP, ESPECIALLY THE NUMBER SIX FLAP CANOE. SUBSEQUENT INVESTIGATION ON THE GROUND COULD NOT POSITIVELY DETERMINE THE SOURCE OF THE FLUID AND NO LEAKS WERE NOTED AT THAT TIME. CONSIDERABLE EFFORT WAS EXPENDED TRYING TO LOCATE THE LEAK, BUT NO LEAK WAS FOUND. BOEING HAS ISSUED SERVICE LETTER 737-SL-29-095-A TITLED HYDRAULIC FLUID EXTERNAL LEAKAGE RELIABILITY IMPROVEMENTS DATED DECEMBER 22, 2010 COMBINING VARIOUS PAST NOTICES AND SERVICE LETTERS INTO ONE DOCUMENT CONCERNING HYDRAULIC LEAKS DUE TO COLD SOAKING. THE CAUSE APPEARS TO BE THE USE OF NAS1611- A CODE O-RINGS. SUBSEQUENT MANUFACTURING CHANGES REQUIRE THE USE OF NAS1611- (NO CODE) O-RINGS. THE EARLIER CODE A O-RINGS WERE DISCOVERED TO TAKE A SET UNDER LONG TERM COLD SOAK CONDITIONS. THIS EXPLAINS THE INITIAL LEAK IN THE AREA OF THE RIGHT INBOARD SPOILER ACTUATORS AND NO LEAK PRESENT AFTER LANDING WHEN THE ACTUATORS WERE WARMED BY WARM FLUID AND AIR. THE AIRCRAFT RETURNED AFTER ACCOMPLISHING A VERIFICATION FLIGHT EN ROUTE WITHOUT EVENT. UPON ARRIVAL, THE INBOARD RIGHT GROUND SPOILER INBOARD ACTUATOR WAS REPLACED WITH A SERIAL NUMBER ACTUATOR KNOWN TO HAVE THE NAS1611- O-RINGS INSTALLED. NO LEAKS WERE OBSERVED. THE AIRCRAFT DEPARTED FOR KONA ACCOMPLISHING AN EN ROUTE VERIFICATION FLIGHT SUCCESSFULLY. OTHER ACTUATORS POSSIBLY AFFECTED BY THE COLD SOAKED O-RINGS ARE ALL LEADING EDGE SLAT ACTUATORS, STANDBY RUDDER PCU, AND THE THREE REMAINING INBOARD GROUND SPOILER ACTUATORS. ACCOMPLISH A RECORDS REVIEW TO DETERMINE WHICH ACTUATORS MAY STILL HAVE THE SUSPECT NAS1611- A CODE O-RINGS. CONTINUE TO MONITOR FOR LEAKS IN LEADING EDGE AND GROUND SPOILER ACTUATORS.
ETOPS SIGNIFICANT SYSTEM: APU AUTO SHUTDOWN IN FLIGHT. LOW OIL PRESSURE LIGHT ILLUMINATED. REPLACED APU, OPS CHECK OK.
ETOPS SIGNIFICANT SYS: ACFT ROLL AFTER SPOILER/SPEEDBRAKE HANDLE SET TO FLIGHT DETENT. FOUND ACTUATOR INTERMITTENT.
LOST LEFT IRS IN FLIGHT. UNABLE REQD NAV PERF-RNP MESSAGE DISPLAYED.
LOST LEFT IRS IN FLIGHT RNP MESSAGE DISPLAYED.