# Service difficulty reports: N991Z, cancelled Aug 28, 2001

A list on [N991Z, cancelled Aug 28, 2001](https://openairdocs.org/deregistered/N991Z-2001-08-28.md).

Matched to this aircraft by N-number and event date, checked against the reported serial number, make and model. Newest first.

- [SDR TWAA9912305](https://openairdocs.org/sdr/TWAA9912305.md): Light · inop · Sep 10, 1999 · N991Z · Doug DC931 · Emergency Lighting
  > DURING LANDING NOTICED A SECTION OF COACH EGRESS LIGHTS INOP. REPLACED LIGHT STRIP AND BATTERY PACK. CC 7-23-99 STL.
- [SDR TWAA9805907](https://openairdocs.org/sdr/TWAA9805907.md): Spar · cracked · Feb 14, 1998 · N991Z · Doug DC931 · Wing Spar
  > MCI - DURING OP 15 MAINTENANCE CHECK, FOUND RT WING AFT FLAP INBD HINGE CASTING, LOWER INBD HOLE ON REAR SPAR, HAD A CRACK INDICATION ON FACE. INSTALLED REPAIR DOUBLER PER PRINT JO60271 PER WORK SHEET MC8-AD-36. ACFT TT: 70,732 HOURS. ACFT TC: 76,937. (X
- [SDR TWAA9801401](https://openairdocs.org/sdr/TWAA9801401.md): Valve · worn · Jan 24, 1998 · N991Z · Doug DC931 · Pressure Regulator/Outflow Valve
  > STL - FLT 107 - AFTER NORMAL TAKEOFF AND PRESSURIZATION NORMAL, AT APPROX 5000 MSL NOTICED OUTFLOW VALVE CLOSED AND PACK PRESSURE NORMAL BUT AIRCRAFT NOT PRESSURIZING. FLIGHT OPERATED AT 10,000 FT WITH PACKS OFF. REPLACED THE RIGHT AC FLOW CONTROL VALVE. AL
- [SDR TWAA9800801](https://openairdocs.org/sdr/TWAA9800801.md): Regulator · failed · Jan 16, 1998 · N991Z · Doug DC931 · Cabin Cooling System
  > STL - FLT 283 - DURING CLIMB, CABIN ALTITUDE CONTINUED TO CLIMB. REPLACED RT PACK REGULATOR MFG P/N 392454-3-1. (M)
- [SDR TWAA9710202](https://openairdocs.org/sdr/TWAA9710202.md): Power Supply · inoperative · Aug 26, 1997 · N991Z · Doug DC931 · Emergency Lighting
  > STL - FLT 608 - DURING CRUISE, THE EMERGENCY LIGHTS ILLUMINATED. REMOVED AND REPLACED THE POWER SUPPLY. OPERATIONAL CHECK NORMAL. MFG P/N 5822-2, MANUFACTURED BY LUMINESCENT SYSTEMS INC. (M)
- [SDR TWAA9799002](https://openairdocs.org/sdr/TWAA9799002.md): Battery Pack · discharged · Aug 23, 1997 · N991Z · Doug DC931 · Emergency Lighting
  > STL - FLT 565 - DURING CRUISE, THE EMERGENCY LIGHTS ILLUMINATED. REMOVED AND REPLACED THE BATTERY PACK, MFG P/N 5822-2 MANUFACTURED BY LUMINESCENT SYSTEMS INC. OPERATIONAL CHECK NORMAL. (M)
- [SDR TWAA9798002](https://openairdocs.org/sdr/TWAA9798002.md): Battery Pack · discharged · Aug 22, 1997 · N991Z · Doug DC931 · Emergency Lighting
  > STL - FLT 237 - DURING CRUISE, THE EMERGENCY ESCAPE PATH LIGHTING ILLUMINATED INTERMITTENTLY. REMOVED AND REPLACED THE BATTERY PACK, MFG P/N 5822-2, MANUFACTURED BY LUMINESCENT SYSTEMS INC. (M)
- [SDR TWAA9797001](https://openairdocs.org/sdr/TWAA9797001.md): Battery Pack · discharged · Aug 18, 1997 · N991Z · Doug DC931 · Emergency Lighting
  > STL - FLT 502 - DURING CRUISE, THE EMERGENCY LIGHTS ILLUMINATED. REMOVED AND REPLACED THE BATTERY PACK MFG PN 5822-2, MANUFACTURED BY LUMINESCENT SYSTEMS INC. OPERATIONAL CHECK NORMAL. (M)
- [SDR TWAA9783001](https://openairdocs.org/sdr/TWAA9783001.md): Power Supply · malfunctioned · Jul 23, 1997 · N991Z · Doug DC931 · Emergency Lighting
  > STL - FLT 291 - DURING CRUISE, EGRESS LIGHTS ILLUMINATED. REMOVED AND REPLACED POWER SUPPLY, MFG P/N 100865, MANUFACTURED BY BRUCE INDUSTRIES. OPS CHECK NORMAL. OP-15 - 2-17-97 - MCI. (X)
- [SDR TWAA9782001](https://openairdocs.org/sdr/TWAA9782001.md): Power Pack · inoperative · Jul 22, 1997 · N991Z · Doug DC931 · Emergency Lighting
  > STL - FLT 663 - DURING ROUTINE MAINTENANCE, EMERGENCY LIGHTS ILLUMINATED. REMOVED AND REPLACED POWER PACK, MFG P/N 5822-2, MANUFACTURED BY LUMINESCENT SYSTEMS, INC. OPS CHECK NORMAL. OP-15 - 2-17-97 - MCI. (X)
- [SDR TWAA9781005](https://openairdocs.org/sdr/TWAA9781005.md): Power Pack · illuminated · Jul 22, 1997 · N991Z · Doug DC931 · Emergency Lighting
  > STL - FLT 410 - DURING CRUISE, EMERGENCY LIGHTS ILLUMINATED. REMOVED AND REPLACED POWER PACK, MFG PN 5822-2, MANUFACTURED BY LUMINESCENT SYSTEMS, INC. OPS CHECK NORMAL. OP-15 - 2-17-97 - MCI. (X)
- [SDR TWAA9750001](https://openairdocs.org/sdr/TWAA9750001.md): Switch · failed · Apr 16, 1997 · N991Z · Doug DC931 · Landing Gear Position and Warning
  > STL - FLT 302 - DURING CLIMB, LEFT GEAR DOOR WARNING LIGHT STAYED ON. CYCLED GEAR, NO HELP. REMOVED AND REPLACED LEFT GEAR DOOR WARNING SWITCH, MFG P/N H14-6, MANUFACTURED BY EATON CORPORATION. OPERATIONAL CHECK NORMAL. (M)
- [SDR TWAA9710002](https://openairdocs.org/sdr/TWAA9710002.md): Battery Pack · discharged · Feb 17, 1997 · N991Z · Doug DC931 · Emergency Lighting
  > STL - FLT 295 - DURING CRUISE, THE ESCAPE PATH LIGHTING ILLUMINATED. REMOVED AND REPLACED THE BATTERY PACK, MFG 5822-2, MANUFACTURED BY LUMINESCENT SYSTEMS INC. (M)
- [SDR TWAA9809508](https://openairdocs.org/sdr/TWAA9809508.md): Skin · dented · Feb 14, 1997 · N991Z · Doug DC931 · Leading Edge Devices
  > MCI - DURING OP 15 MAINTENANCE CHECK, FOUND NR 1 L/E SLAT WITH DENTS IN THE L/E. REPAIRED DENTS PER SRM 57-03, PAGE 18A PAR 12B, ITEM A, REFERENCE SRM 51-70-2 PAGE 3 FIG 1. ACFT TT: 51,723 HOURS. ACFT TC: 52,362. (X)
- [SDR TWAA9809507](https://openairdocs.org/sdr/TWAA9809507.md): Frame · cracked · Feb 14, 1997 · N991Z · Doug DC931 · Fuselage Main, Frame
  > MCI - DURING OP 15 MAINTENANCE CHECK, FOUND FUSELAGE FRAME AT STA 1110 WITH APPROXIMATELY.25 INCH CRACK AT L13R AND L14R. REPAIRED PER SRM 53-03, FIG 4 PAGE 5. ACFT TT: 51,723 HOURS. ACFT TC: 52,362. (X)
- [SDR TWAA9809506](https://openairdocs.org/sdr/TWAA9809506.md): Skin · bulged · Feb 14, 1997 · N991Z · Doug DC931 · Fuselage Main, Plate/Skin
  > MCI - DURING OP 15 MAINTENANCE CHECK, FOUND AT FS 180 BETWEEN L21L TO L22L, AREA HAD A RAISED PLACE IN THE SKIN. REPAIRED PER SRM 51-50-00, AND INSTALLED DOUBLER PER SRM 53-04, FIG 38 SHT 23 PAGE 218. ACFT TT: 51,723 HOURS. ACFT TC: 52,362. (X)
- [SDR TWAA9809415](https://openairdocs.org/sdr/TWAA9809415.md): Longeron · chafed · Feb 14, 1997 · N991Z · Doug DC931 · Fuselage Main, Longeron/Stringer
  > MCI - DURING OP 15 MAINTENANCE CHECK, FOUND A HOLE WORN THROUGH THE UPPER FLANGE OF LONGERON 8L, STA 1066. REPAIRED PER SRM 53-02, FIG 5. (X)
- [SDR TWAA9809414](https://openairdocs.org/sdr/TWAA9809414.md): Floorbeam · corroded · Feb 14, 1997 · N991Z · Doug DC931 · Fuselage Main, Floor Beam
  > MCI - DURING OP 15 MAINTENANCE CHECK, FOUND CORROSION ON LOWER SIDE OF THE FLOORBEAM AT STA 200, LBL 43 INCHES TO RBL 43 INCHES. REMOVED CORROSION PER SRM 51-10-03, AND REPAIRED PER SRM 53-01, FIG 25 SHT 4, PAGE 9. (X)
- [SDR TWAA9805506](https://openairdocs.org/sdr/TWAA9805506.md): Hinge · cracked · Feb 14, 1997 · N991Z · Doug DC931 · Trailing Edge Flaps
  > MCI - DURING OP 15 MAINTENANCE CHECK, FOUND AFT FLAP INBOARD HINGE CASTING LOWER INBOARD HOLE ON REAR SPAR CRACKED ON FACE APPROX.75 INCH. INSTALLED REPAIR DOUBLER PER PRING J060271 PER WORK FORM MC8-AD-36. (M)
- [SDR TWAA9805801](https://openairdocs.org/sdr/TWAA9805801.md): Skin · cracked · Feb 7, 1997 · N991Z · Doug DC931 · Trailing Edge Flaps
  > MCI - DURING OP 15 MAINTENANCE CHECK, FOUND TE OF RT TE FLAP WITH SMALL CRACK APPROX.25 NCH AND PIECE OF METAL MISSING APPROX 8 INCH FROM INBOARD END. INSTALLED METAL TO METAL HOT BOND REPAIR PER SRM 57-50-14 AND 51-70-2, ITEM B PAGE 69. (M)
- [SDR 96ZZZM1481](https://openairdocs.org/sdr/96ZZZM1481.md): Fuel Control · malfunctioned · Oct 12, 1996 · N991Z · Doug DC931 · Fuel Control/Turbine Engines
  > PIT - DURING CLIMB, NR 1 ENGINE, S/N 2106, WOULD NOT RESPOND TO THRUST LEVER MOVEMENT. SHUT DOWN ENGINE. REPLACED ENGINE DRIVEN FUEL PUMP, MFG P/N 378201-7 AND FUEL CONTROL, MFG P/N 743602-5. ENGINE OPERATION CHECKED NORMAL.
- [SDR 96ZZZM1480](https://openairdocs.org/sdr/96ZZZM1480.md): Fuel Pump · malfunctioned · Oct 12, 1996 · N991Z · Doug DC931 · Engine Fuel Pump
  > PIT - DURING CLIMB, NR 1 ENGINE, S/N 2106, WOULD NOT RESPOND TO THRUST LEVER MOVEMENT. SHUT DOWN ENGINE. REPLACED ENGINE DRIVEN FUEL PUMP, MFG P/N 378201-7 AND FUEL CONTROL, MFG P/N 743602-5. ENGINE OPERATION CHECKED NORMAL.
- [SDR 96ZZZM1447](https://openairdocs.org/sdr/96ZZZM1447.md): Power Supply · inoperative · Oct 8, 1996 · N991Z · Doug DC931 · Emergency Lighting
  > STL - DURING DESCENT, EGRESS LIGHT IN FIRST CLASS ILLUMINATED. FOUND FAULTY BATTERY POWER SUPPLY, MFG P/N 5822-2. REPLACED BATTERY POWER SUPPLY AND EGRESS LIGHTING SYSTEM OPERATION CHECKED NORMAL. (M)
- [SDR 96ZZZX1204](https://openairdocs.org/sdr/96ZZZX1204.md): Connector · dirty · Feb 17, 1996 · N991Z · Doug DC931 · Emergency Lighting
  > STL - DURING ROUTINE MAINTENANCE, FOUND EGRESS LIGHTS SEAT ROWS 21 TO 23 AND TAILCONE PATHWAY, INOPERATIVE. FOUND EGRESS LIGHT CABLE CONNECTOR, MFG PN 5854-1, DIRTY. CLEANED CABLE CONNECTOR AND LIGHT OPERATION CHECKED NORMAL. CHECK C - 9-2-95 - STL.
- [SDR 96ZZZX1239](https://openairdocs.org/sdr/96ZZZX1239.md): Longeron · cracked · Jan 24, 1996 · N991Z · Doug DC931 · Fuselage Main, Longeron/Stringer
  > STL - DURING CHECK 'C', FOUND.50 INCH CRACK IN LONGERON 4L, LOWER LEG, STA 737. REPAIRED PER SRM 53-02, FIGURE 2A. AIRCRAFT TT: 63,390 HOURS; 75,098 CYCLES.
- [SDR 96ZZZX1238](https://openairdocs.org/sdr/96ZZZX1238.md): Belt Ring · cracked · Jan 24, 1996 · N991Z · Doug DC931 · Fuselage Miscellaneous Structure
  > STL - DURING CHECK 'C', FOUND.50 INCH CRACK AT BOTH ATTACH POINTS TO BELT RING, LONGERON 6R, STA 718. REPAIRED PER SRM 53-02, FIGURE 2A. AIRCRAFT TT: 68,390 HRS; 75,098 CYCLES.
- [SDR 96ZZZX1237](https://openairdocs.org/sdr/96ZZZX1237.md): Longeron · cracked · Jan 24, 1996 · N991Z · Doug DC931 · Fuselage Main, Longeron/Stringer
  > STL - DURING CHECK 'C', FOUND.50 INCH CRACK IN LOWER FLANGE OF LONGERON 7L, STA 699. REPAIRED PER SRM 53-02, FIGURE 2A. AIRCRAFT TT: 63,390 HOURS; 75,098 CYCLES.
- [SDR 96ZZZM219](https://openairdocs.org/sdr/96ZZZM219.md): Longeron · cracked · Jan 24, 1996 · N991Z · Doug DC931 · Fuselage Main, Longeron/Stringer
  > STL - DURING C-CHECK, FOUND.5 INCH CRACK IN LOWER FLANGE OF LONGERON 7L, STATION 699. REPAIRED PER SRM 53-02, FIGURE 2A.
- [SDR 96ZZZM217](https://openairdocs.org/sdr/96ZZZM217.md): Longeron · cracked · Jan 24, 1996 · N991Z · Doug DC931 · Fuselage Main, Longeron/Stringer
  > STL - DURING C-CHECK, FOUND ONE 2 INCH CRACK IN LONGERON 4L, LOWER LEG, STATION 737. REPAIRED PER SRM 53-02, FIGURE 2A.
- [SDR 96ZZZM216](https://openairdocs.org/sdr/96ZZZM216.md): Belt Ring · cracked · Jan 24, 1996 · N991Z · Doug DC931 · Fuselage Main, Frame
  > STL - DURING C-CHECK, FOUND.5 INCH CRACK AT BOTH ATTACH POINTS TO BELTRING, LONGERON 6R, STATION 718. REPAIRED PER SRM 53-02, FIGURE 2A.

## The whole list in SQL

Runs in DuckDB 1.2 or later on the release's Parquet files over HTTPS:

```sql
SELECT sdr_id, difficulty_date, n_number, aircraft_make, aircraft_model, part_name, part_condition, jasc_code, discrepancy
FROM 'https://openairdocs.org/data/latest/faa_service_difficulty_report.parquet'
WHERE n_number = 'N991Z' AND deregistration_id = 'N991Z-2001-08-28'
ORDER BY difficulty_date DESC
```

This list as a web page: https://openairdocs.org/deregistered/N991Z-2001-08-28/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.