N557LM

ATA 7532

OPERATOR HAS EXPERIENCED A RECURRING L BLEED AIR LEAK EICAS MESSAGE ACROSS A FLEET OF FIVE LEARJET 45XR AIRCRAFT EQUIPPED WITH HONEYWELL TFE731-20BR ENGINES. THE DISCREPANCY IS INTERMITTENT AND HAS NOT BEEN REPRODUCIBLE DURING GROUND TROUBLESHOOTING, MAKING ROOT CAUSE IDENTIFICATION DIFFICULT. FOR THIS EVENT, THE DISCREPANCY OCCURRED OVER A PERIOD OF SEVERAL WEEKS. INITIAL REPORTS INDICATED THE L BLEED AIR LEAK MESSAGE WOULD ILLUMINATE INTERMITTENTLY DURING FLIGHT AND EXTINGUISH WITHOUT MAINTENANCE INTERVENTION. IN ONE OCCURRENCE, THE MESSAGE APPEARED DURING DESCENT PASSING APPROXIMATELY FL120. ADVANCING THE THRUST LEVERS CAUSED THE MESSAGE TO EXTINGUISH AND IT DID NOT REOCCUR DURING THE REMAINDER OF THE FLIGHT. MAINTENANCE ACCOMPLISHED EXTENSIVE TROUBLESHOOTING OF THE BLEED AIR LEAK DETECTION SYSTEM AND ASSOCIATED DUCTING. INSPECTIONS INCLUDED BLEED AIR PLUMBING, SENSING LINES, CONNECTORS, THERMAL BLANKETS, JOINTS, AND DUCT ASSEMBLIES THROUGHOUT THE BAGGAGE COMPARTMENT, BELLY, AND ENGINE PYLON AREAS. MULTIPLE CORRECTIVE ACTIONS WERE PERFORMED, INSPECTION, CLEANING, AND RESEATING OF BLEED AIR LEAK DETECTOR CONNECTORS. REPLACEMENT OF LP DUCT SLIP-JOINT SEALS ADJACENT TO LEAK DETECTION SENSING LINES. REPLACEMENT OF HP DUCT SEALS ADJACENT TO LEAK DETECTION SENSING LINES. REPLACEMENT OF RH LP DUCT ASSEMBLY SEALS PER LEARJET TECHNICAL SUPPORT RECOMMENDATION. REPLACEMENT OF LH ECS SHUTOFF VALVE WITH A SERVICEABLE UNIT. REPLACEMENT OF ECS CONTROLLER. INSPECTION AND TIGHTENING OF BLEED AIR LEAK DETECTION SENSING LINES. FOLLOWING EACH MAINTENANCE ACTION, GROUND RUNS AT VARYING POWER SETTINGS WERE SATISFACTORY. MULTIPLE MAINTENANCE CHECK FLIGHTS WERE CONDUCTED ATTEMPTING TO DUPLICATE THE REPORTED CONDITIONS. MOST CHECK FLIGHTS WERE SATISFACTORY AND THE AIRCRAFT WAS REPEATEDLY RETURNED TO SERVICE. HOWEVER, THE DISCREPANCY CONTINUED TO RECUR DURING SUBSEQUENT REVENUE FLIGHTS, INCLUDING BOTH CLIMB AND CRUISE PHASES OF FLIGHT. IN ONE INSTANCE, THE DISCREPANCY RETURNED APPROXIMATELY TWO DAYS AFTER MAINTENANCE ACTION; IN ANOTHER, IT OCCURRED DURING CLIMB THROUGH APPROXIMATELY 8,000 FEET MSL. THROUGHOUT THE TROUBLESHOOTING PROCESS, NO ACTUAL BLEED AIR LEAK OR OVERHEAT CONDITION COULD BE POSITIVELY IDENTIFIED. THE DISCREPANCY REMAINS INTERMITTENT AND FLIGHT-CONDITION DEPENDENT. THE INABILITY TO REPRODUCE THE EVENT ON THE GROUND HAS SIGNIFICANTLY COMPLICATED TROUBLESHOOTING EFFORTS AND RESULTED IN REPEATED AIRCRAFT DOWNTIME.

ATA 3244

UPON LANDING IN PFAI, BOTH OF THE RH TIRES HAD A BLOW OUT. THE FAILED TIRES WERE NEARLY THE SAME AS PREVIOUS ISSUES WITH THIS BRAND AND PN TIRE WE HAVE HAD NUMEROUS TIMES ON THE LR45. THE INNER AND OUTER SIDWALLS STAY WITH THE WHEEL AND THE ENTIRE TREAD SEPARATES. AS THIS IS AN ONGOING ISSUE, WE ARE DOCUMENTING DAILY TIRE CHECKS WHEN THE AIRCRAFT IS AT A MAINT BASE. THESE TIRES HAVE BEEN GOOD ON PRESSURE BETWEEN THE PRESCRIBED 160 TO 170PSI AND HAVE NOT REQUIRED VERY MUCH NITROGEN ON A WEEKLY BASIS TO STAY IN THE RANGE. THE TREAD ON ALL OF THE FAILED TIRES HAS HAD SIGNIFICANT LIFE REMAINING. IN THIS CASE, TIRE SN 20950396 HAD 261 LANDINGS ON IT AND SN 20960420 HAD 607 LANDINGS. BOTH WHEELS ARE SCRAP NOW AND ARE BEING REPLACED FOLLOWING INSPECTION OF THE MLG AND AIRFRAME AS REQUIRED. AS A SIDE NOTE, THIS AIRCRAFT ALONE HAD THE LH SIDE DUAL FAILURE SUBMITTED ON AN SDR ON 5/3/23.

ATA 3244

#1 TIRE SEPARATED ON LANDING. THIS HAS BEEN AN ONGOING ISSUE WITH GOODYEAR PN 226K08-4. DUE TO CONTINUED ISSUES WITH THESE TIRES FAILING, WE KEEP A DAILY LOG OF CONDITIONS AND PRESSURES AS MUCH AS POSSIBLE. THIS TIRE JUST HAPPENS TO HAVE BEEN CHECKED PRIOR TO DEPARTING PFAI FOR KSLC DUE TO THE #2 TIRE DEVELOPING A BULGE IN THE SIDEWALL. PRESSURE AND CONDITION WAS GOOD. THE FAILURE OF THE TIRE WAS THE ENTIRE TREAD AND SIDEWALL COMING OFF AND GETTING STUCK AGAINST THE STRUT. THE #2 HAD TO BE CHANGED DUE TO ROLLING WITH ONE FLAT PER THE AMM AS WELL AS INSPECTION OF THE MLG FOR ANY DAMAGE. #1 AND #2 WHEEL/TIRE ASSEMBLIES WERE REPLACED WITH OH UNITS AND AIRCRAFT WAS RETURNED TO SERVICE.

ATA 3244

TIRE FAILURE ON DEPARTURE FROM PFAI. NOTATED SOUND OF POSSIBLE TIRE POP ON DEPARTURE OUT OF FAIRBANKS, AK. ON LANDING IN KBFI, NOTED THE #3 TIRE HAD A SECTION MISSING FROM THE INBOARD SIDEWALL AND THERE WAS A LARGE DENT IN THE FLAP JUST AFT. TREAD ON THE TIRE WAS IN GOOD CONDITION. THIS HAS HAPPENED NUMEROUS TIMES WITH GOODYEAR TIRE PN 226K08-4. THIS TIRE, SN 11750431, HAD 367 LANDINGS ON IT WITH PLENTY OF TREAD. DAMAGE CAUSED REJECTION OF WHEEL FROM NDT AND REPLACEMENT OF FLAP AS WELL. PRIOR TO THIS INCIDENT, WE HAVE LOST 3 TIRES BLOWING OUT LIKE THIS ON THE LEAR 45'S WITH GOOD TREAD AND HAVE BEEN HYPERSENSITIVE TO CHECKING TIRE PRESSURES. WE OPERATE 5 LEAR 45'S AND HAVE HAD THE ISSUE WITH THESE TIRES ACROSS THE FLEET. THE SIDEWALLS HAVE DEVELOPED BULGES AROUND THE RADIUS AS WELL AS CRACKING. WE HAVE ALSO PROVIDED FAILED TIRES TO GOODYEAR AS WELL FOR SAMPLES TO BE TOLD THAT THEY ARE SHOWING SIGNS OF BEING UNDERSERVICED. TO DATE OVER THE PAST 12 MONTHS, WE HAVE REPLACED 20 OF THESE TIRES DUE TO LOSS OR BLISTERING IN THE SIDEWALLS. WE ARE SEEING ON AVERAGE ABOUT 300 LANDINGS BEFORE WE CHANGE DUE TO SIGNS OF BLISTERING/CRACKING ON THE SIDEWALLS. MORE INFORMATION ON THE NUMEROUS FAILURES OF THESE TIRES AVAILABLE.

ATA 2611

PILOT REPORTS POSSIBLE EVIDENCE OF SMOKE IN CABIN/COCKPIT ON TAKEOFF FROM BETHEL. REPORT FROM CREW WAS THERE WAS NO SMOKE SMELL OR BURNING SMELL ASSOCIATED. SAID IT WAS MORE OF A "GRAPHITE" SMELL/TASTE. ONCE THIS WAS NOTATED, CREW LANDED THE AIRCRAFT. MAINT PERSONNEL PERFORMED GROUND RUNS FOR APPROX 45 MINS WHILE UTILIZING ANY HEAT SOURCES, ELECTRICAL LOADS (TO INCLUDE MEDICAL BEDS), AND NUMEROUS POWER SETTINGS. NO ISSUES WERE NOTED. UNABLE DO DUPLICATE ANY SMOKE LIKE SMELLS (INCLUDING GRAPHITE) OR VISUALS. AIRCRAFT WAS RELEASED FROM MAINT AND CHECK FLIGHT WAS SATISFACTORY WITH NO ISSUES. ORIGINALLY SUBMITTED: 1/7/22.

ATA 2560

ON APPROACH/LANDING IN BFI, MEDICAL CREW NOTATED A SMOKE LIKE SMELL IN THE CABIN ASSOCIATED WITH A FLICKERING LIGHT ON THE FORWARD LIFEPORT PLUS UNIT WITH A POPPED CIRCUIT BREAKER ON THE FACE OF THE LIFEPORT FOR THE SUCTION PUMP. AIRCRAFT IS EQUIPPED WITH TWO LIFEPORT PLUS UNITS. THIS TRANSPORT ALSO INCLUDED AN ISOLETTE FOR THE MISSION. AIRCRAFT LANDED WITHOUT ISSUE AND SMOKE LIKE SMELL DISSIPATED. MAINT LOOKED AT THE LIFEPORT WHILE THE ISOLATE WAS INSTALLED AND WAS ABLE TO RE-CREATE THE POPPED CIRCUIT BREAKER FOR THE FORWARD BED ALONG WITH FLICKERING LIGHTING ON THE BED. WITH THE ISOLETTE NOT INSTALLED IN THE AIRCRAFT, THE AIR AND SUCTION PUMPS OPERATED WITHOUT ANY ISSUES. THE FORWARD LIFEPORT BED WAS DEFERRED UNDER THE NEF PROGRAM AND AIRCRAFT WAS REPOSITIONED TO ANC WITHOUT ISSUE. INVESTIGATION CONTINUES ON THE LIFEPORT BED ITSELF AS WELL AS THE ISOLETTE ITSELF THAT MAY HAVE CAUSED THE ISSUE. WILL UPDATE REPORT ONCE WE HAVE COMPLETED MAINT AND DETERMINED CAUSE.

ATA 7321

IN CRUISE FLIGHT, THE FLIGHT CREW NOTICED THAT THE LH THROTTLE WAS STUCK IN THE MCR POSITION. ALL ATTEMPTS TO REDUCE THE THROTTLE WERE UNSUCCESSFUL. UPON CONSULTATION WITH THE MAINTENANCE DEPARTMENT, VIA SATELLITE PHONE, IT WAS DETERMINED THAT A LANDING AT THE NEAREST AERO AIR MAINTENANCE FACILITY WAS THE BEST OPTION. THAT FACILITY WAS IN JUNEAU, ALASKA. THE FLIGHT CREW NOTIFIED THE ANCHORAGE ARTCC THAT THEY WANTED TO DIVERT, AND FURTHER NOTIFIED THEM THAT THEY WOULD BE EXECUTING A PRECAUTIONARY ENGINE SHUT-DOWN. THE CREW DECLARED AN EMERGENCY, BECAUSE OF THE PRECAUTIONARY SHUT-DOWN, AND PROCEEDED WITH THE DESCENT AND LANDING WITH OUT FURTHER ISSUE. AIRCRAFT WAS TAKEN TO MAINT HANGAR AND DURING INVESTIGATION OF SYSTEM WAS NOTED THAT THE FCU ON THE LH ENGINE WAS JAMMED WITHOUT ANY OUTSIDE CONNECTIONS ATTACHED. INTERNAL BINDING IN THE FCU WAS THE CAUSE OF THE STUCK LEVER. LEVER AND ALL ASSOCIATED THROTTLE CABLES/QUADRANTS MOVED WITH NO ISSUES ONCE DISCONNECTED FROM FCU. FCU WAS ORDERED AND IS BEING REPLACED.