N634QX
Registered owner: HORIZON AIR INDUSTRIES INC, WA (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
No NTSB accidents or incidents on file for this aircraft.
Maintenance disclosures
FLAP TRACK FAIRING 2 OF THE RH INBOARD WING SUPPORT ON THE INBOARD SIDE EXCESSIVELY LOOSE. REMOVED FROM SERVICE. REMOVED RH INBOARD-FLAP TRACK FAIRING 2, REF E175 AMM 57-58-23-000-801-A. FOUND FWD INBD CLAMP BUSHING MISSING AT FAIRING FWD ATTACH POINT (SEE E175 IPC 57-58-0, FIG 3 SHEET 4 OF 4 ITEM 875). INTALLED MISSING FWD INBD CLAMP BUSHING AT FAIRING FWD ATTACH POINT (REF E175 IPC 57-58-00) & INSTALLED INBD-FLAP TRACK FAIRING 2 IAW E175 AMM TASK 57-58-23-400-801-A. RETURNED TO SERVICE,
HAIRLINE CRACK APPEARED IN CRUISE ON CAPTAIN SIDE WINDSHIELD STARTED TO SPLINTER INTO MULTIPLE BRANCHES, RAN QRH & DEPRESSURIZED ACFT. CRACK WENT AWAY. EMERENCY DIVERTED. LANDING UNEVENTFUL. REMOVED FROM SERVICE. PERFORMED GVI, TACTILE, & DETAILED INSPECTION OF INNER, CENTER & OUTER PLIES OF CAPTAINS COCKPIT WINDSHIELD. IAW AMM 56-11-00-210-801-A & SRM 56-11-00-01-01. NO DEFECTS NOTED, DELAMINATION OF CRACKS NOTED. PERFORMED CABIN PRESSURIZATION IAW AMM 21-31-00-720-802-A. PRESSURIZED TO 4.5 PSIG. . REPEATED WINDSHIELD DETAILED INSPECTION WHILE PRESSIZATED. NO DEFECTS, DELAMINATION OR CRACKES NOTED. PERFORMED DETAILED INSPECTION OF CAPTAINS WINDSHIELD WITH 10X POWER MAGNIFICATION GLASS, REF AMM 56-11-00-210-801-A AND SRM PART 2 56-11-00-01-01. NO DEFECTS, DELAMINATION OR CRACKS NOTED. REFERENCE AML 1140752 FOR OPS CHECK FLIGHT RELEASE. CHECK FLIGHT PASSED NO DEFECTS. RETURNED TO SERVICE.
IN FLIGHT THE ELEVATOR FEELS STUTTERY ALMOST AS IF IT'S CATCHING ON SOMETHING AS IT MOVES. DURING TH FLIGHT CONTROL CHECK ON THE GROUND IT FELS NORMAL, BUT WHEN TH FO TOOK OFF HE FELT IT AS SOON AS ROTATION AND IT CONTINUED FOR THE ENTIRE FLIGHT. BOTH WITH AUTOPILOT ON AND OFF AND BOTH THE CA AND FO SIDE WE COULD FEEL IT STUTTERING WHENEVER THE ELEVATORS CONTROLS WOULD MAKE A PITCH CHANGE.THE ELEVATOR WAS STILL FUNCTIONING, MAKING PITCH CHANGES WASN'T DIFFICULT. IT JUST DIDN'T FEEL NORMAL. REMOVED FROM SERVICE. REMOVED AND REPLACED FO'S SIDE CONTROL COLLUMN DAMPER REF E175 AMM TASK 27-31-02-000-801-A. OPS CK GOOD REF N/R-00001 W/O 361130 FOR WORK PERFORMED. RETURNED TO SERVICE.
AFT PASSENGER DOOR DIFFICULT TO ARM/ DISARM. REMOVED FROM SERVICE. REMOVED AFT SERVICE DOOR BUSTLE WITH LATCHES REF E175 AMM TASK 25-23-07-000-801-A PARA 7J. ADJUSTED AFT GIRT BAR FLOOR FITTING REF E175 AMM MCN E520132-01. DOOR ARMING LEVER CHECKS GOOD. INSTALLED R2 DOOR BUSTLE IAW E175 AMM TASK 25-23-07-400-801-A PAR 6K. RETURNED TO SERVICE. NO PARTS REPLACED.
RIGHT SEAT TRACK AT FRAME 74-84 HAS CORROSION IN MULTIPLE SPOTS INCLUDING THE END AT FRAME 84. LOCAL LEVEL CPCP LEVEL 2. OUT OF LIMITS IN SRM 53-23-10 FIGURE 101. REPLACED THE SEAT TRACK IAW SRM 51-40-08 AND TC 170-00677.
RIGHT WING FIXED LEADING EDGE AT NR 3 SLAT IS DENTED AND GOUGED. CUT OUT THE DAMAGED AREA. FABRICATED AND INSTALLED DOUBLER. REPAIRED THE FIXED LEADING EDGE UND THE SLAT IAW ETD 2026-170-000702. TREATED PRIMED AND PAINTED THE AREA.
RIGHT LATERAL SEAT TRACK CHAFED AND MISSING PAINT. PERFORMED SPLICE REPAIR IAW SRM 53-00-10-02-02. ALODINED PRIMERED AND APPLIED TOP COAT TO REPAIR.
FLIGHT 2103. R1 DOOR SLIDE INDICATOR, CENTER, BLANK IN BOTH OPEN AND CLOSED POSITIONS. REMOVED FROM SERVICE. PLACED ON MEL 52-70-01C. MEL CLEARED BY PERFORMING MCN E520141-01 ISSUE 1, WHILE REINSTALLING UPPER LINER FOUND SUPPORT BRACKET ON LINER SLIGHLTY BENT. REF W/O 358089 N/R-00006 FOR WORK PERFORMED. PERFORMED GVI OF BRACKET FOUND NO CRACKS. BENT BACK INTO CORRECT POSITION AS REQUIRED. ARMED & UNARMED INDICATOR NOW ALIGNED WITH VIEWING WINDOW CONE. PLACARDS PULLED. MTX CONTROL NOTIFIED. THIS CLEARS DEFECT.
EMERGENCY FLOOR LIGHTING STRIP SEPARATED FROM TRACK. REMOVED FROM SERVICE. REPLACED ADHESIVE BACKING ON PHOTOLUMINESCENT INDICATOR STRIP LIGHT REF AMM 33-50-21-000/400-801-A. OPS CHECK GOOD. RETURNED TO SERVICE.
R1 DOOR MISSING MULITPLE PLACARDS. REMOVED FROM SERVICE. FOUND 4 MISSING PLACARDS ON R1 UPPER DOOR LINER. INSTALLED REQUIRED PLACARDS IAW AMM 20-10-09-400-801-A REF AIPC 11-32-03 FOR PLACEMENT AND CORRECT PLACARDS. ACFT OK FOR SERVICE. MISSING PLACARDS WERE N,F,D,C. SLIDE DISARM AND SLIDE INDICATION, DOOR OPENING INSTRUCTIONS, AND "OPEN" PLACARD.
FLIGHT 2067. BURNING SMELL IN AFT GALLEY, FOLLOWED BY RH RECIRC FAN REMOTE CB TRIP. PLACED ON MEL AND RETURNED TO SERVICE. MEL CLEARED 8/10 BY REPLACING RH RECIRC. FAN IAW AMM 21-24-01-000/400-801-A. OPS CHECK GOOD. MTX PROCUDRES REVERSED & PLACARDS REMOVED. CLEAR MEL. RETURNED TO SERVICE.
FLIGHT 2084. ON TAKEOFF ROLL AFTER 80 KIAS, ENGINE PERFORMANCE VALUES BEGAN DROPPING. HIGH-SPEED REJECTED TAKEOFF EXECUTED. RETURNED TO GATE REMOVED FROM SERVICE. CW POWER ASSURANCE RUN FOR BOTH ENGINES IAW GE LMM TASK 72-00-00-700-802 SUBTASK 72-00-00-760-043. ALL PARAMENTERS ARE WITHIN LIMITS, N1 TARGETS WERE MET. RETURNED TO SERVICE. NO PARTS REPLACED.
RAMP REPORTED SMOKE COMING FROM THE BACK OF #2 ENGINE SHOIRTLY AFTER SHUTDOWN. REMOVED FROM SERVICE. PERFORMED GVI OF #2 ENGINE AND FOUND NO DEFECTS. PERFORMED ENGINE RUN AND FOUND NO DEFECTS. NO SMOKE COMING FROM #2 ENGINE UPON SHUTDOWN. NO FURTHER DEFECTS NOTED. RETURNED TO SERVICE. NO PARTS REPLACED.
AFT GALLEY CENTER EMERGENCY EXIT LIGHT INOP. REMOVED FROM SERVICE. REMOVED AND REPLACED THE AFT UPPER EMERGENCY LIGHT POWER UNIT REF E175 AMM 33-50-01-000-801-A AND 33-50-01-400-801-A. REF E175 AMM 33-50-01-000-802-A AND 33-50-01-400-802-A FOR EMERGENCY LIGHT UNIT BATTERY REMOVAL AND INSTALLATION. OPERATIONAL CHECK GOOD. RETURNED TO SERVICE.
FLT CTRL NO DISPATCH ON EICAS DURING CAPT FLIGHT CONTROL CHECK AFTER ENGINE START.FOUND FAULTS 27030378FCS & 22110198PB2. REMOVED FROM SERVICE. R+R P-ACE #1 REF. E175 AMM 27-03-03-000/400-801-A. NO HELP. WHEN TROUBLESHOOTING A FCND, FOUND LH ELEVATOR OB LVDT BRACKET (ON ELEVATOR SIDE) BROKEN.R/R LH ELEVATOR OB LVDT BRACKET IAW W/O 346784 EA ETD2024-170-900413/1. NO FURTHER DEFECTS NOTED. WHEN TROUBLESHOOTING A FCND, FOUND LH ELEVATOR OB LVDT AFT BEARING SEIZED.REMOVED LH ELEVATOR LVDT (OB) IAW E175 AMM 27-33-02-000-801-A. JP 1076525. INSTALLED SERVICEABLE FROM STOCK LH ELEVATOR O/B LVDT IAW E175 AMM 2P7-33-02-400-801-A. OPS CHECK/RIGGING GOOD. A/C OK FOR SERVICE.
FLIGHT 2061. ENG 1 REV FAIL CAUTION ON LANDING. REMOVED FROM SERVICE AND PLACED ON MEL 78-30-00D. RETURNED TO SERVICE. MEL CLEARED 9/18 BY INTEROGATED CMC & FOUND FC: 73217627E1B & 73217627E1A. PER FIM 73-21-00-810-81B-A REPLACED TQC ASSY (REF AMM 76-11-01-00-801-A & 76-11-01-400-801-A). OPS TEST GOOD, NFDN. RETURNED TO SERVICE.
TAIL STRIKE DURING BALKED LANDING AND GO AROUND. REMOVED FROM SERVICE. APU FWD ACCESS PANEL (351GL) HAS DAMAGE FROM TAIL STRIKE CONTACT. APU AFT ACCESS PANEL (351HL) HAS DAMAGE FROM TAIL STRIKE CONTACT. FWD BOTTOM EDGE OF APU TAILCONE HAS DAMAGE FROM TAIL STRIKE CONTACT. PHASE II HARD LANDING INSPECTION REQUIRED; C/W E175 AMM TASK 05-50-03-200-802-A. APU INLET SILENCER REQUIRES REPLACEMENT DUE TO DIFFUSER SPLITTER VANE DAMAGE BEING OUT OF LIMITS PER AMM TASK 49-16-01-350-801-1. AIRCRAFT DOWN FOR REPAIRS.
#1 ENGINE FUEL IS LEAKING FROM FMU. R&R #1 ENG FMU REF E175 AMM 73-21-03-400/000-801-A. OPS CHECK GOOD. LEAK CHECK GOOD.
R2 DOOR RED UP ARROW PARTIALLY MISSING. REMOVED FROM SERVICE. REMOVED & REPLACED PLACARD REF TO MCN E110019-01. RETURNED TO SERVICE.
POST FLIGHT NOTICED WHITE SMOKE #2 ENG STRONG SMELL JET FUEL. REMOVED FROM SERVICE. FOUND 2.5â DIA OIL IN THE CHEVRON NOZZLE, CLEANED OIL PUDDLE. WITH CREW ASSISTANCE PERFORMED #2 ENG START/RUN INSPECTED AFTER SHUT DOWN, ALL CONDITIONS NORMAL, SMOKE NO LONGER PRESENT. OIL LEVEL INDICATIONS OK REF IAW AMM 12-13-01-200-801-A. RETURNED TO SERVICE.
AFTER APPLYING POWER FOR TAKEOFF AN UNPLEASANT ODOR STARTED IN THE VENT SYSTEM ADN BECAME STOREST AT 500' BEFORE IT COMPLETLY WENT DISSAPPEARED BY 10,000". REMOVED FROM SERVICE. C/W E175 FIM TASK 21-20-00-810-801-A RAN A/C FOR 15 MIN WITH NO ADNORMAL SMELLS NOTED. ALSO REF MCN E210016-3, A/C OK FOR CONTINUED SERVICE.
PHOTOLLUMINESCENT STRIP PEELING UP AT ROW 1. REMOVED FROM SERVICE. CLEANED AND RESECURED PHOTOLLUMINESCENT STRIP AT ROW 1 REF E175 AMM 35-50-21-400-801-A. NO FURTHER DEFECTS NOTED. RETURNED TO SERVICE.
R2 DOOR WILL NOT INDICATE DISARMED AND WILL NOT ARM. REMOVED FROM SERVICE. BELIEVED TO BE ICE. DOOR OPERATED NORMALLY AFTER 15 MIN ON GROUND. IND ARM AND DISARMED NORMALLY. RETURNED TO SERVICE.
FIRST PHOTOLUMINESCENT STRIP ON STARBOAD SIDE OF AISLE NEAR FORWARD GALLY IS LOOSE. REMOVED FROM SERVICE. RESCURED PHOTOLUMINESCENT STRIP AT SEAT 1 D,C NO FUTHER DEFECTS NOTED. RETURNED TO SERVICE.
EXIT IDENTIFIER LIGHT ON FORWARD LAVATORY AFT WALL IS INOPERATIVE. REMOVED AND REPLACED #6 FUSE ON EMERGENCY LIGHT POWER UNIT #2 PER DIEHL CMM 33-50-01.
FR 90 CROSSBEAM AT INTERSECTION OF RH LONGITUDINAL BEAM HAS CORROSION. REMOVED AND REPLACED FR 90 CROSSBEAM AT INTERSECTION OF RH LONGITUDINAL BEAM REF SRM 51-40-08.
RH UPPER SHEET JUST FORWARD OF FR 86 HAS CORROSION. REMOVED AND REPLACE RH UPPER SHEET JUST FORWARD OF FR 86 PER SRM 51-40-08, RESTORED SURFACE PROTECTION PER SRM 51-23-06.
FWD PASSENGER DOOR EXIT PLACARD FADED. APPLIED FWD PASSENGER DOOR EXIT PLACARD AMM 20-10-09.
FORWARD SERVICE DOOR SURROUND EMERGENCY LIGHT HAS ONE QUICK DISCONNECT CONNECTOR THAT HAS PULLED FROM THE WIRE. CONNECTOR PN 48-7191 PIN PN M39029/31-228.:REPAIRED QUICK DISCONNECT SPLICE AT FORWARD SERVICE DOOR EMERGENCY LIGHT REF SWPM 20-41-20 AND OPS CHECKED GOOD REF AMM 33-50-00.
R1 DOOR SLIDE PRESSURE GUAGE IS OUTSIDE OF THE GREEN ARC. REMOVED FROM SERVICE. REPLACED THE R1 DOOR SLIDE ASSY WITH A SERVICEABLE DOOR SLIDE ASSY. RETURNED TO SERVICE.
FA REPORTS CHEMICAL SMELL AND SOAPY WATER IN BOTH GALLEY AND LAVS. NO SPECIFIC ODOR. MADE THEM COUGH AND CHOKE. POTABLE WATER ISSUE. REMOVED FROM SERVICE. FLUSHED POTABLE WATER SMELL CLEARED NO OTHER DEFECTS NOTED. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.
EMERGENCY LANDING GEAR DOOR ON FLIGHT DECK FLOOR IS VERY DIFFICULT TO OPEN. REMOVED FROM SERVICE. OPENED DOOR AND CLEANED STICKY DEBRIS FROM DOOR SILL AND DOOR EDGE. LUBRICATED DETENT BALL WITH LPS-1. DOOR OPENS AND CLOSES NORMALLY WITH EASE. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.
THRUST LEVERS SPLIT AND ENG 2 MAX TOT, CHL, CLET TURNED RED. THEN NORMALIZED LP EN1. 1V/B WAS LP ENG2 V/B. RETURNED TO FIELD, LANDING UNEVENTFUL. REMOVED FROM SERVICE. INTERROGATED CMC FOR FAULTS/EXCRESCENCES. NO FAULTS OR EXCRESCENCES NOTED. PERFORMED ACMF AND FHDB DOWNLOAD IN REFERENCE WITH E175 AMM TASK 45-45-00-970-801A AND MCN NO: E450009-01 ISSUE NO: 1. HORIZON PROPULSION ENGINEERING REVIEWED ACMF DATA., NO RELATED DATA SHOWN. FHDB DOWNLOAD SHOWS NO MTX MESSAGES POSTED DURING LAST FLIGHT. RETURNED TO SERVICE.
WHEN BEACON SWITCH TURNED ON, TURNING ON BOTH BEACONS, BURNING SMELL WAS NOTED. REMOVED FROM SERVICE. DETACHED LIGHTING PANEL WITHOUT DISCONNECTING, INSPECTED BEACON SWITCH FOUND NO OBVIOUS DEFECT, NO BURNING NOTED AND NO HEAT INDICATION OF WIRING OR SWITCH NOTED. RE SECURED LIGHTING PANEL. UPPER BEACON LIGHT WORKING NORMAL, LOWER BEACON LIGHT ON DEFERRAL REF LP 951803.
AFTER TURNING RED BEACON FOR PUSHBACK SMELLED SOMETHING BURNING BUT COULDN'T BE SURE. DURING PUSHBACK COULD STILL SMELL SOMETHING SO IT WASN'T FROM THE PUSHBACK CART. THEN RAMP INFORMED US THE BOTTOM AND TOP RED BEACON WASN'T WORKING . TRIED CYCLING BEACON SWITCH A FEW TIMES NO CHANGES. AFTER PARKING AT GATE TRIED THE BEACON SWITCH AGAIN AND COULD SEE IN TERMINAL WINDOW REFLECTION TOP BEACON WORKING. PLACED ON MEL. REMOVED PANEL 192CR TO GAIN ACCESS TO THE LOWER RED BEACON POWER SUPPLY & PERFORMED GVI WITH NO DEFECTS NOTED. PERFORMED OPS TEST OF THE RED BEACON LIGHTS IAW E175 AMM 33-45-00-710-801-A FOR 15 MINUTES WITH A TECH BY THE LOWER BEACON POWER SUPPLY, A TECH IN THE FLIGHT DECK AND A TECH IN THE FWD EBAY. OPS TEST OF BOTH RED BEACON LIGHTS GOOD, NO ODORS NOTED IN ANY AREA. CLOSED THE FWD EBAY AND REINSTALLED PANEL 192CR. THIS CLEARS DEFECT 951803, ASSOCIATED DEFERRAL PLACARDS REMOVED. MTX CTRL NOTIFIED. RETURNED TO SERVICE.
DURRING FUEL QUANTITY HARNESS ROUTING INSPECTION FOUND INCORRECT ROUTING UNDER PANEL 195 AL. REROUTED GROUND SPOILER CONT MDL HARNESS SO THAT IT RAN SEPRATE FROM FQIS HARNESS TO COMPLY WITH INSPECTION CRITERIA IN E175 AMM 28-41-00-210-801-A.
GROUND CREW REPORTED L1 DOOR HARD TO CLOSE AND OPEN. REMOVED FROM SERVICE. FOUND DEBRIS IN L1 DOOR GIRT BAR TRACK, CLEANED DEBRIS AS REQUIRED. DOOR OPERATES NORMALLY. NO FURTHER DEFECTS NOTED. RETURNED TO SERVICE.
MILD FUMES IN CABIN APPROXIMATELY AT ROW 6 NOTED BY FA "A" AND PASSENGERS IN ROW DURING DESCENT. NO VISIBLE PLUME OBSERVED AND FAINT ODOR DETECTED BY THE FO AFTER LANDING. SMELL INCREASED PRIOR TO LANDNG WHEN GEAR EXTENDED TYPE 1 AND TYPE IV FLUID HAD BEEN APPLIED BACK IN FAI. EMERGENCY DECLARED. LANDING UNEVENTFUL. REMOVED FROM SERVICE. C/W FIM 21-20-00-810-801-A & FORM M-744. NO DEFECTS OR ABNORMAL SMELLS NOTED. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.
AUTOLAND UNSATISFACTOR AUTOPILOT DISENGAGED AT 8 FEET ABOVE RUNWAY. CA LANDED AIRCRAFT. DEFERRED RADAR ALTIMETER. CLEARED BY REPLACING NR 1 RADAR ALTIMETER UNIT, IAW E175 AMM TASK 34-31-01-000/400-801-A. OPERATIONS CHECK GOOD, AIRCRAFT IS CATEGORY III QUALIFIED COCKPIT PLACARD READ CAT III. RETURNED TO SERVICE.
MAINTENANCE FOUND THE FORWARD SERVICE DOOR HARD TO OPEN. CLEANED THE DOOR LATCH ASSEMBLY. PERFORMED OPERATIONAL TEST OF DOOR. CHECKS GOOD.
FA REPORTS FWD GALLEY OVEN INOP AND SMELLS.
AFTER USING FWD OVER FA SMELLED BURNING FROM OUTSIDE OVEN. TURNED OVEN OFF AND SMELL STOPPED. REMOVED FROM SERVICE. REMOVED OVEN IAW E175 AMM TASK 25-37-02-000-801-A, CLEANED DEBRIS FROM OVEN TOP, REINSTALLED OVEN IAW TASK 25-37-02-400-801-A, TURNED OVEN ON, ALLOWED TO WARM, AND NO UNUSUAL ODORS NOTED, RETURNED OVEN TO OFF POSITION. AIRCRAFT RETURNED TO SERVICE.
ON DEPARTURE #2 ENGINE LP VIB INDICATOR WENT TO 4.0 YELLOW CONDITION. QRH DIDN'T WORK, VIB INTENSIFIED. RETURNED TO FIELD. LANDING UNEVENTFUL. REMOVED FROM SERVICE. PERFORMED GVI OF #2 ENGINE - NO EVIDENCE OF BIRDSTRIKE OR FOD. OBSERVED FAN ROTOR TURNS FREELY AND ALL FAN BLADES MOVE FREELY. PERFORMED MCN E770001-01, ISSUE 2. DETERMINED ENGINE VIB TO BE "ABNORMAL" PERFORMED FIM TASK 77-31-00-810-816-A PAR 1-5F. NO FAULTS OR ENGINE CHIP NOTED IN CMC. COMPLIED WITH GE LMM TASK 72-00-00-810-803, SUBTASK 72-00-00-810-011. FLOWCHART DETERMINED GE LMM TASK 72-21-00-800-806 (SPECIAL PROCEDURE 097) IS REQUIRED. PLACED ON DEFERRAL TO BE ACCOMPLISHED WITHIN 50 HOURS.
WHILE CLIMBING (APPROX FL190) THE #2 ENGINE EXPERIENCED AN ELEVATED ENGINE VIBRATION. ENGINE VIBRATION INDICATED 4.0 W/ REVERSE VIDEO IN AMBER. THE ENGINE VIBRATION ABNORMAL CHECKLIST PROVIDED GUIDANCE TO REDUCE THRUST ON THE #2 ENGINE. VIBRATION WENT BACK TO GREEN INDICATION AT 3.6. POWER REMAINED STABILIZED NOT TO EXCEED 3.6 FOR THE REMAINDER OF THE FLIGHT. DECLARED EMERGENCY. REMOVED FROM SERVICE. DETERMINED TO BE ABNORMAL N1 VIBRATION PER E770001-01. C/W INSPECTIONS PER LMM 72-00-00-810-011. ALL BLADES MOVE FREELY, NO OTHER DEFECTS NOTED. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.
COCKPIT DOOR CONTROL CLICKS TWICE AND DOES NOT IMMEDIATELY UNLOCK DOOR (UNLOCKED BUTTON BLINKS ON) ( FLIGHT DECK SECURITY DOOR AUTOMATIC LOCKING SYSTEM ). CLEANED ELECTROMECHANICAL COCKPIT DOOR LOCK, LOCK NOW FUNCTIONS NORMALLY, UNLOCK BUTTON NO LONGER BLINKS ON. OP CHECK IS GOOD REF AMM TASK 52-51-03-820-801-A, THIS ACTION CLEARS DEFECT. PLACARDS REMOVED. MTX PROCEDURE REVERSED. MTX CNTRL NOTIFIED.