# JASC 5400: Nacelle/Pylon Structure - Type: JASC system/component code (FAA) - ATA chapter: 54 Nacelles/Pylons - Title in the code table: NACELLE/PYLON STRUCTURE - Service difficulty reports: 1,907 - FAA code table: https://www.faa.gov/sites/faa.gov/files/JASC_Code.pdf#page=49 - Page: https://openairdocs.org/jasc/5400 ## What it covers For reports of structural units and associated components and members which furnish a means of mounting and housing the powerplant or rotor assembly. Includes the structure of powerplant cowling inclusive of the structural portion of the inlet whether or not integral with the aircraft. Structural portions of the exhaust system are excluded where they are not integral with the airframe. Use this code when there is insufficient information to file in a more specific JASC 5400 series code. NOTE: The use of this code should be avoided if possible as a reported defect is not likely to involve both pylon and nacelle. ## Service difficulty reports (1,907, newest 50) - [SDR VNAA2026092425401](https://openairdocs.org/sdr/VNAA2026092425401), Sep 23, 2026: Cndair CL6002C10. DOOR. GOUGED. RIGHT UPPER COWLING LATCH BEAM GOUGED. PERFORMED REPAIR TO RT THRUST REVERSER LATCH BEAM USING STEPS AND DRAWINGS LISTED (N520DC) - [SDR CALA2026093020009](https://openairdocs.org/sdr/CALA2026093020009), Aug 30, 2026: Boeing 757224. DRAG FITTING. NOT REPORTED. GENERATING DIP FOR LH ENGINE STRUT DIAGONAL BRACE ON WING FITTING REPEAT INSPECTIONS OF REPAIR PERFORMED ON ECRA 5720-03 (N19117) - [SDR CALA2026093020007](https://openairdocs.org/sdr/CALA2026093020007), Aug 30, 2026: Boeing 757224. DRAG FITTING. UNKNOWN. LH ENGINE STRUT DRAG FITTING TO WING SKIN HOLES. REPAIR PERFORMED ON ECRA 5720-03677. ACCOMPLISH INSPECTIONS IAW PART 2. (N19117) - [SDR IPXA2026081505605](https://openairdocs.org/sdr/IPXA2026081505605), Aug 15, 2026: Airbus A300F4622R. FAIRING. CRACKED. UPON FURTHER INSPECTION CRACK DEFERRED ON TASK T3F18E0097P77 HAS GROWN TO 5.5€? BEYOND SRM LIMITS ON NR 1 ENGINE LOWER (N157UP) - [SDR IPXA2026082962661](https://openairdocs.org/sdr/IPXA2026082962661), Jul 8, 2026: Airbus A300F4622R. PLATE. DAMAGED. NR 2 PYLON, LT SIDE, FROM FR 5 TO FR 7, METALLIC PLATE WITH TOOL DAMAGE, MULTIPLE RIVETS DAMAGE AND HOLES WITH EVIDENCE (N144UP) - [SDR IPXA2026071772387](https://openairdocs.org/sdr/IPXA2026071772387), Jun 21, 2026: Boeing 7474R7F. DUCT. CRACKED. CRACKED DUCT , NR 1 ENG RT CORE COWL PRECOOLER EXHAUST DUCT. IAW AMM 71-11-06-004-001-J00, REV 117, AND AMM 71-11-06-404 (N583UP) - [SDR IPXA2026052439830](https://openairdocs.org/sdr/IPXA2026052439830), May 12, 2026: Boeing 767381. BUSHING. WORN. WORN - BUSHING, NR 2 ENG R/H CORE COWL R/H SIDE PRESSURE RELIFE DOOR UPPER AND LOWER SIDE, TOTAL: 2EA. .INSTALL NEW BUSH (N394UP) - [SDR FDEA202605090577](https://openairdocs.org/sdr/FDEA202605090577), May 9, 2026: Doug MD11F. BEARING. WORN. AFT SPHERICAL BEARING WORN. COMPLIED WITH EA 1-5450-T0386066 P2 (N621FE) - [SDR FDEA202605050546](https://openairdocs.org/sdr/FDEA202605050546), May 5, 2026: Doug MD11F. NACELLE. NOT REPORTED. NACELLES/PYLON - WING PYLON/STRUT - NO. 1 PYLON, INSPECTION AND REPAIR OF DAMAGE COMPLY WITH EA 1-5450-T0386263 REV NR P (N521FE) - [SDR IXXA20260417003](https://openairdocs.org/sdr/IXXA20260417003), Apr 17, 2026: Boeing 767223. ANGLE. CRACKED. CRACK NOTED AY PYLON #1 HYDRAULLIC BAY INTERNAL AREA, I/B SIDE FWD UPPER CORNER, CLOSE TO BOOT-STRAP ENGINE REMOVAL TOOL (N255CM) - [SDR UIEA2026031600090](https://openairdocs.org/sdr/UIEA2026031600090), Mar 15, 2026: Boeing 7474H6F. NOT REPORTED. NOT REPORTED. DEVIATION FOUND DURING PERFORMING SB-747-54A2245 ON BOTH SIDES ON NR 1 & 4 PYLON. PERFORM EI T2026A54M-360 REV 0. 2) ACC (N431GT) - [SDR UIEA2025121301343](https://openairdocs.org/sdr/UIEA2025121301343), Dec 13, 2025: Boeing 747409. STRUCTURE. NO DISCREPANCY. NR 1 ENG STRUCK GSE ON TOW IN. MX IN WORK WHILE IN AOGD FOR NR 1 ENG COWL DAMAGE. CONDITIONAL INSPECTIONS C/W PER AMM 05 (N780BA) - [SDR COEA2025110613778](https://openairdocs.org/sdr/COEA2025110613778), Oct 17, 2025: Textrn 408. MECHANISM. CRACKED. WO 271981 NR 5 MINOR REPAIR/DISCREPANCY: #1 AND #2 ENGINE SEPERATOR FWD DOOR LINK CRACKED. CORRECTIVE ACTION: REPLACED # (N778FX) - [SDR NACA202510229002](https://openairdocs.org/sdr/NACA202510229002), Sep 30, 2025: Boeing 76733A. CLAMP. MISINSTALLED. NR 2 ENGINE IDG WIRING HARNESS CLAMPS NOT PROPERLY INSTALLED PERFORMED PROPERLY INSTALLATION OF THE CLAMPS IN THE IDG WI (N567NC) - [SDR CALA2025100309582](https://openairdocs.org/sdr/CALA2025100309582), Sep 30, 2025: Boeing 737924ER. FAIRING. CRACKED. FOUND CRACK NO-2 PYLON LOWER FIXED FAIRING INTERNAL AFT SUPPORT RIB MKD DOT 022 REF AAR N/R 99957175 ESFR ENTERED. REMOV (N69804) - [SDR NACA2025092600001](https://openairdocs.org/sdr/NACA2025092600001), Sep 26, 2025: Boeing 76733A. CLAMP. UNSECURE. NR 2 ENGINE IDG WIRING HARNESS CLAMPS NOT PROPERLY INSTALLED. PERFORMED PROPERLY INSTALLATION OF THE CLAMPS IN THE IDG W (N567NC) - [SDR SWI2025F01593](https://openairdocs.org/sdr/SWI2025F01593), Aug 7, 2025: Cndair CL6002C10. FAN COWL. DAMAGED. RT UPPER FAN COWL HAS A DAMAGED HOLE (C-CHECK RO 11/22/2025)EVALUATED. MEASURES OF DAMAGE: LENGTH: 0.570", WIDTH: 0.398" (N759EV) - [SDR JR2R20250715257](https://openairdocs.org/sdr/JR2R20250715257), Jul 15, 2025: Emb ERJ170200LR. SKIRT. BENT. #2 ENG I/B FWD SKIRT SEAL BENT. (N85355) - [SDR IPXA2025072363772](https://openairdocs.org/sdr/IPXA2025072363772), Jul 4, 2025: Boeing 76734AF. VALVE. DAMAGED. CRACK - FLANGE, NO. 2 PYLON FAN AIR VALVE INLET. I.A.W. AMM 36-11-16-004-001-006, AND 36-11-16-404-015-006, REV.145, REP (N325UP) - [SDR HYIA20250522001](https://openairdocs.org/sdr/HYIA20250522001), May 20, 2025: Cessna 402C. FITTING. CRACKED. DURING SCHEDULED NDT INSPECTION AS NOTED IN SID 57-10-16, A CRACK WAS NOTED ON THE RIGHT HAND OUTBOARD NACELLE FITTING P (N290CA) - [SDR ERKR15050237717](https://openairdocs.org/sdr/ERKR15050237717), May 2, 2025: Boeing 777F6N. ACTUATOR. BROKEN. PDOS ACTUATOR ON NUMBER 2 ENG. I/B FAN COWL BROKEN - [SDR IPXA2025050533324](https://openairdocs.org/sdr/IPXA2025050533324), Apr 30, 2025: Airbus A300F4622R. SKIN. DEFORMED. #2 PYLON FWD FAIRING LH AND RH SIDE SUPPORT ANGLES (P/N A54612232200/201)DEFORMED FWD OF RIB J4. DOT# 110-99 JP-110 VERI (N125UP) - [SDR IPXA2025041273466](https://openairdocs.org/sdr/IPXA2025041273466), Apr 7, 2025: Airbus A300F4622R. BRACKET. CRACKED. AFT FAIRING PANEL 475AL O/B SIDE HAS A CRACKED BRACKET ON AFT PART OF PANEL.REMOVED THE CRACKED BRAKET AT PANEL 475AL O/ (N151UP) - [SDR UIEA2025031900234](https://openairdocs.org/sdr/UIEA2025031900234), Mar 15, 2025: Boeing 76731K. SKIN. GOUGED. ENG 1, LH SIDE, SKIN ON AFT TORQUE BOX WITH A GOUGE.(

ENG 1, LH SIDE, SKIN ON AFT TORQUE BOX DAMAGE WAS REPAIRED IAW T (N1373A) - [SDR JR2R20250211338](https://openairdocs.org/sdr/JR2R20250211338), Feb 11, 2025: Emb ERJ170200LR. PYLON. CHAFED. RH PYLON, 429ML, CHAFED IN MULTIPLE PLACES OUT OF LIMITS REQUIRING ENGINEERING APPROVAL. (N86324) - [SDR JR2R20250211339](https://openairdocs.org/sdr/JR2R20250211339), Feb 11, 2025: Emb ERJ170200LR. PYLON. CHAFED. LH PYLON, 419ML, CHAFED IN MULTIPLE PLACES OUT OF LIMITS REQUIRING ENGINEERING APPROVAL. (N86324) - [SDR JR2R20250211346](https://openairdocs.org/sdr/JR2R20250211346), Feb 11, 2025: Emb ERJ170200LL. PYLON. CHAFED. LH PYLON PANEL, 419NR, CHAFED IN MULTIPLE PLACES OUT OF LIMITS REQUIRING ENGINEERING APPROVAL. (N86324) - [SDR IPXA2025021446485](https://openairdocs.org/sdr/IPXA2025021446485), Feb 8, 2025: Airbus A300F4622R. FAIRING. DAMAGED. FAIRING # 485 AL HAS CRACK AT LH SIDE AFT SECTION . 89-29. INSTALLED MISSING BLIND RIVET ON AFT LOWER EXTERNAL SKIN AT R (N150UP) - [SDR IPXA2025011407643](https://openairdocs.org/sdr/IPXA2025011407643), Jan 9, 2025: Airbus A300F4622R. ANGLE. DAMAGED. STR-T3F18EOO3UPV4-LEFT LOWER AFT FAIRING HAS 9 EA CLIPS WITH DAMAGE ON OB SIDE REVIEWED.TREATED AND PRIMED (9EA) CLIPS I (N153UP) - [SDR R61A2025010400015](https://openairdocs.org/sdr/R61A2025010400015), Jan 5, 2025: Emb ERJ170100LR. FITTING. CRACKED. DURING HEAVY CHECK L/H PYLON INBD AFT LUG FITTING CRACKED. I/B AFT LUG REPLACED AS PER REPUBLIC AIRWAYS RO-030956-2024 (N747YX) - [SDR SWAA2024121978631](https://openairdocs.org/sdr/SWAA2024121978631), Dec 18, 2024: Boeing 7378H4. WEB. CRACKED. #2 ENGINE AFT STRUT FAIRING AFT WEDGE FWD WEB HAS CRACK PROTRUDING FROM LAP AND EXTENDING INBOARD BEYOND THE RADIUS. CRA (N8550Q) - [SDR IPXA2024121372254](https://openairdocs.org/sdr/IPXA2024121372254), Dec 12, 2024: Boeing 76734AF. INLET. CRACKED. R/H ENGINE INLET, INNER LIP, AT APPROXIMATE 12 O€™CLOCK POSITION, HAS 6 INCH CRACK SPANNING SEVERAL FASTENERS. REMOVED (N329UP) - [SDR DALA2024120311419](https://openairdocs.org/sdr/DALA2024120311419), Dec 3, 2024: Airbus A330323. FASTENER. ELONGATED. SHIP 3306 LH ENG LAPF IB FASTENER HOLE ELONGATED. CORRECTIVE ACTION: REMOVED OLD DOUBLER AND REAMED THE WORN HOLE, APPLI (N806NW) - [SDR HALA20241108317](https://openairdocs.org/sdr/HALA20241108317), Nov 7, 2024: Airbus A321271N. RAMP. DAMAGED. ETOPS - FIRELOOP RAMP ASSY-PYLON DAMAGED #2 ENGINE. REMOVED AND REPLACED RAMP ASSY COMPLETE WITH DETECTORS #2 ENG PER AM (N202HA) - [SDR CALA2024101800854](https://openairdocs.org/sdr/CALA2024101800854), Oct 16, 2024: Boeing 7879. STRUCTURE. DAMAGED. L ENG EVIDENCE OF BIRDSTRIKE ON ARRIVALREFERENCE AMM 05-51-18-00A-280A ACCOMPLISHED INSPECTION AROUND BIRD STRIKE AREA O (N25982) - [SDR SWAA2024100737737](https://openairdocs.org/sdr/SWAA2024100737737), Sep 14, 2024: Boeing 7378H4. WEB. CRACKED. RIGHT WING TRANSVERSE WEB ABOVE THE #2 PYLON AFT TIP IS CRACKED AT O/B UPPER END<[01] REMOVED; REPLACED; AND INSTALLED A (N8651A) - [SDR DALA2024091609073](https://openairdocs.org/sdr/DALA2024091609073), Sep 11, 2024: Airbus A319114. SCREW. MISSING. SHIP 3170 SCREW MISSING ON #2 ENGINE PYLON. CORRECTIVE ACTION: INSTALLED MISSING PYLON SCREW ON #2 ENG REF A320 AIPC 54- (N370NB) - [SDR SWAA2024091636197](https://openairdocs.org/sdr/SWAA2024091636197), Sep 10, 2024: Boeing 7377BD. BRACKET. SEPARATED. L/H ENGINE LOW PRESSURE TURBINE CASE COOLING TUBE SUPPORT ANGLE BRACKET; AT 4 OCLOCK POSITION; FORWARD FLANGE IS SEPARAT (N7745A) - [SDR SWIA2024091200819](https://openairdocs.org/sdr/SWIA2024091200819), Aug 19, 2024: Cndair CL6002B19. STRUCTURE. BENT. LH LEADING EDGE 530JL HAS SLIGHT BEND NEAR TRAILING EDGE INBOARD SIDE. APPROX 1.25" FROM TRAILING EDGE, AND 5.75" LONG S (N453SW) - [SDR VNAA202408070029](https://openairdocs.org/sdr/VNAA202408070029), Aug 7, 2024: Cndair CL6002C10. TRANSCOWL. CRACKED. UPON REMOVAL OF THE RH UPPER TRANSCOWL LATCH COAMING, FOUND THE UNDERLYING STRUCTURE TO BE CRACKED. REPAIRED R/H UPPER T (N719PS) - [SDR FXTA20240802001](https://openairdocs.org/sdr/FXTA20240802001), Aug 1, 2024: Textrn 408. ROD END. BROKEN. RH INERTIAL SEPARATOR INOPERATIVE. AFTER LANDING MAINTENANCE FOUND ROD END BROKEN THAT CONNECTS THE ELECTRIC ACTUATOR TO (N408BA) - [SDR JR2R20240727523](https://openairdocs.org/sdr/JR2R20240727523), Jul 27, 2024: Emb ERJ170200LR. GROUND STUD. CORRODED. LH WING IDG GROUNDING BRACKET CORRODE O/B AND AFT OF #1 PYLON. REPAIRED (N84307) - [SDR JR2R202407276316](https://openairdocs.org/sdr/JR2R202407276316), Jul 27, 2024: Emb ERJ170200LR. GROUND STUD. CORRODED. #2 ENGINE IDG GROUNDING BRACKET LOCATED IN THE TRAILING EDGE CAVITY O/B OF THE #2 PYLON CORRODED. REPAIRED (N84307) - [SDR IPXA2024072392472](https://openairdocs.org/sdr/IPXA2024072392472), Jul 19, 2024: Doug MD11F. STRUCTURE. DAMAGED. *SUPPLEMENTAL SDR* #1 ENGINE PYLON DAMAGED. REMOVED AND REPLACED #1 ENG WING PYLON AFT LOWER FAIRING PER AMM 54-81-01 AN (N264UP) - [SDR YENA2024062100891](https://openairdocs.org/sdr/YENA2024062100891), Jun 17, 2024: Airbus BD5001A11. DOOR. NO TEST. FLT#1530, RSW-JFK. ' R ENG PCE DOOR OPEN ON DESCENT DURING ICE TEST; ACCOMPLISHED T/R PRES RELIEF DOOR OPEN INSP PER AMP (N3132J) - [SDR CALA2024060701712](https://openairdocs.org/sdr/CALA2024060701712), Jun 5, 2024: Boeing 757224. STIFFENER. BUCKLED. REF AMES NON ROUTINE 171415-0400-0044. GENERATING ITEM:ZONE 430 OPEN.FEED BACK CABLE COVER PLATE IS BENT AND CRACKED TAG (N17104) - [SDR CALA2024060401690](https://openairdocs.org/sdr/CALA2024060401690), Jun 3, 2024: Boeing 767322. DRAIN. BLOCKED. NO. 1 ENGINE CENTER DRAIN AND RACEWAY DRAIN LINES INSPECTION {B767-71-3-0006} - HEAVY DEPOSITS FOUND IN INBOARD SIDE OF (N661UA) - [SDR MK1Y20240602003](https://openairdocs.org/sdr/MK1Y20240602003), Jun 2, 2024: Boeing 767330. STRUT. NOT REPORTED. REPAIR - STRUT #2 AFT FIXED FAIRING, INBD SKIN PANEL. (N447CM) - [SDR COEA2024080730738](https://openairdocs.org/sdr/COEA2024080730738), May 28, 2024: Textrn 408. MOUNT. CRACKED. WO 258209 NR 2 DISCREPANCY: R/H COWL, NACELLE, INERTIAL SEPARATOR MOUNTING STRUCTURE HAS CRACKS. CORRECTIVE ACTION: REPA (N738FX) - [SDR UIEA2024052500446](https://openairdocs.org/sdr/UIEA2024052500446), May 27, 2024: Boeing 74747UF. PANEL. DAMAGED. NO.4 PYLON 482EL SCREW HOLE FOUND ELONGATED.(

#4 PYLON PANEL 482EL FABRICATED IAW RI NO : RI-54-51-16889 REV A. HFEC I (N418MC) All 1,907: https://openairdocs.org/jasc/5400/reports.md ## Other codes in chapter 54 - [JASC 5410](https://openairdocs.org/jasc/5410): Nacelle/Pylon, Main Frame (4,100 reports) - [JASC 5411](https://openairdocs.org/jasc/5411): Nacelle/Pylon, Frame/Spar/Rib (1,453 reports) - [JASC 5412](https://openairdocs.org/jasc/5412): Nacelle/Pylon, Bulkhead/Firewall (1,086 reports) - [JASC 5413](https://openairdocs.org/jasc/5413): Nacelle/Pylon, Longeron/Stringer (220 reports) - [JASC 5414](https://openairdocs.org/jasc/5414): Nacelle/Pylon, Plate/Skin (4,353 reports) - [JASC 5415](https://openairdocs.org/jasc/5415): Nacelle/Pylon, Attach Fittings (1,305 reports) - [JASC 5420](https://openairdocs.org/jasc/5420): Nacelle/Pylon Miscellaneous Structure (3,946 reports) - [JASC 5497](https://openairdocs.org/jasc/5497): Nacelle/Pylon System Wiring (53 reports) --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.