ATI JET INC.

ON 6/26/2026, N924PS, CYO924 DEPARTED KLAX AND DURING CLIMB, THE CAPTAIN REPORTED THE LH ENGINE FIRE DETECT LIGHT ILLUMINATED AND THEN WENT OUT. THE CAPTAIN ELECTED TO RETURN TO LAX. ATI JET MAINTENANCE WENT TO INVESTIGATE THE ISSUE, ENGINE COWLINGS WERE OPENED AND HIGH POWER RUNS COMPLETED. NO OBVIOUS LEAKS OR DEFECTS NOTED. A FERRY PERMIT WAS ISSUED TO REPO THE AIRCRAFT TO KELP - ATI JET MAINTENANCE FACILITY. THE AIRCRAFT ARRIVED SAFELY INTO ELP WITH NO ISSUES NOTED. THE TOP AND BOTTOM ENGINE COWLINGS WERE REMOVED AND HIGH POWER RUNS COMPLETED AGAIN. A VERY SLIGHT BLEED AIR LEAK WAS FOUND DIRECTING AIR FLOW TOWARDS A TEMP SENSOR. THIS BLEED AIR LINE SEAL WAS REPLACED AND ENGINE RUN/LEAK CHECK COMPLETED. NO ISSUES NOTED. THE AIRCRAFT WAS RETURNED TO SERVICE.

ON 5/17/26, N924PS CYO924 WAS DEPARTING KFOE HEADING TO KHYI. DURING THE CLIMB OUT, THE CAPTAIN NOTICED THE RH ENGINE LOW PRESSURE LIGHT HAD ILLUMINATED. THE LIGHT ILLUMINATES AT 20 PSI. THE CAPTAIN THEN VERIFIED THE OIL PRESSURE INDICATION AT THE PRESSURE INDICATOR. HE REPORTED THE INDICATOR WAS NEAR ZERO HE SHUT THE ENGINE DOWN AND RETURNED TO KFOE. ATI JET MAINTENANCE WAS SENT TO INVESTIGATE THE ISSUE. UPON ARRIVAL, THE MAINTENANCE TECH WAS DISCUSSING THE ISSUE AND THE CAPTAIN REPORTED CHECKING THE OIL LEVEL PRIOR TO DEPARTURE, WAS DISTRACTED AND DIDN'T PROPERLY SECURE THE LATCH ON THE OIL SERVICE PORT/DIPSTICK. FOLLOWING MAINTENANCE MANUAL TROUBLE SHOOTING/TESTING PROCEDURE, THE ENGINE OIL FILTER AND CHIP DETECTOR WAS REMOVED AND INSPECTED - NO INDICATION OF ENGINE DETERIORATION OR DAMAGE WAS PRESENT. THE OIL FILTER AND AN OIL SAMPLE WAS SENT TO AVIATION LABORATORIES FOR EVALUATION. PER THE MM, THE ENGINE WAS SERVICED AND THE ENGINE ROTATED THROUGH THE GEARBOX MANUAL DRIVE ACCESS. NO DISCREPANCIES NOTED. THE ENGINE/AIRCRAFT IS CONSIDERED OUT OF SERVICE UNTIL THE OIL SAMPLE RESULTS HAVE BEEN RECEIVED AND EVALUATED BY P&W.

ON 5/17/26, N924PS CYO924 WAS DEPARTING KFOE HEADING TO KHYI. DURING THE CLIMB OUT, THE CAPTAIN NOTICED THE RH ENGINE LOW PRESSURE LIGHT HAD ILLUMINATED. THE LIGHT ILLUMINATES AT 20 PSI. THE CAPTAIN THEN VERIFIED THE OIL PRESSURE INDICATION AT THE PRESSURE INDICATOR. HE REPORTED THE INDICATOR WAS NEAR ZERO HE SHUT THE ENGINE DOWN AND RETURNED TO KFOE. ATI JET MAINTENANCE WAS SENT TO INVESTIGATE THE ISSUE. UPON ARRIVAL, THE MAINTENANCE TECH WAS DISCUSSING THE ISSUE AND THE CAPTAIN REPORTED CHECKING THE OIL LEVEL PRIOR TO DEPARTURE, WAS DISTRACTED AND DIDN'T PROPERLY SECURE THE LATCH ON THE OIL SERVICE PORT/DIPSTICK. FOLLOWING THE PRATT & WHITNEY MAINTENANCE MANUAL TROUBLE SHOOTING/TESTING PROCEDURE, THE ENGINE OIL FILTER AND CHIP DETECTOR WAS REMOVED AND INSPECTED - NO INDICATION OF ENGINE DETERIORATION OR DAMAGE WAS PRESENT. THE OIL FILTER AND AN OIL SAMPLE WAS SENT TO AVIATION LABORATORIES FOR EVALUATION. PER THE P&W MM, THE ENGINE WAS SERVICED AND THE ENGINE ROTATED THROUGH THE GEARBOX MANUAL DRIVE ACCESS. NO DISCREPANCIES NOTED. THE ENGINE/AIRCRAFT IS CONSIDERED OUT OF SERVICE UNTIL THE OIL SAMPLE RESULTS HAVE BEEN RECEIVED AND EVALUATED BY P&W.

ON 5/17/26, N924PS CYO924 WAS DEPARTING KFOE HEADING TO KHYI. DURING THE CLIMB OUT, THE CAPTAIN NOTICED THE RH ENGINE LOW PRESSURE LIGHT HAD ILLUMINATED. THE LIGHT ILLUMINATES AT 20 PSI. THE CAPTAIN THEN VERIFIED THE OIL PRESSURE INDICATION AT THE PRESSURE INDICATOR. HE REPORTED THE INDICATOR WAS NEAR ZERO HE SHUT THE ENGINE DOWN AND RETURNED TO KFOE. ATI JET MAINTENANCE WAS SENT TO INVESTIGATE THE ISSUE. UPON ARRIVAL, THE MAINTENANCE TECH WAS DISCUSSING THE ISSUE AND THE CAPTAIN REPORTED CHECKING THE OIL LEVEL PRIOR TO DEPARTURE, WAS DISTRACTED AND DIDN'T PROPERLY SECURE THE LATCH ON THE OIL SERVICE PORT/DIPSTICK. FOLLOWING THE PRATT & WHITNEY MAINTENANCE MANUAL TROUBLE SHOOTING/TESTING PROCEDURE, THE ENGINE OIL FILTER AND CHIP DETECTOR WAS REMOVED AND INSPECTED - NO INDICATION OF ENGINE DETERIORATION OR DAMAGE WAS PRESENT. THE OIL FILTER AND AN OIL SAMPLE WAS SENT TO AVIATION LABORATORIES FOR EVALUATION. PER THE P&W MM, THE ENGINE WAS SERVICED AND THE ENGINE ROTATED THROUGH THE GEARBOX MANUAL DRIVE ACCESS. NO DISCREPANCIES NOTED. THE ENGINE/AIRCRAFT IS CONSIDERED OUT OF SERVICE UNTIL THE OIL SAMPLE RESULTS HAVE BEEN RECEIVED AND EVALUATED BY P&W.

ON 5/17/26, N924PS CYO924 WAS DEPARTING KFOE HEADING TO KHYI. DURING THE CLIMB OUT, THE CAPTAIN NOTICED THE RH ENGINE LOW PRESSURE LIGHT HAD ILLUMINATED. THE LIGHT ILLUMINATES AT 20 PSI. THE CAPTAIN THEN VERIFIED THE OIL PRESSURE INDICATION AT THE PRESSURE INDICATOR. HE REPORTED THE INDICATOR WAS NEAR ZERO HE SHUT THE ENGINE DOWN AND RETURNED TO KFOE. ATI JET MAINTENANCE WAS SENT TO INVESTIGATE THE ISSUE. UPON ARRIVAL, THE MAINTENANCE TECH WAS DISCUSSING THE ISSUE AND THE CAPTAIN REPORTED CHECKING THE OIL LEVEL PRIOR TO DEPARTURE, WAS DISTRACTED AND DIDN'T PROPERLY SECURE THE LATCH ON THE OIL SERVICE PORT/DIPSTICK. FOLLOWING THE PRATT & WHITNEY MAINTENANCE MANUAL TROUBLE SHOOTING/TESTING PROCEDURE, THE ENGINE OIL FILTER AND CHIP DETECTOR WAS REMOVED AND INSPECTED - NO INDICATION OF ENGINE DETERIORATION OR DAMAGE WAS PRESENT. THE OIL FILTER AND AN OIL SAMPLE WAS SENT TO AVIATION LABORATORIES FOR EVALUATION. PER THE P&W MM, THE ENGINE WAS SERVICED AND THE ENGINE ROTATED THROUGH THE GEARBOX MANUAL DRIVE ACCESS. NO DISCREPANCIES NOTED. THE ENGINE/AIRCRAFT IS CONSIDERED OUT OF SERVICE UNTIL THE OIL SAMPLE RESULTS HAVE BEEN RECEIVED AND EVALUATED BY P&W.

AIRCRAFT DEPARTED KELP HEADING TO KAUS. ABOUT 10 MINUTES AFTER TAKEOFF, THE CAPTAIN NOTICED THE FMS SCREEN HAD GONE BLANK. ATTEMPT TOP RE POWER WAS MADE WITH NO EFFECT. THE CAPTAIN DECIDED TO RETURN TO ELP. ATI MAINTENANCE AND AVIONICS MET THE AIRCRAFT AND VERIFIED THE FMS UNIT WAS NOT POWERING BACK ON. THE UNIT WAS PULLED AND FOUND TO BE EXTREMELY HOT. AFTER COOLING THE UNIT WAS RE INSTALLED AND IT POWERED UP - COLLING FAN NEVER TURNED ON AND THE UNIT GOT HOT AGAIN. A REPLACEMENT FMS WAS INSTALLED AND WHEN POWERED UP, THE COOLING FAN IMMEDIATELY TURNED ON. IT WAS DETERMINED THAT THE TEMP SENSOR OR THE FAN WAS INOP IN THE UNIT REMOVED. THE REPLACEMENT FMS WAS LEFT POWERED UP FOR TWO HOURS WITH NO OPERATIONAL ISSUES NOTED. THE AIRCRAFT WAS THEN RETURNED TO SERVICE.

DEPARTING KAUS HEADING TO KSTL WHEN THE CREW NOTICED THE LH GENERATOR LIGHT ON AND THE AMP OUTPUT WAS ZERO. THEY ELECTED TO DIVERT INTO KELP (ATI JETS MAINTENANCE BASE). THE AIRCRAFT WAS LANDED SAFELY IN ELP, ATI MAINTENANCE MET THE AIRCRAFT AND TESTED THE GENERATOR AND DETERMINED IT HAD FAILED. A FRESH OVERHAULED UNIT WAS INSTALLED AND ENGINE RUN/GENERATOR TEST COMPLETED. ALL FUNCTIONS FOUND TO BE NORMAL. THE AIRCRAFT WAS RETURNED TO SERVICE AND HAS COMPLETED 4 FLIGHTS SINCE THE GENERATOR REPLACEMENT - NO ISSUES REPORTED.

DEPARTING KLAF HEADING TO KORD WHEN THE GOT A FLIGHT DIRECTOR FAIL MESSAGE ON THE LH PFD/MFD. THE CREW DECIDED TO RETURN TO KLAF. THE AIRCRAFT WAS LANDED SAFELY. LOCAL MAINTENANCE WAS NOT AVAILABLE SO ATI/JETVIA MAINTENANCE ARRIVED AT THE AIRCRAFT. TROUBLE SHOOTING THE ISSUE, IS WAS VERIFIED ON THE GROUND. THE ATTITUDE/HEADING REFERENCE UNITS WERE SWAPPED FOR TROUBLE SHOOTING AND THE ISSUE DID NOT FOLLOW. MAINTENANCE THEN REMOVED AND REPLACED THE DATA ACQUISITION UNIT (DAU). SYSTEM TESTS PERFORMED AND THE ISSUE WAS CORRECTED.

DEPARTED KELP, SHORTLY AFTER TAKEOFF, THE CREW NOTICED A RH ENGINE CHIP DETECTOR LIGHT ILLUMINATED. THEY DECIDED TO RETURN TO ELP. ATI/JETVIA MAINTENANCE MET THE AIRCRAFT AND VERIFIED THE CHIP DETECTOR LIGHT WAS STILL ON. THE RH ENGINE CHIP DETECTOR WAS REMOVED AND INSPECTED. SMALL SOLID CARBON DEPOSITS WERE FOUND AT THE MAGNETIC POLES OF THE DETECTOR. THE PARTICLES WERE COLLECTED. P&W TECH SUPPORT WAS NOTIFIED AND THEIR RECOMMENDATION WAS TO SEND THE PARTICLES AND AN OIL SAMPLE FOR ANALYSIS THE OIL FILTER WAS REMOVED FOR INSPECTION WITH NO CONTAMINANTS FOUND. AN OIL SAMPLE WAS COLLECTED. THE PARTICLES, FILTER AND OIL SAMPLE WERE SENT FOR ANALYSIS FOR PRECAUTIONARY PURPOSES. THE AIRCRAFT IS CURRENTLY OUT OF SERVICE UNTIL THE RESULTS ARE VERIFIED AND REVIEWED BY P&W.

ON 1/24/2026 N662AR, CYO662 WAS DEPARTING KSUA HEADING TO KNAS. DURING CLIMB, THE CAPTAIN NOTICED THE LH ENGINE OIL PRESSURE WAS FLUCTUATING. THE SCHEDULED FLIGHT WAS OVER WATER SO THE CAPTAIN ELECTED TO RETURN TO KSUA. LOCAL MAINTENANCE WAS CALLED TO INVESTIGATE THE ISSUE. ENGINE OIL LEVELS WERE CHECKED AND FOUND TO BE NORMAL. ENGINE RUNS COMPLETED WITH ALL INDICATIONS NORMAL. THE MECHANIC THEN SWAPPED OIL PRESSURE TRANSMITTERS AND RAN ENGINES AGAIN. ALL INDICATIONS WERE NORMAL. THE LH ENGINE OIL PRESSURE/TEMPERATURE INDICATOR WAS REPLACED AND ENGINE RUNS COMPLETED. ALL INDICATIONS FOUND TO BE NORMAL - NO DEFINITIVE CAUSE OF FLUCTUATION COULD BE FOUND. AIRCRAFT WAS RETURNED TO SERVICE AND HAS BEEN ON SEVEN FLIGHTS SINCE WITH NO OTHER ISSUES REPORTED.

ON 1/23/2026 N420KV CYO420 WAS DEPARTING KORL AND WHILE THE AIRCRAFT WAS CLIMBING WITH THE AUTOPILOT ENGAGED, THE CAPTAIN REPORTED THE PITCH CONTROL WAS UNSTABLE. THE CONTROL COLUMN WAS MOVING BACK AND FORTH AND WOULD STOP WHEN AUTOPILOT WAS DISENGAGED. THE TRIP CONTINUED AT A LOWER ALTITUDE WITH AP DISENGAGED AND LANDED SAFELY AT KJAX. LOCAL MAINTENANCE WAS CALLED TO TROUBLE SHOOT THE AUTO PILOT PITCH SYSTEM. IT WAS DETERMINED THAT THE PITCH SERVO WAS THE ISSUE. THE SERVO WAS REPLACED AND A GROUND TEST COMPLETED - NO DISCREPANCIES NOTED. ALL AUTOPILOT SYSTEM FUNCTIONS WERE NORMAL. A REPOSITION/TEST FLIGHT WAS COMPLETED WITH ALL AUTOPILOT FUNCTIONS REPORTED TO BE NORMAL.

ON 1/20/2026, LEAR 60 N317MP CYO317 DEPARTED KAPF HEADING TO KSUS. AS THE AIRCRAFT WAS CLIMBING, THE CAPTAIN REPORTED THE AIRCRAFT DID NOT PRESSURIZE. HE SWITCHED TO MANUAL MODE AND STILL DID NOT. HE THEN ELECTED TO DIVERT INTO KRSW. LOCAL MAINTENANCE WAS CALLED TO INVESTIGATE THE ISSUE. IT WAS DECIDED TO START WITH THE PRESSURIZATION CONTROLLER. THE UNIT WAS REPLACED AND AIRCRAFT RELOCATED TO A BETTER EQUIPPED MAINTENANCE FACILITY. ON THE SHORT FLIGHT TO KBCT, THE AIRCRAFT STILL DID NOT START THE PRESSURIZATION PROCESS. THE FLIGHT WAS SHORT ENOUGH THAT IT WAS NOT NEEDED. THE AIRCRAFT IS OUT OF SERVICE UNTIL THE ISSUE IS RESOLVED AND A VALID TEST FLIGHT IS COMPLETED.

ON SATURDAY 1/3/2026, N198HB CYO198, DEPARTED KERI HEADING TO KECP. DURING CLIMB, THE PRESSURIZATION SYSTEM DUAL BLEED AIR WARNING LIGHTS ILLUMINATED. THE CAPTAIN DECIDED TO DIVERT/RETURN TO KERI. LOCAL MAINTENANCE WAS CALLED AND ENGINE RUNS WERE COMPLETED FOR A LEAK CHECK OF THE BLEED AIR SYSTEM. SECTIONS OF THE BLEED AIR TUBES IN THE TAIL SECTION WERE IDENTIFIED WITH THE TEMP SENSOR POSITIONED VERY CLOSE TO THE BLEED AIR TUBES. THE SENSOR SECTIONS WERE RE POSITIONED COMPARING PLACEMENT TO THE REST OF THE SYSTEM AND REFERENCING THE LEARJET M.M. ENGINE RUNS WERE COMPLETED AGAIN WITH NO ISSUES REPORTED. A TEST FLIGHT WILL BE COMPLETED BEFORE IT IS RETURNED TO SERVICE FOR FINAL DETERMINATION OF CONTINUING ISSUE.

DEPARTED KIAD HEADING TO KJAX, IN FLIGHT, TRIMMING THE HORIZONTAL STABILIZER, BOTH PRIMARY AND SECONDARY TRIM WERE INTERMITTENT, EVENTUALLY BECAME INOPERATIVE. THE CREW DIVERTED AND LANDED SAFELY INTO KVQQ MAINTENANCE WAS CALLED TO INVESTIGATE THE ISSUE. NO CAUSE TO THE STAB TRIM FAILURE HAS BEEN DETERMINED. OPEN

ON 11/12/2025, N924PS DEPARTED KMAF HEADING TO KDRO. ON CLIMB THE CAPTAIN REPORTED THE PRESSURIZATION SYSTEM SEEMED LIKE THE AIRCRAFT WAS NOT PRESSURIZING. HE THEN ELECTED TO RETURN TO KMAF. THE AIRCRAFT LANDED SAFELY, ATI MAINTENANCE ARRIVED AT MAF TO TEST THE PRESSURIZATION SYSTEM, THE PRESSURE CONTROLLER HAS AN INTERROGATION FEATURE THAT WILL ILLUMINATE A FAULT LIGHT IDENTIFYING A FAULTY COMPONENT - THE TEST WAS COMPLETED AND THE CONTROLLER FAULT LIGHT ILLUMINATED. THE CONTROLLER WAS THEN REPLACED AND THE SYSTEM WAS TESTED ON THE GROUND WITH NO DISCREPANCIES NOTED. THE AIRCRAFT DEPARTED KMAF AND FLEW TO KAPA AND THEN TO KTUS WITH NO ISSUES. WHEN DEPARTING KTUS THE PRESSURIZATION SYSTEM FAULTED AGAIN WITH THE CAPTAIN RETURNING BACK TO KTUS. THE SAME INTERROGATION WAS COMPLETED AND THIS TIME THE #1 OUTFLOW VALVE FAULT LIGHT ILLUMINATED. THE PRESSURIZATION SYSTEM AUTOMATIC MODE WAS MELED AND THE AIRCRAFT WAS FLOWN TO ATI MAINTENANCE IN KELP THE NEXT MORNING. AIRCRAFT IS CURRENTLY OUT OF SERVICE FOR REPLACEMENT OF THE OUTFLOW VALVES.

DEPARTED KCPP HEADING TO KSDL. IN CRUISE ABOUT 1.5 HRS INTO FLT, CAPTAIN REPORTED DUAL BLEED LIGHTS CAME ON INDICATING A BLEED AIR LEAK IN THE TAIL SECTION. CAPTAIN REDUCED POWER & LIGHTS WENT OUT A COUPLE MINS LATER. CAME BACK ON WHEN POWER LEVERS ADVANCED. CREW DECIDED TO DIVERT TO KOKC. ACFT LANDED SAFELY IN OKC. LOCAL MAINT CALLED TO INVESTIGATE POSSIBILITY OF A BLEED AIR LEAK IN TAIL SECTION. CREW PERFORMED ENG RUNS WHILE MAINT LEAK CHECKED BLEED AIR SYS. MX FOUND A SENSE LINE B NUT HAD WORKED LOOSE BLOWING A SMALL AMOUNT OF BLEED AIR TOWARDS A TEMP SENSOR. SENSE LINE WAS RESECURED & ENG RUNS/LEAK CHECKS COMPLETED. NO OTHER LEAKS NOTED. ACFT REPOSITIONED TO KELP WITH ISSUES. BLEED AIR SYSTEM & THE LEAKING B NUT WERE INSPECTED AGAIN BY ATI MAINTENANCE WITH NO DISCREPANCIES NOTED.

ON 6/21/2025 N924 DEPARTED KEGE FLYING TO KMDW, ONCE AT CRUISE ALTITUDE, THE CAPTAIN NOTICED THE FUEL LOAD WAS STARTING TO BECOME IMBALANCED LEFT TO RIGHT. HE NOTICED THE RH FUEL STANDBY PUMP WAS ON AND WOULD NOT TURN OFF. TO PREVENT THE FUEL ISSUE FROM GETTING WORSE, THE CAPTAIN DECIDED TO DIVERT INTO KAPA. THE CAPTAIN LANDED THE AIRCRAFT SAFELY IN APA. WHEN ON THE GROUND THE CAPTAIN SHUT POWER OFF AND CALLED ATI MAINTENANCE. UPON TROUBLE SHOOTING ATTEMPT, POWERING THE AIRCRAFT UP, THE STANDBY PUMP LIGHT WAS NOW OFF. HE CYCLED THE SWITCH/PUMP SEVERAL TIMES AND ACTUATION WAS NORMAL. THE AIRCRAFT WAS FLOWN TO KELP FOR ATI MAINTENANCE TO CONTINUE TROUBLESHOOTING, THE ISSUE COULD NOT BE DUPLICATED ON THE GROUND. A NEW STARTER WAS INSTALLED WHICH IS THE FIRST COMPONENT IN THE START SEQUENCE THAT INCORPORATES A SPEED SENSOR WHICH DISENGAGES THE STARTER AND SHUTS OFF THE FUEL BOOST PUMP AFTER START. THE RH ENGINE WAS STARTED SEVERAL MORE TIMES AND THE ISSUE WAS NOT DUPLICATED.

ON 6/6/2025, N812RP DEPARTED KMAF HEADING TO KJAC, THE CAPTAIN NOTICED THE CABIN ALTITUDE INDICATION WAS FLUCTUATING. THE CONTROLLER CIRCUIT BREAKER WAS RESET AND THE INDICATOR STABILIZED. A FEW MINUTES LATER THE INDICATOR STARTED FLUCTUATING AGAIN. THE CIRCUIT BREAKER WAS RESET AGAIN BUT DID NOT CORRECT THE ISSUE THIS TIME. THE CREW DECIDED TO DIVERT DUE TO THE INDICATION OF THE CABIN ALTITUDE. THE CREW LANDED THE AIRCRAFT SAFELY AT KALS. ATI MAINTENANCE WAS NOTIFIED AND IT WAS DETERMINED SAFE TO FLY AT LOWER ALTITUDE TO REPO THE AIRCRAFT INTO KELP FOR MAINTENANCE. THE AIRCRAFT WAS FLOWN AND LANDED SAFELY IN KELP. THE ISSUE WITH THE CABIN ALTITUDE INDICATOR WAS DUPLICATED ON THE GROUND WITH ONLY BATTERIES ON. THE CABIN PRESSURE INDICATOR WAS REPLACED WITH A SERVICEABLE/TESTED UNIT. A TEST FLIGHT WAS COMPLETED WITH NO PRESSURIZATION ISSUES REPORTED. THE AIRCRAFT HAS BEEN ON SIX MORE FLIGHTS SINCE THE TEST FLIGHT - NO ISSUES ON ANY OF THOSE FLIGHTS.

ON MONDAY, 2/3/2025 N317MP WAS DEPARTING KHND TO KAUS, THE CAPTAIN REPORTED ON TAKEOFF THAT THE AIRCRAFT DID START THE PRESSURIZATION PROCESS. WITHOUT ANY TROUBLESHOOTING, THE CAPTAIN DECIDED TO RETURN TO KHND. ATI JET MAINTENANCE SPOKE TO THE CAPTAIN TO TROUBLE SHOOT THE PRESSURIZATION SYSTEM. THE SYSTEM/CONTROLLER WERE RESET AND GROUND TESTS WERE COMPLETED. ALL TESTS WERE COMPLETED WITH THE SYSTEM WORKING NORMALLY. THEY DEPARTED KHND AND COMPLETED THE INTENDED FLIGHT WITH NO OTHER ISSUES NOTED. THE AIRCRAFT HAS COMPLETED 8 MORE LEGS ALSO WITH NO ISSUES WITH THE PRESSURIZATION SYSTEM. NO DETERMINATION COULD BE MADE IF THERE WAS AN ISSUE/MALFUNCTION WITH THE PRESSURIZATION SYSTEM.

DEPARTING KLBE, THE CAPTAIN OF N420KV REPORTED THE NOSE GEAR UNSAFE LIGHT WOULD NOT EXTINGUISH WHEN THE GEAR WAS RETRACTED. THE CAPTAIN CYCLED THE GEAR AND THE LIGHT REMAINED ON. THE CAPTAIN ELECTED TO DIVERT INTO KPIT. ON DECENT INTO KPIT, THE LIGHT EXTINGUISHED. NO MAINTENANCE WAS AVAILABLE TO ADDRESS THE ISSUE, THE AIRCRAFT WAS REPOSITIONED INTO KMMU WHERE MAINTENANCE WAS AVAILABLE TO JACK THE AIRCRAFT AND SWING THE GEAR. THE AIRCRAFT DEPARTED AND THE GEAR CYCLED NORMALLY. AFTER ARRIVING AT KMMU, THE MAINTENANCE FACILITY DID NOT HAVE JACK PADS FOR A LEARJET. THEY DID LOOK INTO THE NOSE WHEEL WELL FOR ANYTHING OUT OF PLACE OR DAMAGED, NO DISCREPANCIES NOTED. THE GEAR WAS ALSO LUBED/SPRAYED. WHILE IN KLBE, THE AIRCRAFT WAS LEFT ON THE RAMP IN EXTREME COLD. IT WAS DECIDED THE COLD WEATHER EFFECTED THE FUNCTION OF THE NOSE GEAR DOOR UNSAFE LIGHT AS THE INDICATION WAS NORMAL AFTER THE TEMPS INCREASED AND THE THREE NORMAL RETRACT/EXTENSIONS COMPLETED SINCE THE INITIAL ENCOUNTER.

DEPARTING KAUS, AS THEY WERE CLIMBING, THE CREW NOTIFIED ATI MAINTENANCE THAT THE AUTO PILOT PITCH FUNCTION WOULD NOT ENGAGE WHEN AUTO PILOT WAS ON. AFTER REVIEWING THEIR CHECKLIST AND RESETTING AP CBS, SYSTEM STILL NOT ENGAGING, THEY DECIDED TO RETURN TO KAUS. BURNING THE REQUIRED FUEL OFF TO AVOID AN OVERWEIGHT LANDING, THE AIRCRAFT WAS SAFELY LANDED BACK AT KAUS. TROUBLE SHOOTING ON THE GROUND WAS NOT HELPFUL, THE AIRCRAFT WAS FLOWN TO KELP AT LOWER ALTITUDE FOR REPAIRS - NO FIX FOR ISSUES ENCOUNTERED YET.

ON 12/15/2024, N317MP, CYO317, DEPARTED KSNA REPOSITIONING TO KELP AND APPROXIMATELY ONE HOUR INTO THE FLIGHT, THE RH SIDE OF THE INSTRUMENT PANEL STARTED TO GO OUT AND COME BACK. THIS HAPPENED A COUPLE TIMES THEN STAYED OUT. THE CREW DECIDED TO MAKE AN UNSCHEDULED LANDING INTO KPHX. THEY DID DECLARE AN EMERGENCY BUT LANDED SAFELY WITH NO OTHER ISSUES. ATI MAINTENANCE ARRIVED AT THE AIRCRAFT AND FIRST NOTICED THE OUTSIDE OF THE RH ENGINE COWLING HAD BLACK STREAKS USUALLY INDICATING A GENERATOR ISSUE/FAILURE. THE GENERATOR WAS REMOVED AND FOUND TO BE SEIZED WITH THE SHAFT SHEERED OFF. THE GEARBOX/ENGINE WAS INSPECTED WITH NO DISCREPANCIES NOTED. A FRESH OVERHAULED GENERATOR WAS INSTALLED, RH MAIN POWER CURRENT LIMITER WAS FOUND BLOWN AND WAS REPLACED. THE ENGINES WERE RUN INDIVIDUALLY AND THEN TOGETHER WITH MULTIPLE TESTS OF THE GENERATOR COMPLETED WITH LOADS APPLIED. ALL TESTS COMPLETED SATISFACTORILY. THE AIRCRAFT WAS FLOWN TO KELP WITH NO ISSUES.

ON THE MORNING OF 9/21/2024, N824MG WAS DEPARTING EMPTY FROM KLBB HEADING BACK TO KELP WHEN THE CAPTAIN NOTICED THE HYDRAULIC PRESSURE INDICATOR FLUCTUATING. NO OTHER ISSUE OR DISCREPANCY NOTICED. THE CAPTAIN ELECTED TO RETURN TO KLBB FOR PRECAUTIONARY PURPOSES. THE PRESSURE STARTED TO DROP, STILL FLUCTUATING AS THEY TURNED AROUND. THE PRESSURE WAS SLIGHTLY ABOVE ZERO AS THE WERE LINING UP FOR LANDING. THE CAPTAIN DECIDED TO DECLARE AN EMERGENCY. THE AIRCRAFT WAS LANDED SAFELY AND TAXIED BACK TO THE FBO. ALL FUNCTIONS REQUIRING HYDRAULIC PRESSURE WERE COMPLETED BY RESIDUAL PRESSURE FROM ENGINES AND THE STAND BY HYDRAULIC PUMP. NO EMERGENCY AIR WAS NEEDED FOR GEAR EXTENSION OR AIRCRAFT BRAKING. THE CAPTAIN INVESTIGATED THE AREA OF THE AIRCRAFT WHERE HYDRAULIC FLUID WAS FOUND DRIPPING. THE FLUID WAS COMING FROM THE RH INBOARD MAIN GEAR DOOR ACTUATOR RETRACT HYDRAULIC HOSE. ATI JET MAINTENANCE WAS DISPATCHED TO KLBB WITH PARTS AND SUPPLIES. THE DEFECTIVE HOSE WAS REPLACED, THE HYDRAULIC FILTERS WERE REMOVED, FLUSHED AND INSPECTED FOR CONTAMINATION. NO CONTAMINATION FOUND IN THE PRESSURE OR RETURN FILTERS. NEW FILTERS WERE INSTALLED AND THE HYDRAULIC RESERVOIR WAS SERVICED. THE STANDBY HYDRAULIC PUMP WAS RUN AND REQUIRED BLEEDING, A SMALL AMOUNT OF AIR WAS RELEASED DURING THE PROCESS. THE ENGINES WERE RUN INDIVIDUALLY AND PRESSURE INDICATION WAS NORMAL ON BOTH. AFTER TOPPING OFF THE RESERVOIR, THE CREW DECIDED IT WAS SAFE TO ATTEMPT THE RETURN FLIGHT TO KELP. THE FLIGHT WAS COMPLETED WITH NOT ISSUES/DISCREPANCIES REPORTED.

ON SUNDAY, 8/25/2024 N317MP WAS DEPARTING KEGE. ON THE TAKEOFF ROLL, THE CREW REPORTED THE TAKEOFF CONFIGURATION WARNING HORN SOUNDED. THE CAPTAIN ABORTED THE TAKEOFF AND TAXIED OFF THE RUNWAY, THE AIRCRAFT WAS STOPPED AND THE CREW WENT THROUGH THE TAKEOFF CHECKLIST AGAIN. THE CAPTAIN REPORTED THE PARKING BRAKE LEVER DID NOT FULLY SLIDE TO THE "RELEASED" POSITION. BEFORE SETTING IT, HE PUSHED ON THE HANDLE AND IT MOVED 1/4 INCH. THE CAPTAIN STATED THAT HE MIGHT NOT HAVE PUSHED HARD ENOUGH TO FULLY SEAT THE HANDLE AGAINST THE "STOP" WHEN THEY FIRST TAXIED FROM THE FBO. THE CREW COMPLETED THE PRE TAKEOFF CHECKLIST AGAIN, DEPARTED KEGE AND SAFELY AT INTENDED AIRPORT, KIAD. THE AIRCRAFT HAS COMPLETED 5 LANDING SINCE WITH NO ISSUES REPORTED.

DEPARTING KSDL. THE CREW NOTICED A SMOKE/OIL SMELL, WARMER THAN USUAL AIRFLOW WITH SLIGHT VISUAL APPEARANCE OF SMOKE IN THE COCKPIT. THE TAKEOFF WAS ABORTED AND THE AIRCRAFT WAS RETURNED TO THE FBO. AFTER HANDLING THE PASSENGERS, THE CAPTAIN CALLED ATI MAINTENANCE TO DISCUSS THE ISSUE. THE CAPTAIN MENTIONED THAT AS THEY DECIDED TO ABORT, THE SMELL/SMOKE AND WARM AIR FLOW THEY HAD EXPERIENCED HAD ALMOST STOPPED. AFTER DISCUSSING THE ISSUE WITH OPERATIONS, THE DECISION WAS MADE TO RUN THE ENGINES TO DIAGNOSE THE ISSUE AND IF ALL WAS CLEAR, REPOSITION THE AIRCRAFT TO KELP FOR MAINTENANCE. THE ENGINE RUNS WERE COMPLETED WITH VERY MINOR REMNANTS OF THE SMELL. THE CREW DECIDED TO CONTINUE WITH THE REPOSITION TO KELP. THE AIRCRAFT LANDED SAFELY IN ELP A WITH SLIGHT SMOKY SMELL WAS NOTICED DURING THE FLIGHT WHICH WAS MOST LIKELY RESIDUAL FROM THE INITIAL TAKEOFF. THE AIRCRAFT WAS THEN RUN UP BY ATI MAINTENANCE FOR TROUBLESHOOTING PURPOSES, NO OIL/SMOKE SMELL OR EXCESSIVE HEAT WAS NOTICED. A TEST FLIGHT WAS ALSO COMPLETED WITH NO NOTICE OF THE REPORTED ISSUES. NO EXACT CAUSE COULD BE DETERMINED AT THIS TIME. PRIOR TOP TAKE OFF, CREWS COMPLETE PRE TAXI CHECKLISTS, WHERE THE EMERGENCY PRESSURIZATION VALVES ARE TESTED ON THIS CHECKLIST. ONE OF THE EMERGENCY VALVES POSSIBLY DID NOT RESET COMPLETELY WHICH WILL LET WARMER THAN NORMAL AIR INTO THE AIRCRAFT AND WITH THE AIR BEING HOTTER, MAY INTRODUCE ABNORMAL SMELLS. THE AIRCRAFT HAS BEEN RETURNED TO SERVICE DUE TO THE RUNS/TEST FLIGHT NOT PRODUCING ANY OBVIOUS DEFECTS.

ON 5/9/2024 N276BG, CYO276, DEPARTED KELP HEADING TO KSGU, APPROXIMATELY 15 MINUTES INTO THE FLIGHT, THE CAPTAIN NOTICED THE OXYGEN PRESSURE INDICATOR WAS READING ZERO/EMPTY. THE CAPTAIN DECIDED TO RETURN TO KELP. ATI MAINTENANCE MET THE AIRCRAFT AND HOOKED UP THE OXYGEN SERVICE CART TO REPLENISH THE SYSTEM AND THE CART INDICATED THE AIRCRAFTS BOTTLE WAS FULL. MAINTENANCE THEN DISCONNECTED AND RECONNECTED THE PRESSURE TRANSDUCER, PRESSURE INDICATED NORMALLY IN THE COCKPIT. THE OXYGEN SYSTEM CABIN AND COCKPIT WAS TESTED IN AUTO, MASKS WORKED NORMALLY. THE PASSENGER MASKS WERE TESTED MANUALLY, ALL MASKS DROPPED AS THEY SHOULD AND FUNCTIONED NORMALLY. CREW MASKS ALSO FUNCTIONED NORMALLY. ALL MASKS WERE STOWED AND THE SYSTEM RETURNED TO NORMAL. SUSPECTED THE CONNECTOR ON THE PRESSURE TRANSMITTER WAS NOT COMPLETELY SECURE AND CHECKED, IT COUPLED CORRECTLY AND SYSTEM INDICATED FULL. AIRCRAFT WAS RETURNED TO SERVICE.

ON 3/30/2024, DEPARTED KMBS WITH PASSENGERS HEADING TO KSAT. ABOUT 20 MINS INTO FLT, CREW NOTICED A FUEL IMBALANCE IN WINGS. ON CHECKING FUEL CONTROL SWITCH PANEL, NOTICED RT STANDBY PUMP ILLUMINATED & RT JET PUMP WAS TURNED OFF. CAPTAIN CALLED MAINT WHEN ISSUE FIRST NOTICED. DETERMINED TO LAND. CREW LANDED IN KSBN. TAXIED TO PARKING, CAPTAIN VERIFIED LIGHTS WERE ON. SHUT ACFT DOWN. CREW WENT BACK TO ACFT TO TROUBLESHOOT ISSUE. WHEN POWER WAS APPLIED TO ACFT, LIGHTS WERE OUT. POWER CYCLED SEVERAL TIMES TO DUPLICATE ISSUE, DETERMINED LIGHTS HAD COME ON DURING START SEQUENCE WHICH STANDBY PUMP ON & JET PUMP OFF IS NORMAL & CAME BACK ON AT SOME POINT DURING FLT. SEVERAL START ATTEMPTS MADE TO CHECK VALVE SEQUENCING. ALL STARTS NORMAL, ISSUE COULD NOT BE DUPLICATED. OPS & MAINT DECIDED TO HAVE THE CREW FLY TO MAINT HOMEBASE TO LOOK INTO THE ISSUER. SHORT FLIGHTS TO KICT THEN KELP WERE PLANNED. ACFT COMPLETED THE FLIGHTS INTO KELP & LANDED SAFELY WITH NO OTHER ISSUES. START SEQUENCE PROCESS WAS VERIFIED & ISSUE WAS DUPLICATED. SPEED SENSOR CONNECTOR ON RT STARTER WAS FOUND TO BE CAUSING THE ISSUE, START SEQUENCE DID NOT REVERSE/DISENGAGE STANDBY PUMP & JET PUMP AFTER STARTER REACHED A CERTAIN RPM. CONNECTOR FOUND SECURED & SAFETY WIRED BUT THE LOCKING COLLAR WAS WOBBLY & NOT TIGHT. WHILE THE ENGINE WAS RUNNING, MAINTENANCE HAD A HAND ON THE CONNECTOR, AND WHILE MOVING THE CONNECTOR, THE PUMP LIGHTS CAME BACK ON AND WENT OUT WHEN HELD TIGHT. NEW CONNECTOR AND BACK SHELL ORDERED.

ON 2/13/24 LEAR 60-204, N50GJ DEPARTED KRDU WITH PASSENGERS FLYING TO KSTL. APPROXIMATELY ONE HOUR INTO THE FLIGHT, THE CREW NOTICED THE OIL PRESSURE ON THE #2 ENGINE HAD DROPPED 15 PSI. THE CAPTAIN CALLED INTO ATI MAINTENANCE AND NOTIFIED THEM OF THE SITUATION. MAINTENANCE ADVISED THEM TO CONTINUE TO MONITOR THE OIL PRESSURE. THE ROUTE THEY WERE ON WOULD TAKE THEM DIRECTLY OVER NASHVILLE, TN. WHICH THEY WERE 20 MINUTES AWAY FROM. IF THE PRESSURE CONTINUED TO DROP THEY WOULD DIVERT TO KBNA. THE PRESSURE DID DROP AND REQUEST TO DIVERT WAS MADE TO ATC. AS THEY WERE ON FINAL, THE LOW OIL PRESSURE LIGHT ILLUMINATED (COMES ON AT 20 PSI) THE CREW SHUT THE ENGINE DOWN FOR PRECAUTIONARY PURPOSES AND LANDED SAFELY AT KBNA. LOCAL MAINTENANCE DETERMINED THE LEAK CAME FROM THE ACCESSORY DRIVE GEARBOX VENT LINE. PARTS HAVE BEEN ORDERED AND SHIPPED TO THE MAINTENANCE FACILITY WORKING ON THE AIRCRAFT.

ON THE MORNING OF 1/20/24, LEAR 60-087 N601CN, DEPARTED KBFI FLYING TO KEGE. AT CRUISE ALTITUDE, THE #1 ENGINE OIL PRESSURE STARTED TO DROP. THE CAPTAIN CALLED IN TO MAINTENANCE TO INFORM US THE THE SITUATION. THE CREW KEPT FLYING ON THE CHANCE IT WAS AN INDICATION ERROR. THE OIL TEMP WAS THE SAME AS THE #2 ENGINE AND THE LOW OIL PRESSURE LIGHT HAD NOT ILLUMINATED. THE CAPTAIN INFORMED MAINTENANCE THAT IF THE LIGHT CAME ON OR THE PRESSURE CONTINUED TO DROP, THEY WOULD DIVERT INTO KBOI. THE OIL PRESSURE LIGHT TURNS ON AT 20 PSI. THE PRESSURE DID CONTINUE TO DROP AND THE CREW DIVERTED. THEY DECLARED AN EMERGENCY AND LANDED SAFELY AT KBOI. AS THEY WERE ON FINAL, THE LOW PRESSURE LIGHT DID COME ON. THE ENGINE WAS SHUT DOWN SHORTLY AFTER LANDING AND THE AIRCRAFT WAS TAXIED SAFELY TO THE FBO. ATI JET MAINTENANCE WAS SENT TO INVESTIGATE THE ISSUE. AN OIL SEAL ON THE PRIMARY MAGNETIC ALTERNATOR (PMA) WAS WORN AND SLIGHTLY TORN CAUSING THE LEAK. A NEW SEAL WAS INSTALLED AND THE OIL RESERVOIR SERVICED TO FULL. THE ENGINE WAS RUN UP TO FULL POWER, NO LEAKS NOTED. THE AIRCRAFT WAS RETURNED TO SERVICE AND HAS MADE TWO TRIPS WITH NO ISSUES OR LEAKS REPORTED.

ON 10/20/2023, N812RP WAS DEPARTING KSAT WITH PASSENGERS HEADING TO KELP. SHORTLY AFTER TAKEOFF, THE CREW NOTICED THE DUAL BLEED LIGHTS HAD ILLUMINATED. AFTER RUNNING THROUGH THE AIRCRAFT CHECKLIST, THE LIGHTS REMAINED ON AND THE CREW DECIDED TO RETURN TO KSAT. ANOTHER ATI AIRCRAFT WAS DISPATCHED WITH MECHANICS AND TO CONTINUE THE TRIP FOR THE PASSENGERS. ATI MAINTENANCE RAN THE ENGINES AND FOUND A BLOWN SEAL IN THE PNEUMATIC DUCT INTO THE FLOW CONTROL VALVE. AFTER TROUBLE SHOOTING THE PNEUMATIC SYSTEM, IT WAS DETERMINED UNCONTROLLED AIR WAS ENTERING THE PNEUMATIC DUCTS AND OVER PRESSURIZED THE TRANSITION TUBE INTO THE FLOW CONTROL VALVE AND BLEW THE SEAL NEAR THIS VALVE, BLEED AIR BLOWING IN THE AREA OF A HEAT SENSOR LOOP ILLUMINATED THE DUAL BLEED LIGHTS. BY THE PNEUMATIC FLOW SCHEMATIC, THE SOURCE WAS DETERMINED TO BE THE WING ANTI ICE VALVE ON THE RH ENGINE. PARTS WERE SHIPPED AND THE VALVE AND BLOWN SEAL WAS REPLACED. ENGINES AGAIN WERE RAN AND PNEUMATIC/PRESSURIZATION SYSTEM TESTED. NO LEAKS NOTED AND ALL BLEED AIR SHUT OFF/CONTROL VALVES WORKED NORMALLY. THE AIRCRAFT WAS FLOWN TO KELP WITH NO ISSUES REPORTED AND THEN RE INSPECTED. NO DISCREPANCIES/DEFECTS NOTED AT THAT TIME.

ON 6/3/2023, N212JA DEPARTED KELP EMPTY FLYING TO KFST. WHILE PASSING THROUGH 31,000 FT, THE GEAR WARNING/STALL WARNING HORN CAME ON. THE CREW PULLED ASSOCIATED CIRCUIT BREAKERS TO TROUBLE SHOOT & SILENCE THE HORN. KNOWING THE AIRCRAFT WAS NOT IN A STALL AND GEAR, FLAPS AND THROTTLES WERE CORRECT. THE CREW COULD NOT SILENCE THE HORN AND THEY ELECTED TO RETURN TO KELP. ATI MAINTENANCE COMPLETED A STALL WANING FUNCTIONAL TEST ON THE GROUND AND ALL INDICATIONS FOUND TO BE WITHIN LIMITS. THE AIRCRAFT WAS PLACED ON JACKS WITH THE GEAR RETRACTED AND THE AIRCRAFT RUN UP TO 31,000 WITH THE PITOT STATIC TEST SET, TRYING TO DUPLICATE THE SAME SCENARIO. THE WARNING HORNS DID NOT SOUND OFF. ALTITUDES, SPEEDS AND GEAR EXTENDED/RETRACTED WITH NO AURAL WARNINGS. A TEST FLIGHT WAS COMPLETED UP TO 350 ON 6/6/2023 WITH NO ABNORMAL INDICATIONS. THE AIRCRAFT WAS RETURNED TO SERVICE.

ON 4/15/23, N662AR FLEW FROM KVNY TO KLAS. AS THE CREW COMPLETED A NORMAL LANDING OF THE AIRCRAFT IN LAS, THEY WERE INSTRUCTED TO TURN OFF ON A HIGH SPEED TAXI WAY AND PROCEED TO PARKING. THE TRS WERE DEPLOYED AND WORKING NORMALLY. AS THE TURN WAS INITIATED AND TRS STOWED THE CREW REPORTED THE STEERING DID NOT RESPOND AND THE BRAKES HAD LITTLE TO NO PEDAL FEEL WHEN PRESSED. THEY WERE COMING UP ON ANOTHER AIRCRAFT THAT WAS AHEAD OF THEM AND ELECTED TO USE THE EMERGENCY BRAKING (EMER AIR) WHICH SLOWED THE AIRCRAFT WHILE THE AIRCRAFT IN FRONT WAS ABLE TO MOVE ON AND WAS CLEAR. WITH ENOUGH RAMP SPACE AND NO OTHER AIRCRAFT NEARBY, THE AIRCRAFT WAS SLOWING ON ITS OWN INTO A LH TURN, THE CAPTAIN LET IT CONTINUE ON THE TURN WHICH SLOWED THE AIRCRAFT ALMOST TO A STOP. HE THEN CAME TO A COMPLETE STOP WITH A SMALL INPUT OF EMER AIR. HE THEN FELT SOLID BRAKE PRESSURE RESISTANCE ON THE BRAKE PEDALS AND THE STEERING STARTED WORKING AGAIN. THE AIRCRAFT WAS PARKED AT THE FBO WITH STEERING AND BRAKING ACTION WORKING NORMALLY. ON 4/17 ATI JET MAINTENANCE WAS DISPATCHED TO LAS TO INSPECT THE AIRCRAFT. NO DISCREPANCIES WERE FOUND. BRAKING WAS NORMAL, STEERING SYSTEM ALSO FOUND TO BE WORKING NORMALLY. A FERRY PERMIT WAS GRANTED AND A NORMAL TAXI/TAKEOFF DEPARTING LAS WITH THE SAME IN ELP. NO DETERMINATION HAS BEEN MADE AS TO WHAT CAUSED THE ISSUES IN LAS. ALL ANTI SKID COMPONENTS WILL BE TESTED/INSPECTED AS WELL AS THE STEERING SYSTEM COMPUTER, SERVO AND OTHER RELATED ITEMS.

DEPARTING MMUN, AND ON CLIMB, PRESSURIZATION FAULT LIGHT CAME ON & EMERGENCY PRESSURIZATION SYS ACTIVATED. CREW ATTEMPTED TO RESET PRESSURIZATION SYS & IT WOULD NOT. ELECTED TO RETURN TO MMUN. DURING LANDING CHECKLIST, CAPTAIN NOTICED CABIN AIR SWITCH WAS OFF BUT STILL ELECTED TO LAND. LANDED SAFELY. ARRIVED BACK AT THE FBO, THE FAULT LIGHT HAD EXTINGUISHED & EMERGENCY PRESSURIZATION SYS RESET. AT FBO, CREW PERFORMED A FUNCTIONAL CHECK OF PRESSURIZATION SYS. INDICATIONS NORMAL, PRESSURIZATION SYS FUNCTIONED PROPERLY. NEITHER CREW MEMBER KNEW HOW CABIN PRESSURE SWITCH WAS MISSED ON PRE DEPARTURE CHECKLIST. ELECTED TO TAKE OFF AGAIN TO COMPLETE INTENDED FLIGHT. FLIGHT ARRIVED SAFELY INTO KOPF WITH NO ISSUES.

ON SATURDAY 6-25-22, LEAR 60-284, N461MC WAS DEPARTING KAUS HEADING TO KELP, SHORTLY AFTER TAKEOFF THE CREW NOTICED DUAL BLEED AIR LIGHTS ILLUMINATED INDICATING HIGH TEMPERATURE IN THE TAIL SECTION, THE CAPTAIN REDUCED POWER, THE CREW THEN THOUGHT THEY NOTICED A LIGHT SMOKE SMELL. THEY THEN CONTACTED ATC TO RETURN TO KAUS. THE AIRCRAFT WAS LANDED SAFELY BACK AT KAUS. ATI JET MAINTENANCE WAS DISPATCHED TO AUS TO INSPECT THE AIRCRAFT. THE TAIL SECTION WAS ACCESSED TO CHECK FOR ANY BLEED AIR LEAKS WHICH WOULD TURN THE DUAL BLEED LIGHTS ON. THE ENGINES WERE RUN UP TO FULL POWER SEVERAL TIMES - NO LEAKS WERE NOTED AND THE BLEED AIR LIGHTS DID NOT ILLUMINATE. THE AIRCRAFT WAS THEN FLOWN TO ELP WITH NO ISSUES. THE COWLINGS WERE LOWERED TO CHECK TO BLEED AIR MIXING VALVE FUNCTIONS. THE ENGINES WERE RUN UP TO FULL POWER AGAIN THE RH MIXING VALVE DID NOT TRANSITION AT THE RIGHT TIME 1 OUT OF THE THREE FULL POWER RUNS. THE VALVE STAYED IN HIGH PRESSURE LONGER THAN IT SHOULD HAVE. THE BLEED LIGHTS STILL DID NOT ILLUMINATE. THE MIXING VALVE WAS REPLACED AND ENGINE RUNS COMPLETED - ALL INDICATIONS WERE NORMAL. A TEST FLIGHT WAS ALSO COMPLETED WITH NO ISSUES/DISCREPANCIES.

ON 5/27/2022, CYO601 (N601CN) DEPARTED KUES GOING TO KLAS. IN CRUISE FLIGHT THE CREW NOTIFIED ATI MAINTENANCE THAT THE RH HYDRAULIC PRESSURE LIGHT HAD COME ON, HYDRAULIC PRESSURE WAS STEADY. APPROXIMATELY 5 MINUTES LATER, THE CREW NOTIFIED ATI MAINTENANCE THAT THEY HAD LOST 150 PSI OF HYDRAULIC PRESSURE. AFTER NOTIFYING ATIS DIRECTOR OF OPERATIONS, WE INSTRUCTED THE CREW TO LAND AS SOON AS POSSIBLE. THEY ELECTED TO LAND AT KMTJ. THE CREW LANDED THE AIRCRAFT SAFELY WITH NO FURTHER LOSS OF HYDRAULIC PRESSURE. ATI MAINTENANCE WAS SENT TO MTJ, THE RH ENGINE DRIVEN HYDRAULIC PUMP DRIVE SHAFT HAD SHEARED. THE PUMP WAS CHANGED AND THE HYDRAULIC PRESSURE AND RETURN FILTERS WERE PULLED FOR INSPECTION - MINOR CONTAMINATION WAS FOUND IN THE PRESSURE RETURN FILTER. THE FILTER WAS CLEANED AND REINSTALLED. THE HYDRAULIC SYSTEM WAS CYCLED AND FILTERS PULLED AND CLEANED - REPEATED 2 MORE TIMES. NO CONTAMINATION FOUND ON THE LAST REMOVAL. THE AIRCRAFT WAS FLOWN TO KELP AND ATI JET MAINTENANCE REMOVED THE FILTERS AGAIN TO INSPECT FOR CONTAMINATION. A VERY SMALL AMOUNT HAD COLLECTED IN THE RETURN FILTER AND NONE IN THE PRESSURE SIDE. NEW FILTERS WERE INSTALLED AND THE THE AIRCRAFT WAS RETURNED TO SERVICE.

ON THE MORNING OF MARCH 9TH 2022, LEAR 55 N277AL DEPARTED KMAF. ON CLIMB APPROACHING 10,000 FT, THE LH ENGINE FIRE LIGHT FLASHED. THE CAPTAIN SCANNED THE ALL OF THE ENGINE INSTRUMENTS AND NOTICED THE LH ENGINE EGT WAS APPROACHING 930 DEGREES. THE CAPTAIN REDUCED POWER AND CONTACTED ATC TO REQUEST A RETURN TO MAF. AFTER ANOTHER SCAN OF ENGINE INSTRUMENTS, THE EGT HAD DROPPED BUT THEN THE FIRE LIGHT FLASHED AGAIN. HE THEN PULLED THE FUEL SHUT OFF AND SHUT THE LH ENGINE DOWN THEN DECLARED AN EMERGENCY. THE AIRCRAFT LANDED SAFELY AT MAF WITH NO OTHER ISSUES. THE CREW INSPECTED THE LH ENGINE COWLING AND PYLON THERE WAS NO SIGN OF FIRE OR OVER TEMP. THE AIRCRAFT WILL REMAIN AT MAF UNTIL AN ATI MAINTENANCE CREW CAN BE DISPATCHED FOR THE R&R OF THE LH ENGINE.

ON THE MORNING OF APRIL 4, 2022, N812RP DEPARTED KOPF WITH PASSENGERS HEADING TO KELP. AFTER TAKEOFF THE CREW NOTIFIED ATI MAINTENANCE THROUGH AIRTEXT THAT THE AIRCRAFT DID NOT PRESSURIZE. THE CREW HAD ALREADY WENT THROUGH THE RESET PROCEDURES AND REPORTED THAT IT STILL WOULD NOT PRESSURIZE, THE EMERGENCY PRESSURIZATION SYSTEM THEN ACTIVATED, THE CABIN/COCKPIT WAS GETTING VERY WARM AND THE EMERGENCY VALVES WOULD NOT RESET EITHER. ATI MAINTENANCE SUGGESTED A RETURN TO OPF WHICH THE CREW HAD ALREADY REQUESTED. THE AIRCRAFT LANDED SAFELY BACK IN OPF. AN ATI JET MAINTENANCE CREW ARRIVED IN OPF AND COMPLETED A FULL FUNCTIONAL CHECK OF THE PRESSURIZATION SYSTEM INCLUDING THE EMERGENCY PRESSURIZATION SYSTEM. NO FAULTS WERE RECORDED ON THE PRESSURIZATION COMPUTER AND THE AIRCRAFT PRESSURIZATION SYSTEM ACTIVATED NORMALLY ACCORDING TO THE PROCEDURES IN THE LEAR 60 MM. THE EMERGENCY PRESSURIZATION SYSTEM ALSO FUNCTIONED AND RESET NORMALLY. ANOTHER CREW FLEW THE AIRCRAFT FOR TESTING PURPOSES, ALL PRESSURIZATION SYSTEM FUNCTIONS WERE NORMAL. AUTOMATIC MODE AND MANUAL MODE WERE TESTED. WITH ALL FUNCTIONS NORMAL, THE AIRCRAFT WAS RELOCATED TO KDAL WITH NO ISSUES. IT IS SUSPECTED THAT THE CREW DID NOT HAVE THE CABIN AIR SWITCH ON AT TAKEOFF AND WHEN THE SYSTEM RESET WAS INITIATED, THE COMPUTER/BLEED VALVES WEREN'T GIVEN ENOUGH TIME TO "RESET" SO THE SYSTEM DID NOT FUNCTION NORMALLY AND WOULD NOT PRESSURIZE.

ON 4/2/22, N317MP WAS DEPARTING KGLS HEADING TO KCHS. AFTER TAKEOFF CLIMBING THROUGH 9000FT, THE LH ENGINE FIRE LIGHT ILLUMINATED. THE CREW SCANNED ALL INSTRUMENTS AND NO ABNORMAL INDICATIONS WERE NOTICED. AFTER REVIEWING AND COMPLETING THEIR CHECKLIST THEY DETERMINED IT WAS A FALSE INDICATION BUT DECIDED TO DIVERT INTO KHOU FOR PRECAUTIONARY PURPOSES. ATI JET MAINTENANCE PERSONNEL WERE NOTIFIED AND FLEW TO KHOU ON THE RECOVERY AIRCRAFT. MAINTENANCE PERSONNEL INSPECTED THE AIRCRAFT - THERE WAS NO SIGN OF FIRE. MAINTENANCE THEN TESTED THE FIRE DETECTION SYSTEM FOR THE LH ENGINE. THE SYSTEM TESTED NORMAL ON THE GROUND. THE LH ENGINE WAS RUN UP TO FULL POWER AND VARIOUS POWER SETTINGS TO TRY TO DUPLICATE THE FIRE INDICATION. NO BLEED AIR LEAKS NOTICED. COULD NOT BE DUPLICATED. ONE SMALL SECTION OF THE PYLON FIRE SENSOR LOOP WAS FOUND TO BE RESTING ON A BLEED AIR LINE THAT WAS WRAPPED IN FIRE SLEEVE. THIS SECTION WAS REPOSITIONED TO MOVE AWAY FROM BLEED AIR LINE. THE AIRCRAFT WAS FLOWN TO KELP WITH NO OTHER FIRE INDICATIONS. THE AIRCRAFT HAS MADE TWO MORE TRIPS WITH NO INDICATIONS OF FIRE ON THE LH ENGINE.

AFTER DEPARTURE FROM KPBI HEADING TO KMMU WHILE CLIMBING THROUGH 230, THE CREW NOTICED THE LH & RH BLEED LIGHTS ILLUMINATED. AFTER FOLLOWING THE CHECKLIST , THE LIGHTS WENT OUT SO THE CREW ELECTED TO CONTINUE. THEN WHILE CLIMBING THROUGH 310 THE LIGHTS CAME BACK ON, AS THE CREW COMPLETED THE STEPS IN THE CHECKLIST, THE DUCT OVERHEAT LIGHT ILLUMINATED. THE CREW THEN ELECTED TO MAKE AN UNSCHEDULED LANDING INTO KMCO. AN EMERGENCY WAS DECLARED AND THEY DIVERTED. AFTER LANDING SAFELY IN MCO, THE CREW NOTIFIED ATI MAINTENANCE. MAINTENANCE PERSONNEL FROM ATI FLEW TO MCO TO INSPECT N601CN, THE TAIL SECTION WAS OPENED TO ACCESS ALL OF THE BLEED AIR TUBES AND SENSORS. BOTH ENGINES WERE RUN UP TO TAKE OFF POWER FOR SEVERAL MINUTES WHILE MAINTENANCE CHECKED THE TAIL SECTION FOR LEAKS - NO LEAKS WERE FOUND. A FUNCTIONAL CHECK OF THE CREW AND CABIN HEAT SYSTEM WAS COMPLETED AT THE SAME TIME TO DUPLICATE THE DUCT OVERHEAT LIGHT/MALFUNCTION. THE DUCT OVERHEAT LIGHT NEVER CAME ON - COULD NOT DUPLICATE EITHER MALFUNCTION ON THE GROUND. THE AIRCRAFT WAS FLOWN TO KELP (STOPPING IN KHOU FOR FUEL) FOR FURTHER INVESTIGATION AND INSPECTION OF THE BLEED AIR/TEMPERATURE CONTROL SYSTEM.

ON SEPTEMBER 20, 2021 N924PS DEPARTED EMPTY FROM KDAL HEADING TO KMAF. THE CAPTAIN NOTICED THE LH ENGINE OIL PRESSURE INDICATOR SHOWED ZERO PSI AND THE LOW OIL PRESSURE LIGHT ON THE ANNUNCIATOR PANEL WAS ON. HE MOVED THE THROTTLE LEVER TO IDLE THEN TO CUTOFF AND REQUESTED A RETURN TO KDAL. AFTER LANDING SAFELY AT DAL, MAINTENANCE WAS CALLED TO INVESTIGATE THE LOSS OF OIL PRESSURE. DALLAS AIRMOTIVE INFORMED ATI MAINTENANCE THAT THE ENGINE AND COWLING WERE OIL SOAKED. NO DEFINITIVE CAUSE OF LOSS OF OIL AND OIL PRESSURE COULD BEEN DETERMINED. OIL WAS ADDED AND ENGINE WAS MOTORED - SLIGHT OIL PRESSURE WAS INDICATED. AN ENGINE START WAS ATTEMPTED AND MAINTENANCE THOUGHT A "HUNG" START RESULTED. WITH FURTHER INVESTIGATION, MAINTENANCE FOUND THAT THE N1 STAGE HAD SEIZED. THE ENGINE WILL BE REMOVED FROM THE AIRCRAFT AND DISASSEMBLED TO TRY TO DETERMINE THE CAUSE.

ON THE AFTERNOON OF 6-4-2021, DEPARTING OUT OF KMDQ AND HEADING TO KBJC, THE CREW FELT A SLIGHT VIBRATION THROUGHOUT THE AIRPLANE PROGRESSIVELY GETTING WORSE. NO ABNORMAL INDICATIONS WITH ANY OF THE AIRCRAFT SYSTEMS WAS NOTED. THEY DECIDED TO DIVERT INTO KMEM WHERE THEY LANDED SAFELY. THE VIBRATION WAS STILL PRESENT ON THE GROUND WITH ENGINES RUNNING. ON THE GROUND THE CREW COMPLETED THEIR "WALKAROUND" AND NOTICED THE RH ENGINE COWLING HAD BLACK SOOT EXITING FROM THE STARTER/GENERATOR COOLING DUCT EXIT. MAINTENANCE WAS DISPATCHED FROM EL PASO WITH A NEW STARTER/GENERATOR AND INSTALLED IT ONTO THE AIRCRAFT. ENGINE RUNS COMPLETED, NO VIBRATIONS NOTED. THE CREW CONTINUE THEIR FLIGHT INTO KBJC WITH NO OTHER ISSUES/VIBRATIONS NOTED.

DEPARTING FROM MMUM, THE CREW NOTICED A FAULT LIGHT ON THE PRESSURIZATION CONTROL PANEL ILLUMINATED AND THE AIRCRAFT WOULD NOT PRESSURIZE. THEY COMPLETED THEIR CHECKLIST FOR PRESSURIZATION FAULTS, FAULT LIGHT REMAINED ON. AFTER BURNING ENOUGH FUEL TO MEET LANDING REQUIREMENTS, THEY LANDED SAFELY BACK AT MMUM. ANOTHER ATI JET AIRCRAFT WAS DISPATCHED TO COMPLETE THE INTENDED TRIP. THE CREW SWAPPED TO EXPEDITE THE PASSENGERS DEPARTURE. THE SECOND CREW PERFORMED A PRESSURIZATION CHECK ACCORDING TO THE LEARJET M.M. ALL INDICATIONS WERE NORMAL AT THAT TIME. THE CREW DECIDED TO REFUEL AND ATTEMPT THE FLIGHT TO KELP, AFTER REFUELING, JUST BEFORE TAKE OFF, ANOTHER PRESSURIZATION CHECK WAS PERFORMED WITH NO DISCREPANCIES NOTED. THE AIRCRAFT COMPLETED THE INTENDED FLIGHT BACK TO KELP WITH NO ISSUES. ATI MAINTENANCE COMPLETED A DETAILED INSPECTION OF THE PRESSURIZATION SYSTEM WITH NO PROBABLE CAUSES DISCOVERED.

ON 11-29-2020 N924PS DEPARTED KLAS FLYING TO KELP, ON CLIMB OUT OF LAS, THE CREW NOTICED THE LT & RT BLEED LIGHTS ON INDICATING AN OVERHEAT CONDITION IN THE TAIL/BAGGAGE COMPARTMENT. AFTER COMPLETING THEIR CHECKLIST, THE CAPTAIN DECIDED TO DIVERT INTO KPRC. AFTER DECLARING AN EMERGENCY AND STARTING THE DESCENT, THE BLEED LIGHTS WENT OUT AND DID NOT COME BACK ON. THE AIRCRAFT WAS LANDED SAFELY IN PRC, THE AFT BAGGAGE AND TAIL CONE AREAS WERE INSPECTED AND FOUND TO BE COLD COMPARED TO HOT CONDITIONS WHEN BLEED AIR LEAKS ARE FOUND. THE CAPTAIN AND ATI OPERATIONS DETERMINED IT WAS A FALSE INDICATION AND THE AIRCRAFT CONTINUED ON ORIGINAL COURSE TO KELP. ALL INDICATIONS WERE NORMAL ON THE FLIGHT FROM PRC TO ELP AND LANDED SAFELY IN ELP.

ON 10/8/2020, N824MG DEPARTED KLNK WITH PASSENGERS FLYING TO KELP. AFTER TAKEOFF THE CREW ATTEMPTED TO START THE FUEL TRANSFER AND NOTICED THE TRANSFER/CROSS FLOW VALVES TRANSITION LIGHTS WERE NOT ILLUMINATING WITH ANY OF THE TRANSFER OPTIONS. THE CAPTAIN NOTICED THE CROSS FLOW VALVE CIRCUIT BREAKER WAS POPPED. THE CAPTAIN RESET THE CB ONCE, IT IMMEDIATELY POPPED. THE CAPTAIN THEN DECIDED TO DIVERT INTO KSLN. HE LANDED THE AIR CRAFT SAFELY IN KSLN. ANOTHER ATI JET AIRCRAFT WAS DISPATCHED WITH MAINTENANCE PERSONNEL AND TO PICK UP PASSENGERS. ATI MAINTENANCE DETERMINED THE FUEL TRANSFER RELAY BOX WAS THE CAUSE OF THE CROSS FLOW VALVE CB POPPING. A SERVICEABLE BOX WAS INSTALLED AND A FUEL SYSTEM TRANSFER FUNCTIONAL CHECK WAS COMPLETED. ALL VALVES AND TRANSITION LIGHTS WERE WORKING NORMALLY. THE CROSS FLOW CB DID NOT POP. N824MG WAS FLOWN TO KELP WITH NO FURTHER ISSUES.

DEPARTED KFCM, REFUELED AT KLNK. DURING FLIGHT, PILOTS BANKED HARD LEFT, EMERGENCY DESCENT TO LAND IN SALINA, KS. CHIEF PILOT STATED "FUEL CONTROL VALVE FAILED AND WERE 'DANGEROUSLY LOW ON FUEL'". HE FURTHER STATED, "OUR 55'S ARE OLD AND SOMETHING'S ALWAYS BREAKING IN THEM." SUGGESTS TO ME THAT MAINTENANCE AND SAFETY IS AN ISSUE FOR ATI JET AND SHOULD BE INVESTIGATED.

CLIMBING THROUGH 18,000 FT. THE LT & RT BLEED LIGHTS CAME ON WHICH INDICATE AN OVERHEAT IN THE TAIL CONE. THE CREW WENT THROUGH THEIR CHECKLIST AND LIGHTS WERE STILL ON. THEY RETURNED TO DEPARTURE. MAINTENANCE INSPECTED THE BLEED AIR SYSTEM AND PERFORMED ENGINE RUNS WITH THE PRESSURIZATION SYSTEM ON. A SMALL BLEED AIR LEAK WAS FOUND AT THE SPLIT OF THE V BAND CLAMP THAT SECURES THE FLOW CONTROL VALVE TO THE BLEED AIR TUBES BLOWING DIRECTLY ON THE FIRE LOOP SENSOR ELEMENT. THEIR IS NO GASKET IN THIS CLAMP, THE "V BAND WAS LOOSENED AND RE POSITIONED , RE ALIGNING THE FLOW CONTROL VALVE AND BLEED TUBE. RE TORQUED THE "V BAND" CLAMP AND COMPLETED ENGINE RUNS AND FUNCTIONAL CHECK OF THE PRESSURIZATION SYSTEM. ALL FUNCTIONS WERE NORMAL WITH NO LEAKS NOTED. THE AIRCRAFT CONTINUED ON THE SCHEDULED FLIGHT WITH NO BLEED LIGHTS ILLUMINATING.

SCHEDULED TRIP FROM ELP TO TUS PICKING UP PASSENGERS AND CONTINUING ON TO FCM. THE FLIGHT WAS NORMAL FROM ELP TO TUS. AFTER DEPARTING TUS, DURING CLIMB TO CRUISE ALTITUDE, THE LT AND RT BLEED LIGHTS CAME ON INDICATING AN OVER TEMP IN THE TAIL SECTION. THE CAPTAIN REDUCED POWER TO SEE IF THE LIGHTS WOULD GO OUT. LIGHTS REMAINED ON, THE CREW THEN COMPLETED THE CHECKLIST REQUIREMENTS AND THROUGH AIR TEXT NOTIFIED ATI MAINTENANCE AND DISPATCH THAT THEY WERE DIVERTING TO AMA. LANDED SAFELY AT AMA. ANOTHER COMPANY PLANE WAS DISPATCHED TO COVER THE REMAINING PORTION OF THE TRIP. MAINTENANCE PERSONNEL COMPLETED AND INSPECTION OF THE TAIL SECTION BLEED AIR LINES AND FIRE DETECTION COMPONENTS. NO LEAKS WERE NOTICED. TWO SECTIONS OF THE TEMPERATURE SENSOR (FIRE LOOP) WERE FOUND TO BE VERY CLOSE TO BLEED AIR LINES AND FLOW CONTROL VALVE. THE FIRE LOOP WAS RE-POSITIONED AND SECURED PROPERLY. A FUNCTIONAL TEST OF THE FIRE WARNING SYSTEM WAS COMPLETED, SYSTEM TESTED NORMAL. HIGH POWER ENGINE RUNS WERE COMPLETED WITH NO TEMPERATURE WARNING INDICATIONS. THE AIRCRAFT WAS FLOWN TO MAIN OFFICE (ELP) WITH NO WARNING LIGHTS ILLUMINATING.

CLIMBING THROUGH 23,000 FEET LEFT ENGINE SHUT DOWN AND FUEL COMPUTER LIGHTS CAME ON. ENGINE RESTART ATTEMPTED BUT WOULD NOT RESTART. AIRCRAFT MADE UNSCHEDULED LANDING SAFELY. MAINTENANCE EVALUATION REPORTED ELECTRONIC ENGINE CONTROL HAD FAILED. CONFIRMATION IN PROCESS.

ON 5-8-2019, DEPART BHM TO MAF. AT APPROXIMATELY 120 KNOTS ABOUT TO TAKE OFF, THE NR 1 & 2 MAIN TIRES BLEW OUT AT THE SAME TIME. THE CAPTAIN STOPPED THE AIRCRAFT SAFELY ON A TAXI WAY. THE CREW COULD NOT DETERMINE IF THEY HAD RUN OVER DEBRIS OR NOT, THE CREW STATED THE TIRES HAD BEEN INSPECTED ON THE PRE FLIGHT AND WERE IN GOOD CONDITION. MAINTENANCE FROM THE AIRCRAFTS HOME BASE ARRIVED IN BHM LATER THAT DAY. THE NR 1 & 2 WHEELS AND BRAKES WERE DAMAGED BEYOND USE. SERVICEABLE WHEELS AND BRAKES WERE INSTALLED. THERE WAS SMALL DENT IN THE WING LEADING EDGE DIRECTLY IN FRONT OF THE MAIN GEAR AND A SMALL HOLE PUNCHED INTO THE LOWER SKIN OF THE LT FLAP. THERE WAS ALSO FOUR SMALL DENTS IN THE SAME GENERAL AREA OF THE HOLE. LEARJET ENGINEERING WAS NOTIFIED AND SUPPLIED A LETTER OF RECOMMENDATION FOR TEMPORARY REPAIRS TO FERRY THE AIRCRAFT TO ITS HOME BASE. AFTER THE COMPLETION OF THE TEMPORARY REPAIRS, THE AIRCRAFT AND ENGINES WERE INSPECTED FOR ANY OTHER POSSIBLE DAMAGE, NONE NOTED. THE AIRCRAFT BRAKING/ANTI SKID SYSTEM WAS TESTED WITH ALL SYSTEMS FUNCTIONING NORMALLY. A FERRY PERMIT WAS ISSUED AND THE AIRCRAFT ARRIVED SAFELY INTO ELP WITH NO ISSUES.

IN CRUISE FLIGHT IN ROUTE TO KSGR THE CREW ON FLIGHT CYO277 NOTICED THE RT STALL WARNING INDICATOR FLUCTUATING. NO CROSSWINDS NOTICED AT TIME. THE LT INDICATOR WAS STABLE. THE CAPTAIN ELECTED TO RETURN TO ELP. HE TURNED THE RT STALL WARNING OFF FOR THE RETURN. THE AIRCRAFT RETURNED TO ELP WITH NO OTHER ISSUES. A COMPLETE STALL WARNING FUNCTIONAL CHECK WAS COMPLETED IAW THE MM. NO DISCREPANCIES WERE NOTED. THE RT STALL WARNING INDICATOR WAS REPLACED WITH A SERVICEABLE UNIT FOR TROUBLE SHOOTING PURPOSES AND THE FUNCTIONAL TEST WAS COMPLETED AGAIN WITH NO DISCREPANCIES NOTED. THE AIRCRAFT WAS RETURNED TO SERVICE.