ACE AVIATION SERVICES CORPORATION

Operated by Ace Aviation Services (per NTSB report)

Corrosion of both engines’ variable geometry (VG) system components, which led to their operation in an off-schedule position and resulted in near-simultaneous sub-idle rotating compressor stalls on approach, subsequent loss of thrust in both engines, and an off-airport landing. Contributing to the accident was inadequate fault isolation guidance from the engine manufacturer, which prevented the identification of corrosion buildup in VG system components during troubleshooting of hung start events of both engines about 1 month before the accident.

Part: OIL SYSTEM — LOW PRESSURE (RT ENGINE) · airframe 8,382 hrs · 6,647 cycles

DURING CLIMB OUT OF KFXE, R/H ENGINE OIL PRESSURE LIGHT ILLUMINATED AND OIL PRESSURE DROPPED TO ZERO. PILOT IMMEDIATELY SHUTDOWN ENGINE AND RETURNED TO HOMEBASE. AIRCRAFT RETURNED TO BASE LANDING 450 LBS OVER WEIGHT LIMITATIONS. POST FLIGHT INSPECTION REVEALED OIL STREAKS ON R/H ENGINE AND COWLING. TROUBLESHOOTING REVEALED CREW FROM PREVIOUS FLIGHT, AFTER SERVICING ENGINE OIL, DID NOT SECURE OIL CAP.

Part: THROTTLE — FAULTED

DURING THE FIELD ACCIDENT INVESTIGATION FOR N823KD CL604 S/N 5584, IT WAS MENTIONED THAT SEVERAL YEARS AGO A CHALLENGER 600 SERIES, DURING TAXI ACROSS AN ACTIVE RUNWAY, HAD A DUAL ENGINE FAILURE CAUSED BY THE AUTO THROTTLE SYSTEM. IN AN INTERNAL INVESTIGATION, TO TEST THAT THEORY, A RECENT SIMULATION WAS PERFORMED ON A CL-604 WITH THE SAFEFLIGHT ENHANCED AUTOPOWER AUTO THROTTLE SYSTEM INSTALLED WITH STC SA8191NM-D AND THROTTLE QUADRANT P/N C88627-1. THE TEST WAS PERFORMED TO SEE IF, WHEN THE THROTTLE LEVER CUTOFF SWITCHES WERE UNLATCHED, THE AUTO THROTTLE WOULD DRIVE TO CUTOFF POSITION EFFECTIVELY SHUTTING DOWN BOTH ENGINES. IT WAS CONFIRMED THE AUTO THROTTLE DOES DRIVE PAST THE IDLE GATE TO THE CUTOFF POSITION

Part: RELAY — BURNED OUT (WINDSHIELD DEFOG) · airframe 7,261 hrs · 4,871 cycles

DURING FLIGHT, PILOT INTERMITTENTLY SMELLED SMOKE IN THE AFT CABIN AREA WITH PASSENGERS ONBOARD. THE RIGHT WINDSHIELD DEFOG THEN BECAME INOPERATIVE, AND WAS SUBSEQUENTLY DEFERRED UPON LANDING. NO EMERGENCY WAS DECLARED. DURING MAINTENANCE TROUBLESHOOTING, THE WINDSHIELD DEFOG RELAY BOX WAS FOUND TO HAVE A HEAVY BURNED SMELL WITH VISIBLE SIGNS OF OVERHEATING. THE WINDSHIELD DEFOG RELAY BOX WAS REPLACED WITH NO FURTHER DISCREPANCIES NOTED.

Part: HOSE — UNSERVICEABLE (ZONE 700) · airframe 5,341 hrs · 3,641 cycles

ON INITIAL CLIMB OUT OF KFXE TO KOPF AT 1000 FEET, ENCOUNTERED LOSS OF HYDRAULIC PRESSURE. DECLARED EMERGENCY AND DIVERTED TO LONGER RUNWAY AT KMIA. UPON LANDING BRAKE AIR WAS UTILIZED. WITH NO PASSENGERS ONBOARD, DEPLANED AND ROUTED TO FBO WITHOUT INCIDENT. MAINTENANCE DETERMINED SOURCE TO BE R/H MLG RETRACT HOSE WAS LEAKING. REPLACED R/H MLG RETRACT HOSE AND BOTH ENGINE DRIVEN HYDRAULIC PUMPS AND FERRIED AIRCRAFT TO KFXE. INSPECTED HYDRAULIC FILTERS AND PRESSURE INDICATOR WITH NO DEFECTS NOTED, REPLACED #1 AND #3 HYDRAULIC BRAKE FUSES, SERVICED HYDRAULIC SYSTEM AND EMERGENCY AIR SYSTEM, AND PERFORMED GEAR RETRACTIONS AND BLEED CHECKS AT HOMEBASE.

Part: BRAKE DISC — TORN (ZONE 700) · airframe 9,191 hrs · 4,091 cycles

DURING SCHEDULED INSPECTION, KEY WAYS ON L/H INBOARD BRAKE ASSEMBLY FOUND CRACKED AND TORN OFF OF INBOARD BRAKE DISC.

Part: SKIN SPLICE — CORRODED (ZONE 100) · airframe 11,830 hrs · 11,709 cycles

AT SCHEDULED INSPECTION, UPON REMOVAL OF LOWER FORWARD WING ACCESS PANEL, DISCOVERED LOWER FORWARD WING SPLICE CORRODED AT F.S 384, B.L. 10L-10R BEYOND ALLOWABLE LIMITATIONS PER THE LEARJET 45 STRUCTURAL REPAIR MANUAL.

Part: SEAT TRACK — CORRODED (FS599) · airframe 6,838 hrs · 4,113 cycles

AT SCHEDULE INSPECTION, DISCOVERED SEAT RAIL UNDER LAVATORY TOILET CORRODED. REPLACED FLOOR RAIL WITH NEW.

Part: PANEL — CRACKED (ZONE 100) · airframe 7,355 hrs · 5,857 cycles

AT SCHEDULED INSPECTION, UPON KEEL BEAM PANEL REMOVAL, DISCOVERED PANEL MATING SURFACE ANGLE CRACKED AT LEFT END OF FORWARD PANEL MATING SURFACE ANGLE. DAMAGED AREA WAS REMOVED, FILLER AND DOUBLER INSTALLED, WORK PERFORMED IN REFERENCE TO FAA APPROVED DATA, FAA FORM 8110-3, AVIATION ENGINEERING CONSULTANTS E.O. 22-1683-01-01, REV. 0, DATED 2022-07-08, DERT-230212-CE.

Part: FLAP — DENTED (ZONE 500) · airframe 7,981 hrs · 5,675 cycles

AT POST FLIGHT INSPECTION, DISCOVERED DENT IN LEFT FLAP LOWER SKIN. PAINT WAS REMOVED, INSPECTED, DETERMINED NO SHARP CREASES, PASSED EDDY CURRENT INSPECTION, DENT FILLED WITH AEROSPACE PUTTY EPOXY CMO480007. REPAIRED PER FAA DER APPROVED DATA.

Part: WEB — CRACKED (ZONE 100) · airframe 4,166 hrs · 2,816 cycles

DURING SCHEDULED INSPECTION, DISCOVERED 1.5 INCH CRACK RUNNING LONGITUDINALLY ON RIGHT SIDE OF NOSE LANDING GEAR WHEEL WELL THROUGH EXISTING FASTENER HOLES, START AND STOP. CRACK LOCATION WAS OUTSIDE THE PRESSURE VESSEL. DAMAGE AREA WAS REMOVED AND ALUMINUM FLUSH PATCH INSTALLED PER FAA DER APPROVED DATA.

Part: WEB — CRACKED (FS 78.00) · airframe 6,691 hrs · 4,599 cycles

DURING SCHEDULED INSPECTION, DISCOVERED TWO INCH CRACK RUNNING LONGITUDINALLY ON RIGHT SIDE OF NOSE LANDING GEAR WHEEL WELL THROUGH EXISTING FASTENER HOLE. CRACK LOCATION WAS OUTSIDE THE PRESSURE VESSEL. DAMAGE AREA WAS REMOVED AND ALUMINUM FLUSH PATCH INSTALLED PER FAA DER APPROVED DATA.

Part: SEAT TRACK — CORRODED (BS 574-605) · airframe 5,694 hrs · 3,395 cycles

AT SCHEDULED INSPECTION, DISCOVERED CORROSION ON SEAT RAIL BEAM UPPER SURFACE, FS574.00 TO 605.00, WL73.5. CORROSION WAS REMOVED. DOUBLER REPAIR ANGLES OF 0.063 IN. 2024-T3 WERE INSTALLED WET USING MS20426AD RIVETS AND HL18PB5 HILOKS. REPAIR PERFORMED PER FAA APPROVED DATA IN DRAWING HAJ-GEBD604-5653-M04, REV. I/R FROM FAA DER DERT-605388-NM.

Part: SEAT TRACK — CORRODED (BS 574-605) · airframe 5,694 hrs · 3,395 cycles

AT SCHEDULED INSPECTION, DISCOVERED CORROSION ON SEAT RAIL BEAM UPPER SURFACE, FS574.00 TO 605.00, WL73.5. CORROSION WAS REMOVED. DOUBLER REPAIR ANGLES OF 0.063 IN. 2024-T3 WERE INSTALLED WET USING MS20426AD RIVETS AND HL18PB5 HILOKS. REPAIR PERFORMED PER FAA APPROVED DATA IN DRAWING HAJ-GEBD604-5653-M04, REV. I/R FROM FAA DER DERT-605388-NM.

Part: B-NUT — CRACKED (HYD LINE) · airframe 5,065 hrs · 3,974 cycles

ON APPROACH TO DAL, SELECTED FLAPS 20 AND GEAR DOWN. WHILE FLAPS AND GEAR WERE MOVING ENCOUNTERED HYDRAULIC PRESSURE LOSS. DECLARED EMERGENCY AND DIVERTED TO LONGER RUNWAY AT DFW. UPON LANDING EMERGENCY BRAKE AIR WAS UTILIZED. PASSENGERS DEPLANED AND ROUTED TO FBO WITHOUT INJURY. AIRCRAFT WAS TOWED OFF RUNWAY. MAINTENANCE DETERMINED HYDRAULIC PRESSURE TUBE CRACKED AT B-NUT FLANGE. TUBING WAS REPLACED, LEFT & RIGHT ENGINE DRIVEN HYDRAULIC PUMPS REPLACED, HYDRAULIC FILTER BYPASS INDICATOR DID NOT DEPLOY (REMAINED FLUSH). FILTER HOUSING ASSEMBLIES WERE CLEANED DUE TO LEAKING. HYDRAULIC SYSTEM WAS FLUSHED AND LEAK CHECKED. EMERGENCY AIR WAS SERVICED.

Part: SKIN — CORRODED (BS 228-330) · airframe 5,276 hrs · 3,433 cycles

AT SCHEDULED 12 YEAR INSPECTION, DISCOVERED CORROSION ON FUSELAGE SKIN AT LAVATORY SERVICE PORTS. CORROSION WAS REMOVED. REMAINING SKIN THICKNESS DETERMINED TO BE OUR OF LIMITS. REMOVED DAMAGED AREA. INSTALLED FILLER OF 0.040 INCH THICK 2024-T3 ALUMINUM AND EXTERNAL DOUBLER OF 0.050 INCH THICK 2024-T3 ALUMINUM. REPAIR INSTALLED HYSOL EA 9396 STRUCTURAL ADHESIVE AND FASTENERS, “WET” WITH PRC 890 CLASS B (AMD-S-8802) SEALANT. REPAIR PERFORMED PER FAA APPROVED DATA IN FAA DER DRAWING HAJ-LEAR60-352-M01, DATED MAY 25, 2021.

Part: DOOR — CRACKED (ZONE 100) · airframe 13,976 hrs · 9,685 cycles

GROUND DAMAGE; MAIN ENTRANCE DOOR, LOWER. AFT CORNER AT UPPER SEAM (STOWED) DENTED AND CRACKED. DAMAGE AREA 1.5 INCHES BY 2.0 INCHES. SKIN DENT WORKED SMOOTH; DAMAGED AREA REMOVED. EDDY CURRENT INSPECTION PERFORMED AROUND REMOVED AREA VERIFIED NO FURTHER DAMAGE. A FILLER AND DOUBLER SHEET METAL REPAIR WAS INSTALLED PER FAA DER APPROVED DATA.

Part: SKIN — HANDLER ERROR (ZONE 100) · airframe 3,826 hrs · 2,556 cycles

GROUND HANDLING DAMAGE; TWO SKIN PUNCTURES ON RIGHT SIDE OF FUSELAGE BETWEEN FS234.19 AND FS263.59. DAMAGE AREAS WERE REMOVED AND DOUBLER INSTALLED OF ONE SIZE THICKER ENCOMPASSING BOTH DAMAGED AREAS EXTENDING TWO FASTENERS BEYOND DAMAGE AREAS. REPAIR PER FAA DER APPROVED DATA.

Part: SKIN — DENTED (FUSELAGE) · airframe 4,943 hrs · 2,874 cycles

AT SCHEDULED INSPECTION, DISCOVERED DENT IN FUSELAGE BELLY SKIN AT FS 646 FRAME 640, TEN INCHES FROM CENTER. DAMAGE DIMENSIONS APPROXIMATELY 3.0 X 8.3. FASTENERS WERE REMOVED IN AREA, SKIN AND STRAP MECHANICALLY FORMED BACK TO ORIGINAL CONTOUR. REFORMED AREA VERIFIED NOT TO BE CRACKED, PER EDDY CURRENT INSPECTION METHOD. BENT SECTION OF FRAME 640 WAS REMOVED, FILLER WAS INSTALLED SANDWICHED BETWEEN TWO REINFORCEMENT DOUBLERS. DOUBLER REPAIR EXTENDING FIVE ROWS OF RIVETS BEYOND SEAM WAS PERFORMED PER STRUCTURAL REPAIR MANUAL 51-70-12, FIGURE 2, SHEET 2.

Part: SKIN — CHAFED (RT WING LE) · airframe 10,147 hrs · 10,333 cycles

AT SCHEDULED INSPECTION DISCOVERED RIGHT WING LEADING EDGE TO HAVE CHAFE DAMAGE, SCUFF MARKS BLENDED OUT. REMAINING MATERIAL THICKNESS DETERMINED TO BE APPROVED FOR CONTINUED SERVICE BY FAA DER, DERT-405106-CE.

Part: WINDSHIELD — CRACKED (COCKPIT) · airframe 10,091 hrs · 10,290 cycles

SHORTLY AFTER CLIMBING THROUGH 10,000 FEET THE RIGHT WINDSHIELD CRACKED. LEVELED OFF AT 10,800 FEET AND REQUESTED DESCEND TO 10,000 FEET. THE INNER LAYER WAS STILL SOLID AND ALL OTHER SYSTEMS WERE WORKING NORMALLY. CONTINUED TO DESTINATION WITHOUT FURTHER INCIDENT. WINDSHIELD REPLACED WITH NEW.

Part: PIN — MISSING (TORQUE LINK) · airframe 4,222 hrs · 2,412 cycles

AT SCHEDULED INSPECTION DETERMINED NOSE LANDING GEAR UPPER TORQUE LING ATTACHMENT TO LOWER TORQUE LING CASTELLATED NUT MIGRATING OUTWARD OFF OF TORQUE LINK APEX PIN DUE TO SECURING PIN MISSING. INSPECTED OPPOSITE PIN AND DETERMINED EXISTING PIN TO BE WORN. NO DAMAGE TO APEX PIN OR NUT. REPLACED EXISTING PIN AND MISSING PIN WITH NEW.

Part: STRUCTURE — CORRODED (CARGO DOOR) · airframe 6,498 hrs · 4,745 cycles

AT SCHEDULED INSPECTION DISCOVERED CORROSION ON BAGGAGE DOOR AROUND LATCHES AND KEYHOLE. REMOVED CORROSION AND DETERMINED REMAINING THICKNESS PER ULTRASONIC INSPECTION. REMAINING THICKNESS ACCEPTABLE.

Part: SKIN PANEL — CORRODED (BS 396) · airframe 6,498 hrs · 4,745 cycles

AT SCHEDULED INSPECTION DISCOVERED CORROSION FORWARD OF PANEL 510AL. REMOVED CORROSION. DETERMINED REMAINING THICKNESS BY ULTRASONIC INSPECTION. REMAINING THICKNESS DETERMINED TO BE ACCEPTABLE.

Part: SKIN — CORRODED (BS 396) · airframe 6,498 hrs · 4,745 cycles

AT SCHEDULED INSPECTION DISCOVERED CORROSION ON SKIN AFT OF LEFT MAIN LANDING GEAR WELL. REMOVED CORROSION AND DETERMINED REMAINING THICKNESS PER ULTRASONIC INSPECTION. REMAINING THICKNESS ACCEPTABLE PER FAA DER.

Part: SKIN — CORRODED (BS 245-256) · airframe 6,497 hrs · 4,745 cycles

AT INSPECTION DETERMINED SKIN CORROSION AT UPPER FORWARD TCAS ANTENNA. REMOVED CORROSION AND DETERMINED REMAINING THICKNESS PER ULTRASONIC INSPECTION. REMAINING THICKNESS ACCEPTABLE.

Part: BUSHING — MISSING (CONTROL WHEEL) · airframe 6,361 hrs · 4,632 cycles

WHILE INVESTIGATING PILOT REPORT OF LEFT / RIGHT AND FORWARD PLAY, DETERMINED CONTROL WHEEL DRUM BEARING (P/N MS27646-43) TO BE WORN. UPON FURTHER INVESTIGATION, DETERMINED BEARING WEAR RESULTING OF MISSING CONTROL WHEEL DRUM BUSHINGS (P/N'S 4527102086-003 AND 4527302001V32-003) ALLOWING SUFFICIENT GAP FOR ANGULAR AXIAL LOADS TO BE APPLIED ON RADIAL BEARING. BUSHINGS INSTALLED AND BEARING REPLACED.

Part: FAIRING — CORRODED (VERTICAL STAB) · airframe 9,554 hrs · 9,872 cycles

AFTER PAINT STRIPPING PROCESS DETERMINED VERTICAL STABILIZER TOP AFT FAIRING TO BE CORRODED. CORROSION WAS REMOVED AND DOUBLER REPAIR INSTALLED PER APPROVED DATA IN FAA DER DRAWING.

Part: SKIN — CORRODED (RT WING)

AT PAINT POST STRIPPING INSPECTION DETERMINED THE BELOW LISTED AREAS WERE CORRODED. CORROSION REMOVED AND DETERMINED BEYOND MANUFACTURES RECOMMENDATION.

Part: SKIN — CORRODED (FUSELAGE) · airframe 9,554 hrs · 9,872 cycles

AT PAINT POST STRIPPING INSPECTION DETERMINED THE BELOW LISTED AREAS ON SKINS WERE CORRODED. CORROSION REMOVED AND DETERMINED BEYOND MANUFACTURES RECOMMENDATION.

Part: SKIN — CORRODED (RT AILERON) · airframe 9,554 hrs · 9,872 cycles

AT PAINT POST STRIPPING INSPECTION, DETERMINED RIGHT AILERON LEADING EDGE SKIN TO BE CORRODED. LEADING EDGE SKIN REPLACED WITH FABRICATED SKIN OF 0.040 2024-T42 ALUMINUM.

Part: SKIN — CORRODED (THRUST REVERSER) · airframe 9,554 hrs · 9,872 cycles

AT POST PAINT INSPECTION, DETERMINED RIGHT THRUST REVERSER LOWER SKIN TO BE CORRODED. SKIN REPLACED WITH ONE FABRICATED PER APPROVED FAA DER DRAWING.

Part: SKIN — CORRODED (THRUST REVERSER) · airframe 9,554 hrs · 9,872 cycles

AT PAINT POST STRIPPING INSPECTION, DETERMINED RIGHT THRUST REVERSER UPPER SKIN TO BE CORRODED. SKIN REPLACED WITH ONE FABRICATED PER APPROVED DATA IN FAA DER DRAWING.

Part: STRINGER — CORRODED (FUSELAGE) · corrosion level 2 · airframe 12,459 hrs · 8,634 cycles

AT SCHEDULED INSPECTION, DETERMINED STRINGER 21, BETWEEN FS 151.9 AND FS 176.59 TO BE CORRODED. DAMAGED STRINGER SECTION REMOVED, SKIN CLEANED AND INSPECTED AND STRINGER SPLICE REPAIR PERFORMED PER STRUCTURAL REPAIR MANUAL AND DER DRAWING.

Part: RIB — CRACKED (RUDDER) · airframe 12,459 hrs · 8,634 cycles

AT SCHEDULED INSPECTION, DISCOVERED RUDDER RIB AT WL 126.0 TO BE CRACKED. RIB REPAIRED WITH DOUBLER PER LEARJET 60 STRUCTURAL REPAIR MANUAL SECTION 55-40-01.

Part: AXLE — CORRODED (RT MLG) · airframe 12,459 hrs · 8,634 cycles

AT SCHEDULED INSPECTION, DETERMINED RIGHT MAIN LANDING GEAR AXLE CORRODED. REPLACED AXLE WITH NEW.

Part: TORQUE TUBE — CORRODED (RUDDER) · airframe 12,459 hrs · 8,634 cycles

AT SCHEDULED INSPECTION, DISCOVERED RUDDER TORQUE TUBE CORRODED. REPLACED RUDDER TORQUE TUBE WITH NEW.

Part: SKIN — CRACKED (RUDDER) · airframe 12,459 hrs · 8,634 cycles

AT SCHEDULED INSPECTION, DISCOVERED RUDDER LOWER LEADING EDGE SKIN CRACKED. REPLACED RUDDER LOWER LEADING EDGE SKIN.

Part: SUPPORT BRACKET — CRACKED (THRUST REVERSER) · airframe 12,459 hrs · 8,634 cycles

AT SCHEDULED INSPECTION, DISCOVERED RIGHT THRUST REVERSER OUTBOARD FORWARD FAIRING SUPPORT BRACKET. REPLACED SUPPORT BRACKET WITH NEW.

Part: BRACKET — CRACKED (THRUST REVERSER) · airframe 12,459 hrs · 8,634 cycles

AT SCHEDULED INSPECTION, DISCOVERED RIGHT THRUST REVERSER AFT STANG FAIRING BRACKET CRACKED. REPLACED RIGHT THRUST REVERESER STANG FAIRING AFT BRACKET.

Part: BRACKET — CRACKED (THRUST REVERSER) · airframe 12,459 hrs · 8,634 cycles

AT SCHEDULED INSPECTION, DISCOVERED LEFT THRUST REVERSER INBOARD STANG FAIRING AFT BRACKET CRACKED.

Part: SUPPORT ANGLE — CRACKED (LT AILERON) · airframe 12,459 hrs · 8,634 cycles

AT SCHEDULED INSPECTION, FOUND CRACK AT RIVET HOLE ON LEFT AILERON ANGLE SUPPORT AT AILERON STATION 32.0. PERFORMED DOUBLER REPAIR PER DER DRAWING.

Part: PLATE — CORRODED (PAX DOOR AREA) · airframe 3,240 hrs · 1,783 cycles

PASSENGER DOOR, FORWARD FRAME LOWER FITTING MOUNT FOR DOOR COUNTER BALANCE, SERRATED PLATE UNDER MOUNT CORRODED. SERRATED PLATE REPLACED.

Part: MOUNT — CORRODED (ASSIST CABLE) · airframe 3,240 hrs · 1,783 cycles

PASSENGER DOOR AFT FRAME AT BS 349, THE DOOR POWER ASSIST CABLE MOUNT WAS CORRODED. CABLE MOUNT WAS REPAIRED IAW DRAWING HAJ-GEBD604-5653-M01-1.

Part: SKIN — CORRODED (WINGS) · airframe 9,552 hrs · 9,869 cycles

CORROSION WAS DISCOVERED AT THE FOLLOWING LOCATIONS. CORROSION WAS MECHANICALLY CLEANED. CORROSION WAS BEYOND. MANUFACTURE ACCEPTED STRUCTURAL REPAIR MANUAL.

Part: ANGLE — CORRODED (BS 520) · airframe 9,552 hrs · 9,869 cycles

WHILE PERFORMING 9600 HOUR INSPECTION DISCOVERED LAND ANGLE AT BS 520 TO BE CORRODED. CORROSION WAS ON AFT SURFACE LOWER POSITION AND DETERMINED TO BE OUT OF LIMITS. OPEN

Part: RAIL — CORRODED (BS 520-580) · airframe 9,552 hrs · 9,869 cycles

WHILE PERFORMING 9600 HOUR INSPECTION, DISCOVERED RAIL ASSEMBLY BETWEEN BS 520 TO 580 TO BE CORRODED. CORROSION WAS FORWARD ON UPPER SURFACE AT THE ANGLE INTERFACE AND DETERMINED TO BE OUT OF LIMITS. OPEN

Part: SKIN — CORRODED (LT WING) · airframe 9,552 hrs · 9,869 cycles

WHILE PERFORMING 9600 HOUR INSPECTION, DETERMINED LEFT WING OUTBOARD LOWER SKIN UPPER SURFACE TO HAVE CORROSION AT WS 260. CORROSION DETERMINED OUT OF LIMITS. CORROSION CLEANED, SURFACE BLENDED, FILLED WITH EPOXY PASTE AND DOUBLER INSTALLED.

Part: SKIN — CORRODED (RT WING) · corrosion level 2 · airframe 9,552 hrs · 9,869 cycles

WHILE PERFORMING 9600 HOUR INSPECTION, DETERMINED RIGHT WING OUTBOARD LOWER SKIN UPPER SURFACE TO HAVE CORROSION AT WS 260 AT COVE SURFACE INTERFACE. CORROSION DETERMINED OUT OF LIMITS. CORROSION CLEANED, SURFACE BLENDED, FILLED WITH EPOXY PASTE AND DOUBLER INSTALLED.

Part: BOOT — SHORTED (HORIZONTAL STAB) · airframe 4,408 hrs · 3,581 cycles

ON GROUND AFTER FLIGHT AND PASSENGER DEBOARDED, BETWEEN FLIGHT, AFTER APPROXIMATELY 20 MINUTES, SAW SMOKE WAS COMING FROM THE LEADING EDGE OF THE RIGHT HORIZONTAL STABILIZER. CREW VERIFIED COCKPIT SWITCH TO BE IN OFF POSITION. CREW EXPELLED GROUND FIRE EXTINGUISHER ON STABILIZER BOOT. AIRPORT FIRE DEPARTMENT ARRIVED AND DOUSED BOOT WITH WATER. HORIZONTAL STABILIZER BOOT REPLACED.

Part: PACKING — LEAKING (PRESSURE SWITCH) · airframe 3,737 hrs · 2,467 cycles

DURING CRUISE AT FL410, OBSERVED THE AMBER LEFT LOW HYDRAULIC ANNUNCIATOR FLICKER FOLLOWED BY THE RIGHT. FLICKERED AGAIN A FEW TIMES THEN TURNED SOLID ON. THE HYDRAULIC PRESSURE GAUGE SHOWED NORMAL 1550 PSI. DETERMINED THAT THE HYDRAULIC PRESSURE GAUGE WAS VERY, VERY SLOWLY GOING DOWN MAYBE 50 PSI. DIVERTED DUE TO A HYDRAULIC ISSUE AND DECLARED AN EMERGENCY. LANDED WITHOUT INCIDENT. MAINTENANCE DISCOVERED HYDRAULIC LEAK AT THE RIGHT LOW PRESSURE SWITCH. THE PRESSURE SWITCH PACKING WAS REPLACED. SYSTEM VERIFIED NOT TO BE CONTAMINATED. ENGINE DRIVEN HYDRAULIC PUMPS REPLACED. SYSTEM OPS AND LEAK CHECKS PERFORMED. AIRCRAFT RETURNED TO SERVICE.