PREMIER AIR, INC.

ON MAY 1, 2025, N80PK DEPARTED KBCT IN ROUTE TO KHPN WITH PAX. AT FL410 THE CREW NOTICED THE CABIN RATE BEGINNING TO CLIMB. SHORTLY AFTER, THE CABIN ALT LIGHT ILLUMINATED AND ALL O2 MASKS DEPLOYED. CREW ALERTED ATC OF THE ISSUE. THE CREW COMPLETED EMERGENCY CHECKLIST PROCEDURES AND DESCENDED TO FL150. THEY DIVERTED TO KORF AND LANDED SAFELY. UPON INSPECTION, MAINTENANCE DISCOVERED THAT A FLEXIBLE HOSE DOWNSTREAM OF THE SILENCER-MIXER DUCT ASSEMBLY HAD BECOME DETACHED. THE HOSE WAS RESECURED, AND AN OPERATIONAL CHECK OF THE PRESSURIZATION SYSTEM WAS PERFORMED, AND NO OTHER DEFECTS WERE NOTED AT THIS TIME. LOGBOOK RESEARCH WAS PERFORMED FOR PAST MAINTENANCE COMPLETED ON THAT DUCT WITH NO DISCREPANCIES NOTED

IN CRUISE AT FL 410 IN SMOOTH CLEAR CONDITIONS THE LEFT WINDSCREEN OUTER LAYER OF GLASS STARTED TO DELAMINATE. THE WINDSCREEN WAS OPERATING NORMALLY. THE CREW IMMEDIATELY CHECKED THE CABIN PRESSURE WHICH REMAINED NORMAL WITH A CABIN ALTITUDE OF 8000 FEET AND CABIN PRESSURE OF APPROXIMATELY 8 PSI. THE CREW CONFIRMED THE INSIDE LAYER OF GLASS WAS INTACT. THE CREW HAD A BRIEF DISCUSSION ON THE OPTIONS AND COURSE OF ACTIONS. THEY WERE DUE SOUTH OF KRIC AND MADE A DECISION TO DECENT TO 10,000 FEET AND REDUCE SPEED TO ELIMINATE AS MUCH STRESS AS POSSIBLE ON THE WINDSHIELD. CREW ALERTED ATC OF THE PROBLEM AND ASKED FOR A PRIORITY DECENT. ATC REQUESTED THE NATURE OF THE PROBLEM AND GAVE A PROMPT DESCENT TO 10,000 FEET AND DIRECT TO KRIC. ATC DECLARED THE EMERGENCY. APPROACH WAS FLOWN BY THE COPILOT, AS VISIBILITY WAS VERY LIMITED FROM THE CAPTAIN SIDE. NORMAL CHECKLISTS WERE COMPLETED, PASSENGERS BRIEFED ON THE SITUATION. A NORMAL APPROACH AND LANDING WERE COMPLETED. MX TRAVELED TO KRIC AND REPLACED THE LEFT WINDSHIELD

ON LANDING IN BUF, AFTER GEAR EXTENSION AND FLAPS 45 NOTICED NO GREEN LANDING GEAR LIGHTS. NOSE GEAR PIN WAS OUT INDICATING DOWN AND LOCKED NOSE GEAR. PERFORMED GO AROUND, FOUND GEAR LIGHTS CB POPPED, TRIED TO RESET ONCE, WOULD NOT RESET. CREW FORGOT TO CHECK MLG SECONDARY INDICATIONS, AND THEY ATTEMPTED AUX HYDRAULIC SYSTEM TO LOWER GEAR, RESISTANCE IN HANDLE SHOWED GEAR WAS DOWN AND LOCKED. MADE A NORMAL LANDING. GEAR LIGHTS CB WOULD RESET AFTER SHUTDOWN. AFTER DEBRIEFING WITH THE CREW, ALL SECONDARY GEAR DOWN LOCK INDICATORS WERE OPERATIONAL. MX TROUBLESHOT LANDING GEAR INDICATION SYSTEM. FOUND WIRE HARNESS IN NOSE GEAR TO BE STUCK BETWEEN NOSE GEAR DOOR RELEASE LEVER AND INDICATOR MICROSWITCH, CAUSING IMPROPER SWITCH FUNCTION. REPAIRED AND REPOSITIONED WIRING AND SECURED. OPERATIONAL CHECK GOOD AT THIS TIME.

3/24/24 N560TA DEPARTED KFLL TO KHYA. CRUISING AT FL390 THE CREW HEARD A LOUD WHISTLE COMING FROM THE DOOR SEAL. THE CREW NOTICED THAT THE CABIN ALTITUDE WAS CLIMBING AND ASKED FOR A DESCENT. COMING TO FL240 THE CABIN PRESSURE WOULD NOT STABILIZE AND BEGAN TO CLIMB. THE CREW-INITIATED CABIN DECOMPRESSION CHECKLIST AND ASKED FOR ALT 10,000 FROM ATC WHILE DIVERTING TO KCHS. ONCE AT ALT 10,000 THE CABIN STABILIZED, AND THE CREW DOWNGRADED THE EMERGENCY AND LANDED IN KCHS WITH NO FURTHER ISSUES. MAINTENANCE REPLACED DOOR SEAL WITH NEW AND OPERATIONAL CHECK GOOD AT THIS TIME.

APPROXIMATELY 1 HR INTO FLT AT FL410, AUTOPILOT DISCONNECTED WITHOUT ANY AURAL IND. ATTEMPTED TO RE-ENGAGE AUTOPILOT BUT DID NOT ENGAGE. NO ANNUNCIATED FD MODES & SEVERAL UNSUCCESSFUL ATTEMPTS WERE MADE TO SELECT ROLL & PITCH MODES WITH FD CONTROL PANEL. FD COMMAND BARS ON PILOT’S EADI REMAINED OUT OF VIEW. PILOT’S EHSI SHOWED A RED X ACROSS INSTRUMENT & APPEARED HEADING INFO NOT VALID. PILOT RESUMED MANUAL HAND-FLYING ACFT RELYING ON STDBY INST. CO-PILOT’S FD REMAINED IN VIEW BUT HAD NO WAY OF SETTING HEADING USING HEADING BUG, IT WAS NOT OPERABLE VIA REMOTE CONTROLLER. NO VISIBLE HEADING BUG ON PILOT’S PFD OR MFD. NO PRESELECT ALTITUDE VALUE VISIBLE ON PILOT’S PFD OR MFD, ONLY DASHES. PILOT ATTEMPTED TO REVERT TO CO-PILOT’S HEADING SYS, USING HEADING REVERSION BUTTON, NO SUCCESS. MFD DISPLAYED “MENU INOP. DECISION MADE TO DECLARE AN EMERGENCY & DIVERT TO KCLT WHERE VFR WX REPORTED & A VISUAL APPROACH CONDUCTED. A NORMAL LANDING MADE IN KCLT. MX FOUND EFIS CONTL 1 C/B TRIPPED. RESET BREAKER & OPS CHKD A/P & OTHER SYS & COULD NOT DUPLICATE FAILURE. WHEN DESCRIBING THE EVENTS TO MAINTENANCE, ONE OF THE ITEMS THE PILOT MENTIONED WAS AN ISSUE WITH THE PILOTS PUSH TO TALK SWITCH NOT WORKING. AT THE TIME IT WAS BELIEVED TO BE UNRELATED TO THE AVIONICS ISSUE BUT WE DID HAVE MAINTENANCE CHECK IT. THEY COULD NOT DUPLICATE ANY ISSUE WITH IT AND FOUND IT TO OPERATE NORMALLY. THE NEXT DAY WHEN THE CREW WAS PREPARING TO DEPART THEY REPORTED IT WASN’T WORKING AGAIN SO IT WAS DEFERRED PER THE MEL. IT WAS LATER DETERMINED THAT THE REASON THE SWITCH WAS INTERMITTENT WAS BECAUSE IT WAS GETTING PRESSED TOO DEEP INTO THE YOKE SWITCH BUSHING. IF THE SWITCH WAS PRESSED TOO HARD IT WOULD COME INTO CONTACT WITH THE AUTO-PILOT DISCONNECT SWITCH CONTACT IN THE YOKE AND TRIP THE CB.

WHILE CRUISING AT FL370 48 MINUTES INTO A FLIGHT (KSUA-KTTN), THE CREW SENSED A MECHANICAL/BURNING ODOR (POSSIBLY OIL) COMING FROM THE PRESSURIZATION SYSTEM. AIR SUPPLY SOURCES WERE ISOLATED TO IDENTIFY THE ORIGIN OF THE SMELL (LEFT OR RIGHT ENGINE BLEED AIR SUPPLY). TROUBLESHOOTING EFFORTS WERE INCONCLUSIVE, DESTINATION WAS CHANGED TO KSAV. AFTER LANDING MAINTENANCE ACCOMPLISHED ENGINE RUNS WITH CREW WITH NO ABNORMAL SMELLS NOTED WHILE ALTERNATED BLEEDS SOURCES AND ACM ON/OFF. INSPECTED ACM AND DUCTING WITH NO DEFECTS FOUND. INSPECTED AND DRIED WATER SOCK WITH NO DEFECTS FOUND. ACCOMPLISHED IAW CESSNA 550 AMM 21-23-00.

WHILE CLIMBING OUT A HIGH FREQUENCY SOUND OCCURRED AT ABOUT 10,000FT. AT ABOUT 25,000FT A STRONG VIBRATION DEVELOPED AND THE SOUND INTENSIFIED AND CABIN AND COCKPIT BEGAN TO FILL WITH SMOKE. ALL ENGINE INSTRUMENTS LOOKED NORMAL ALTHOUGH CLIMB PERFORMANCE SEEMED SLOW. MADE DESCENT AND WITH POWER AT IDLE SMOKE DECREASED. WHEN WE ADDED POWER FOR THE APPROACH SMOKE REOCCURRED. ON THE GROUND DURING A MAINTENANCE TEST RUN UP THE LEFT ENGINE STALLED SEVERAL TIMES IN QUICK SUCCESSION. IMMEDIATELY REDUCED POWER AND SHUT THE ENGINE DOWN.

AT FL 410 "DOOR SEAL" ANNUNCIATOR ILLUMINATED. SHORTLY AFTER THAT CABIN ALTITUDE STARTED CLIMBING 5000-6000 FT PER MINUTE. PERFORMED EMERGENCY DECENT WITH OXYGEN ON. DECLARED EMERGENCY AND DESCENDED TO 9000 FT. UPON INSPECTION OF ALL ASSOCIATED COMPONENTS THAT MAKE UP THE DOOR SEAL SYSTEM, NO PHYSICAL DAMAGE TO ANY PARTS WERE NOTED. CONNECTED TO SERVICE AIR MAINTENANCE PORT AND PURGED WITH DRY NITROGEN. OBSERVED THE ACTUATION OF THE MAIN DOOR CABIN SEAL WITH NO DEFECTS NOTED. BOTH DOOR ANNUNCIATORS WERE CHECKED FOR PROPER RIGGING. SUSPECT MOISTURE IN THE SERVICE AIRLINE DUE TO MOISTURE THAT WAS INITIALLY FOUND AROUND THE DOOR HINGE UPON OPENING THE DOOR ON GROUND.

NOSE LANDING GEAR WOULD NOT REMAIN UP AND LOCKED. HYDRAULIC SYSTEM WAS CYCLING ON/OFF. FOUND NOSE STRUT EXTENSION GREATER THAN THE MAXIMUM ALLOWABLE WHICH PREVENTED IMPROPER ENGAGEMENT OF THE NOSE GEAR IN THE UPLOCK HOOK. FOUND COLLAR ON THE TOP OF THE NOSE STRUT PISTON LOOSE. AS THIS COLLAR BACKED OFF THE LANDING GEAR STRUT PISTON EXTENDED TOO FAR. RETORQUED NUT AND REASSEMBLED THE NOSE STRUT AND SERVICED. NOSE GEAR STRUT EXTENSION NOW WITHIN LIMITS. FUNCTION CHECK OF LANDING GEAR SYSTEM WAS NORMAL.

DURING PRE-PURCHASE SURVEY, INSPECTED ENGINE OIL FILTER AND FOUND LARGE AMOUNT OF METAL DEBRIS. ENGINE REMOVED FROM SERVICE AND SENT TO OVERHAUL FACILITY FOR REPAIR OR OVERHAUL.

CUSTOMER EXPERIENCES INTERMITTENT PITCH TRIM/AUTOPILOT DISCONNECT ISSUE. CHECKED PITCH TRIM ACTUATOR BY PUSHING UP AND DOWN ON HORIZONTAL STABILIZER L/E. FELT AND HEARD A NOISE AND NOTICED THE JACK NUT HAS PLAY/MOVEMENT IN JACKSCREW ASSY BASE.