N14063

Part: BATTERY PACK — INOPERATIVE (CABIN) · airframe 100,984 hrs · 21,797 cycles

THE EMERGENCY LIGHT TEST FUNCTION WOULD NOT GIVE A VALID TEST. THE L-2 DOOR EMERGENCY LIGHT BATTERY PACK WAS REMOVED AND REPLACED IAW MM 33-51-01. OPERATIONAL CHECKS WERE GOOD.

Part: SPAR — CRACKED (HORIZ STAB) · airframe 98,443 hrs · 21,263 cycles

INSPECTION FOUND A 1.3 INCH CRACK IN LT HORIZONTAL STABILIZER REAR SPAR CAP AFT BARREL NUT BORE. THE LT HORIZONTAL STABILIZER UPPER AFT SPAR CAP SECTION WAS REPLACED IAW ECRA 5511-01015.

Part: FLOORBEAM — CORRODED (FUSELAGE) · airframe 98,443 hrs · 21,263 cycles

INSPECTION FOUND FLOORBOARD SUPPORT BEAM CORRODED AT STA 420, X=28L. A SPLICE REPAIR WAS INSTALLED IAW SRM 53-70-00, FIGURE 13.

Part: CHANNEL — DAMAGED (BS 1801-1841)

INSPECTION FOUND DAMAGED CHANNEL SECTION IN CENTER CARGO BAY AT STA 1801-1841. THE CHANNEL WAS REPLACED WITH A NEW CHANNEL IAW MM 25-52-01.

Part: BRACKET — CRACKED (TAIL CONE)

INSPECTION FOUND TAIL CONE CENTER RT, UPPER RT, AND UPPER LT SPIGOT MOUNTING BRACKETS CRACKED. EACH BRACKET HAD A 3 INCH CRACK. THE BRACKETS WERE REPAIRED IAW SRM 53-30-00, FIGURE 3.

Part: SILL — CORRODED (CARGO DOORWAY)

INSPECTION FOUND CENTER CARGO BAY DOOR SILL LOWER AFT FRAME AND LOWER FORWARD FRAME CORRODED. THE LOWER AFT AND LOWER FORWARD FRAMES WERE REPAIRED IAW SRM 53-50-00, PAGES 119-130.

Part: BEAM — CORRODED (CARGO COMPT)

INSPECTION FOUND SUPPORT BEAM CORRODED AT CENTER CARGO BAY CENTER ROLLER CHANNEL ADJOINING BULK CARGO AREA. THE SUPPORT BEAM WAS REMOVED AND REPLACED IAW SRM 53-42-00.

Part: BOLT — SHEARED (LT MLG)

INSPECTION FOUND LT MLG BAY TRAPEZOIDAL FRAME UPPER FLANGE BOLT SHEARED. THE BOLT, NUT AND WASHERS WERE REPLACED IAW MM 20-20-01.

Part: SILL — CORRODED (CARGO DOOR)

INSPECTION FOUND THE FORWARD CARGO BAY FORWARD LOWER DOOR SILL CORRODED IN FORWARD CORNER. THE DOOR SILL WAS REPAIRED IAW SRM 53-50-00, FIGURE 9.

Part: RIB — CRACKED (WS 795)

INSPECTION FOUND A 1.5 INCH CRACK RT WING LEADING EDGE DOUBLER AND SUPPORT RIB AT STA XORS 795. THE LEADING EDGE DOUBLER AND SUPPORT RIB WERE REPAIRED IAW SRM 57-10-00, PAGE 163 AND SRM 57-31-01.

Part: ANGLE — CRACKED (VERT STAB)

INSPECTION FOUND A 3 INCH CRACK IN LT AND RT DRAG ANGLES BELOW NR 2 ENGINE AT THIRD BANJO FITTING. THE CRACKS WERE STOP DRILLED AND REPAIR ANGLES WERE INSTALLED IAW SRM 55-20-00, FIGURE 3.

Part: DOOR — CRACKED (LT MLG)

INSPECTION FOUND A 4 INCH CRACK IN Z SECTION AT FORWARD CORNER OF LT MLG DOOR. THE DOOR WAS REPAIRED IAW SRM 52-10-00, FIGURE 15.

Part: WIRE — SHORTED (ROW 29 & 36)

INSPECTION FOUND THE EMERGENCY AISLE PATH LIGHTING AT SEAT ROWS 29/36KL INOPERATIVE. A POWER WIRE WAS FOUND DAMAGED AND SHORTED UNDER SEAT 36L CAUSING POWER SUPPLY FUSES TO BLOW. THE WIRE WAS REPAIRED AND THE FUSES WERE REPLACED.

Part: WIRE — BROKEN (CABIN)

ROW 33 AND 34 L AND K EMERGENCY LIGHTS INOP. RESECURED BROKEN WIRE FOR EMERGENCY LIGHTS.

Part: DUCT — RUPTURED (NR 3 ENGINE)

THE NR 3 ENGINE FIRE WARNING LIGHT ILLUMINATED WHILE EN ROUTE. BOTH FIRE BOTTLES WERE DISCHARGED, BUT THE LIGHT REMAINED ILLUMINATED. THE AIRCRAFT WAS DIVERTED TO SNN WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE NR 3 ENGINE 8TH STAGE PNEUMATIC DUCT RUPTURED. THE DUCT WAS REMOVED AND REPLACED.

Part: SUPPORT — CORRODED (BS 455)

INSPECTION FOUND CORROSION ON FLOOR OMEGA SUPPORT AT STA 455, RBL 45. THE FLOOR SUPPORT WAS REMOVED. A NEW FLOOR SUPPORT WAS FABRICATED AND INSTALLED IAW SRM 53-70-00, 51-20-00, AND 51-31-01.

Part: AIR BOTTLE — LOW PRESSURE (L2 DOOR)

INSPECTION FOUND L-2 DOOR AIR BOTTLE PRESSURE LOW. THE AIR BOTTLE WAS FILLED IAW MM 52-12-06.

Part: AIR BOTTLE — LOW PRESSURE (L3 DOOR)

INSPECTION FOUND L-3 DOOR AIR BOTTLE PRESSURE LOW. THE AIR BOTTLE WAS FILLED IAW MM 52-12-06.

Part: JAMB — CORRODED (BS 1964)

INSPECTION FOUND CORROSION ON ENTRY LOWER AFT CARGO JAMB BOX AT STA 1964 BETWEEN STRINGER 40-46. THE CORRODED AREAS WERE REMOVED. A STRAP, DOUBLERS, PLUG, ANGLE, AND FILLER WERE FABRICATED AND INSTALLED IAW SRM 53-50-00, FIGURE 14.

Part: AIR BOTTLE — LOW PRESSURE (R1 DOOR)

INSPECTION FOUND R-1 DOOR AIR BOTTLE PRESSURE LOW. THE AIR BOTTLE WAS FILLED IAW MM 52-11-06.

Part: CHARGER — INOPERATIVE (CABIN)

INSPECTION FOUND ZONE-A EMERGENCY LIGHT BATTERY PACK INOPERATIVE. THE EMERGENCY LIGHT CHARGER WAS REPLACED AND OPERATION CHECKED GOOD IAW MM 33-50-00.

Part: RIBS — CRACKED (NR 1 LE SLAT)

INSPECTION FOUND A 1 INCH CRACK IN THREE RIBS OF NR 1 LT SLAT. THE CRACKED RIBS WERE REMOVED. NEW RIBS WERE FABRICATED AND INSTALLED IAW SRM 57-55-01 FIGURE 2 51-20-00 AND 51-31-01.

Part: BRACKET — CORRODED (NR 2 PYLON)

INSPECTION FOUND NR 2 PYLON UPPER PYLON TRAILING EDGE ATTACH BRACKET CORRODED. A REPAIR WAS FABRICATED AND INSTALLED IAW SRM 54-32-02, 51-38-01, FIGURE 13, 51-21-01, 51-31-01.

Part: FLOOR POST — BROKEN (BS 1100)

INSPECTION FOUND CABIN FLOOR POST BROKEN IN FORWARD CARGO AREA AT STA 1100. THE AREA WAS TRIMMED AND BLENDED OUT. A REPAIR CHANNEL, ANGLE, AND FILLER WERE FABRICATED AND INSTALLED IAW SRM 51-20-00 AND ENGINEERING ORDER MF MAN D10-53-86801.

Part: MOUNT — CRACKED (TAIL CONE)

INSPECTION FOUND TAILCONE UPPER SECTION RT WORK PLATFORM FORWARD MOUNT RIVETS LOOSE AND CRACKED. THE MOUNT WAS REMOVED AND A NEW MOUNT WAS FABRICATED AND INSTALLED IAW SRM 51-20-00, 51-31-01, AND 53-52-01, FIGURE 2.

Part: FLOOR WEB — CRACKED (BS 879)

INSPECTION FOUND A 5 INCH CRACK ON FORWARD CARGO LOWER FLANGE OF FLOOR WEB AT STA 879 LBL 50. THE FLANGE WAS TRIMMED AND BLENDED OUT AND THE AREA WAS REWORKED. TWO ANGLES WERE INSTALLED IAW SRM 53-00-01, FIGURE 3, 51-20-00, AND 51-31-01.

Part: T-PROFILE — CRACKED (RT HORIZ STAB)

INSPECTION FOUND SEVERAL 1 CRACKS IN INBOARD AND OUTBOARD ATTACH FLANGES OF RT HORIZONTAL STABILIZER NR 3 LEADING EDGE T-PROFILE. THE STRAP AND T-PROFILE WERE REMOVED. A NEW T-PROFILE WAS FABRICATED AND INSTALLED IAW SRM 51-20-00 AND 51-31-01.

Part: JAMB — CORRODED (CARGO DOOR)

INSPECTION FOUND LOWER AFT CARGO DOOR JAMB CORRODED BETWEEN STA 1921 AND 1942. THE CORRODED AREA WAS REMOVED. REPAIR PARTS WERE FABRICATED AND INSTALLED IAW SRM 51-21-01, 53-50-00, FIGURE 15A, AND 51-31-01.

Part: FLOORBEAM — BROKEN (BS 1293)

INSPECTION FOUND INTERIOR UPPER LOBE CABIN FLOORBEAM BROKEN AT STA 1293, RBL 103. THE FLOORBEAM WAS REPAIRED IAW ECRA 5320-01511 AND ENGINEERING ORDER MF MAN D10-53-896798.

Part: STRINGER — CORRODED (BS 1581-1601)

INSPECTION FOUND STRINGER 52 CORRODED IN CENTER CARGO AREA AT STA 1581-1601. THE STRINGER WAS REMOVED. A NEW PART WAS INSTALLED IAW SRM 51-21-01.

Part: LONGERON — CORRODED (BS 1521-1541)

INSPECTION FOUND LONGERON 48L CORRODED IN CENTER CARGO AREA AT STA 1521-1541. THE CORRODED AREA WAS CLEANED AND BLENDED OUT. A NEW ANGLE WAS FABRICATED, THE AREA WAS REWORKED, AND REPAIR WAS INSTALLED IAW SRM 51-21-01 AND 51-31-01.

Part: CHORD — CORRODED (BS 1781)

INSPECTION FOUND LOWER CHORD IN CENTER CARGO AREA CORRODED AT STA 1781, STRINGER 51. THE CORRODED AREA WAS REMOVED AND THE AREA WAS REWORKED. A NEW PART WAS INSTALLED USING RIVETS AND REINFORCED WITH SHEAR CLIP IAW SRM 53-30-00, FIGURE 9, 51-20-00, AND 51-31-01.

Part: FLANGE — CORRODED (BS 1821)

INSPECTION FOUND LOWER FLANGE IN CENTER CARGO AREA CORRODED AT STA 1821, STRINGER 51. THE CORRODED AREA WAS TRIMMED AND BLENDED OUT, REWORKED, AND REINFORCED WITH SHEAR CLIP IAW SRM 53-30-00, FIGURE 9. NEW PARTS WERE FABRICATED AND INSTALLED USING RIVETS IAW SRM 51-21-01 AND 51-31-01.

Part: CHORD — CORRODED (BS 1761)

INSPECTION FOUND LOWER CHORD IN CENTER CARGO AREA CORRODED AT STA 1761, STRINGER 51 TO 47L. THE CORRODED AREA WAS REMOVED. A NEW PART AND SHEAR CLIP WERE FABRICATED IAW SRM 51-20-00. THE AREA WAS REWORKED, REINFORCED, AND RIVETED IAW 53-30-00, FIGURE 9 AND 51-31-01.

Part: FLANGE — CORRODED (BS 1761)

INSPECTION FOUND LOWER FLANGE IN CENTER CARGO AREA CORRODED AT STA 1761, STRINGER 48. THE CORRODED AREA WAS TRIMMED AND BLENDED OUT. A NEW CHORD WAS FABRICATED IAW SRM 53-15-01, FIGURE 12. THE AREA WAS REWORKED AND REINFORCED WITH A SPLICE AND RIVETED IN PLACE IAW SRM 53-30-00, FIGURE 5, 51-21-01, AND 51-31-01.

Part: FLANGE — CORRODED (BS 1741)

INSPECTION FOUND LOWER FLANGE IN CENTER CARGO AREA CORRODED AT STA 1741, STRINGER 48. THE CORRODED AREA WAS TRIMMED AND BLENDED OUT. A NEW CHORD WAS FABRICATED IAW SRM 53-15-01, FIGURE. THE AREA WAS REWORKED, REINFORCED WITH SPLICE, AND INSTALLED USING RIVETS IAW SRM 53-30-00, FIGURE 5, 51-21-01, AND 51-31-01.

Part: FLANGE — CORRODED (BS 1781)

INSPECTION FOUND LOWER FLANGE IN CENTER CARGO AREA CORRODED AT STA 1781, STRINGER 47-48R. THE CORRODED AREA WAS TRIMMED AND BLENDED OUT. A NEW CHORD WAS FABRICATED, THE AREA REWORKED AND REINFORCED WITH SPLICE AND RIVETED IAW SRM 53-15-01, FIGURE 12, 53-30-00, FIGURE 5, 53-21-01, AND 51-31-01.

Part: FLOORBEAM — BROKEN (BS 1275)

INSPECTION FOUND INTERIOR UPPER LOBE CABIN FLOORBEAM BROKEN AT STA 1275, RBL 103. THE FLOORBEAM WAS REPAIRED IAW ECRA 5320-01511 AND ENGINEERING ORDER MF MAN D10-53-896798.

Part: SUPPORT — CORRODED (BS 492)

INSPECTION FOUND FLOOR SUPPORT CORRODED AT STA 492, RBL 30. THE FLOOR SUPPORT WAS REMOVED AND A NEW FLOOR SUPPORT WAS FABRICATED AND INSTALLED IAW SRM 53-12-15, FIGURE 1 AND 26, 51-20-00, AND 51-31-01.

Part: ANGLE — CORRODED (BS 2007)

INTERIOR UPPER LOBE CABIN UNDER FLOOR LAV/GALLEY CORROSION ON FLOOR SUPPORT ANGLE AT STA 2007 BETWEEN LBL 56 AND 63. THE CORROSION WAS TRIMMED AND BLENDED OUT. A SPLICE ANGLE AND U-SPLICE CHANNEL WERE FABRICATED AND INSTALLED IAW SRM 51-20-00, 53-40-00, FIGURE 16, AND 51-31-01.

Part: SUPPORT — CORRODED (BS 1841-1884)

INTERIOR UPPER LOBE CABIN UNDER FLOOR LAV/GALLEY CORROSION ON FLOOR SUPPORT BETWEEN STA 1841 AND 1884 AT RBL 34. THE FLOOR SUPPORT WAS REMOVED. A NEW FLOOR SUPPORT WAS FABRICATED AND INSTALLED IAW SRM 53-12-15, FIGURE 1 AND 26, 51-20-00, AND 51-31-01.

Part: PANEL — CRACKED (FUSELAGE)

INSPECTION FOUND A 2 INCH CRACK IN LT NR 4 BANJO FITTING INNER ACCESS PANEL. THE PANEL WAS REMOVED AND A NEW PANEL WAS FABRICATED AND INSTALLED IAW SRM 51-20-00 AND 51-31-01.

Part: SUPPORT — CRACKED (BS 1942)

INTERIOR UPPER LOBE CABIN UNDER FLOOR LAV/GALLEY 1 CRACK ON FLOOR SUPPORT ABOVE STA 1942 AT RBL 3. THE FLOOR SUPPORT WAS REMOVED. A NEW FLOOR SUPPORT WAS FABRICATED AND INSTALLED IAW SRM 51-21-00, 51-31-01, AND 53-16-01.

Part: VENT BOX — CORRODED (BS 1480)

INSPECTION FOUND CORROSION ON VENT BOX AT STA 1480 AT ATTACHMENT TO LONGERON 27R. CORRODED TRUSS WAS REMOVED. A NEW PART WAS FABRICATED AND INSTALLED IAW SRM 51-20-00, 51-31-01, AND 53-14-01, FIGURE 5, ITEM 42.

Part: SUPPORT — CORRODED (BS 824-879)

INTERIOR UPPER LOBE CABIN UNDER FLOOR LAV/GALLEY CORROSION ON FLOOR SUPPORT BETWEEN STA 824 AND 879, RBL 73. THE FLOOR SUPPORT WAS REMOVED. A NEW FLOOR SUPPORT WAS FABRICATED AND INSTALLED IAW SRM 53-12-15, FIGURE 1 AND 26, 51-20-00, AND 51-31-01.

Part: SUPPORT — CORRODED (BS 1986)

INTERIOR UPPER LOBE CABIN UNDER FLOOR LAV/GALLEY CORROSION AND A 1 CRACK ON FLOOR SUPPORT ABOVE FLOORBEAM AT STA 1986 AT RBL 4. THE FLOOR SUPPORT WAS REMOVED. A NEW FLOOR SUPPORT WAS FABRICATED AND INSTALLED IAW SRM 51-20-00, 51-31-01, AND 53-16-01.

Part: FRAME — CRACKED (TAIL CONE)

INSPECTION FOUND A 1 INCH CRACK IN TAIL CONE UPPER SECTION LT SIDE RIB NR 8. THE RIB AND SPLICE WERE REMOVED. A NEW FRAME AND SPLICE WERE FABRICATED AND INSTALLED IAW SRM 53-30-00, FIGURE 1, 51-20-00, AND 51-31-01.

Part: SUPPORT — CORRODED (BS 1964)

INTERIOR UPPER LOBE CABIN FLOOR LAV/GALLEY CORROSION ON FLOOR SUPPORT AT STA 1964, RBL 20. THE FLOOR SUPPORT WAS REMOVED. A NEW FLOOR SUPPORT WAS FABRICATED AND INSTALLED IAW SRM 53-12-15, FIGURE 1 AND 26 AND 51-31-01.

Part: SUPPORT — CORRODED (BS 1884-1997)

INTERIOR UPPER LOBE CABIN UNDER FLOOR LAV/GALLEY CORROSION ON FLOOR SUPPORT BETWEEN STA 1884 AND 1997, LBL 25. THE FLOOR SUPPORT WAS REMOVED. A NEW FLOOR SUPPORT WAS FABRICATED AND INSTALLED IAW SRM 53-12-15, FIGURE 1 AND 26, 51-20-00, AND 51-31-01.

Part: FLOOR TRACK — CORRODED (BS 840)

INTERIOR UPPER LOBE CABIN UNDER FLOOR LAV/GALLEY CORROSION ON FLOOR TRACK AT STA 840, RBL 27. THE FLOOR TRACK WAS REMOVED, A NEW TRACK WAS INSTALLED IAW SRM 53-70-00, 51-20-00, AND 51-31-01.

Part: ANGLE — CRACKED (BS 1381)

INSPECTION FOUND A 1 INCH CRACK ON FAIRING SUPPORT ANGLE AT STA 1381, STRINGER 32R. THE SUPPORT ANGLE WAS REMOVED. A NEW ANGLE WAS FABRICATED AND INSTALLED IAW SRM 53-53-01, FIGURE 3, 51-20-00, AND 51-31-01.

Part: ANGLE — CRACKED (BS 1421)

INSPECTION FOUND A 1 INCH CRACK ON FAIRING SUPPORT ANGLE AT STA 1421, STRINGER 32R. THE SUPPORT ANGLE WAS REMOVED. A NEW ANGLE WAS FABRICATED AND INSTALLED IAW SRM 51-20-00, 51-31-01, AND 53-53-01, FIGURE 3.

Part: SUPPORT — CORRODED (BS 1841-1884)

INTERIOR UPPER LOBE CABIN UNDER FLOOR LAV/GALLEY CORROSION ON FLOOR SUPPORT BETWEEN STA 1841 AND 1884, BL 0 TO LBL 8. THE FLOOR SUPPORT WAS REMOVED. A NEW FLOOR SUPPORT WAS FABRICATED AND INSTALLED IAW SRM 53-12-15, FIGURE 1 AND 26, 51-20-00, AND 51-31-01.

Part: SUPPORT — CORRODED (BS 455)

INSPECTION FOUND FLOOR SUPPORT CORRODED AT STA 455, LBL 60. THE FLOOR SUPPORT WAS REMOVED AND A NEW FLOOR SUPPORT WAS FABRICATED AND INSTALLED IAW SRM 53-12-15, FIGURE 1 AND 26, 51-31-01, AND 51-20-00.

Part: O-RING — LEAKING (NR 3 HYD SYS)

THE HYD SYS 3 ELEVATOR OFF LIGHT ILLUMINATED. THE NR 3 PRESSURE AND QUANTITY WERE NORMAL. APPROXIMATELY 2.5 HOURS LATER THE SYSTEM 3 PRESSURE LIGHTS CAME ON. BOTH PUMPS WERE TRIED, BUT THE PRESSURE STILL DROPPED WITH THE QUANTITY INDICATING 7 GALLONS. ALTERNATE GEAR EXTENSION WAS USED AND THE AIRCRAFT LANDED WITHOUT INCIDENT. THE NR 3 HYD SYSTEM WAS FOUND EMPTY. MAINTENANCE FOUND UNION LEAKING AT 2 TO 3 REV PUMP. THE O-RING AT THE UNION WAS REMOVED AND REPLACED. IN ADDITION, THE NR 3 HYD QUANTITY GUAGE WAS REMOVED AND REPLACED DUE TO FAULTY OPERATION. THE NR 3 HYD SYSTEM WAS SERVICED. LEAK AND OPERATIONAL CHECKS WERE GOOD.

Part: SKIN — TORN (RT ELEVATOR)

INSPECTION FOUND INBOARD AFT CORNER OF RT OUTBOARD ELEVATOR SKIN TORN WITH SKIN PULLING THROUGH FASTENERS. A CLASS-B REPAIR WAS INSTALLED IAW SRM 55-22-00, PAGE 4. A DIP WAS ISSUED TO REINSPECT THE AREA AT EACH B-CHECK AND INSTALL A-CLASS 1 REPAIR WITHIN 12,000 HOURS.

Part: BATTERY — INOPERATIVE (CABIN)

THE EMERGENCY LIGHTS WOULD NOT TEST IN ARMED POSITION. THE FORWARD BATTERY PACK AND CHARGER AND AFT BATTERY PACK WERE REMOVED AND REPLACED. A SYSTEM TEST WAS PERFORMED AND OPERATION OF THE EMERGENCY LIGHTS CHECKED NORMAL.

Part: FAN AIR VLV — INOPERATIVE (NR 2 PNEU SYS)

THE NR 2 PNEUMATIC SUPPLY TEMP HIGH LIGHT ILLUMINATED DURING CLIMBOUT OF FRA NR 1 PNEUMATIC SYSTEM WAS PLACARD INOPERATIVE. THE NR 2 PNEUMATIC SUPPLY WAS SHUT OFF AND THE LIGHT EXTINGUISHED. FUEL WAS DUMPED AND THE AIRCRAFT WAS RETURNED TO FRA WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE NR 2 FAN AIR VALVE AT FAULT. THE FAN AIR VALVE WAS REPLACED. AN ENGINE POWER ASSURANCE RUN WAS PERFORMED AND ALL TEMPERATURE INDICATIONS WERE NORMAL.

Part: DUCT — SEPARATED (NR 1 ENGINE)

THE 1 ENGINE FIRE WARNING LIGHT ILLUMINATED ON TAKEOFF ROLL AT APPROXIMATELY 120 KNOTS. THE ENGINE FAIL/FIRE CHECKLIST WAS ACCOMPLISHED. THE FIRE LIGHT WENT OUT APPROXIMATELY 10 SECONDS AFTER RETARDING THE NR 1 THROTTLE. THE NR 1 ENGINE B-LOOP LIGHT WAS STILL ILLUMINATED. THE SYSTEM TESTED VALID WHEN SWITCHED TO A. MAINTENANCE FOUND THE NR 1 ENGINE HIGH STAGE PNEUMATIC DUCT SEPARATED WITH RESULTING DAMAGE TO BOTH THRUST REVERSER COWLS. REMOVED AND REPLACED THE PNEUMATIC DUCT, THE LT AND RT FAN REVERSERS. A POWER ASSURANCE RUN WAS PERFORMED, OPERATION CHECKED GOOD.