# Service difficulty reports: N498US, cancelled Aug 8, 2013 A list on [N498US, cancelled Aug 8, 2013](https://openairdocs.org/deregistered/N498US-2013-08-08.md). Matched to this aircraft by N-number and event date, checked against the reported serial number, make and model. Newest first. Page 1 of 7 · 347 reports - [SDR QXEA0200832](https://openairdocs.org/sdr/QXEA0200832.md): Battery · discharged · May 15, 2002 · N498US · Fokker F28MK4000 · Emergency Lighting > PDX- PATH WAY LIGHT ON SEAT ROWS 10-14 ARE INOP. REMOVED AND REPLACED AFT BATTERY CARTRIDGE. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0200833](https://openairdocs.org/sdr/QXEA0200833.md): Connector · defective · May 15, 2002 · N498US · Fokker F28MK4000 · Emergency Lighting > PDX- PATH WAY LIGHTS ON SEATS AT ROW 5-9 WILL NOT TURN OFF. REMOVED AND REPLACED ELECTRICAL CONNECTOR AT AT SEAT 9. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0200734](https://openairdocs.org/sdr/QXEA0200734.md): Sign · inoperative · May 1, 2002 · N498US · Fokker F28MK4000 · Emergency Lighting > SEA- MID CABIN EMERGENCY EXIT SIGNS INOPERATIVE. REMOVED AND REPLACED CABIN EMERGENCY EXIT SIGN. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0200545](https://openairdocs.org/sdr/QXEA0200545.md): Rivet · sheared · Apr 4, 2002 · N498US · Fokker F28MK4000 · Fasteners > PDX - FOUND TWO RIVETS SHEARED OFF ON CENTER WING TO FUSELAGE CLOSING ANGLE ON RIGHT SIDE OF A/C. ONE RIVET WAS 7 INCHES FORWARD OF FRAME 10790, AND ONE RIVET 18 INCHES AFT OF FRAME 10790. MAINTENANCE REMOVED THE DAMAGED CHERRY RIVETS AND INSTALLED CHERRY RI - [SDR QXEA0200544](https://openairdocs.org/sdr/QXEA0200544.md): Pressure Panel · cracked · Apr 4, 2002 · N498US · Fokker F28MK4000 · Fuselage Main, Bulkhead > PDX - CRACK WAS FOUND IN LEFT SIDE OF NOSE LANDING GEAR BAY SIDEWALL JUST FORWARD OF STATION 3050. MAINTENANCE FABRICATED AND INSTALLED A DOUBLER AND SHIM IAW F-28 STRUCTURAL REPAIR MANUAL, 53-02-18. - [SDR QXEA0200454](https://openairdocs.org/sdr/QXEA0200454.md): Apu · leaking · Mar 7, 2002 · N498US · Fokker F28MK4000 · APU Oil System > SEA- SMELLED SMOKE IN THE CABIN WHEN BOARDING THE AIRCRAFT. LAVATORY SMOKE DETECTOR WENT OFF. UPON INSPECTION, FOUND APU ALLOWING OIL INTO BLEED SYSTEM. COMPLIED WITH BLEED AIR SYSTEM CHECK. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0200082](https://openairdocs.org/sdr/QXEA0200082.md): Circuit Board · faulty · Jan 24, 2002 · N498US · Fokker F28MK4000 · Emergency Lighting > SEA- GALLEY EMERGENCY EXIT SIGN INOPERATIVE IN ARM. REPLACED LAMP BOARD. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0200075](https://openairdocs.org/sdr/QXEA0200075.md): Sign · inoperative · Jan 18, 2002 · N498US · Fokker F28MK4000 · Emergency Lighting > SEA- EMERGENCY EXIT SIGN ABOVE COCKPIT DOOR INOPERATIVE. REMOVED AND REPLACED EMERGENCY EXIT SIGN. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0102035](https://openairdocs.org/sdr/QXEA0102035.md): Sign · inoperative · Dec 18, 2001 · N498US · Fokker F28MK4000 · Emergency Lighting > PDX- EMERGENCY EXIT SIGN OVER COCKPIT ENTRANCE HAS SEVERAL BULBS INOPERATIVE. REMOVED AND REPLACED EXIT SIGN. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0101910](https://openairdocs.org/sdr/QXEA0101910.md): Detector · inoperative · Nov 15, 2001 · N498US · Fokker F28MK4000 · Detection System > PDX - LAVATORY SMOKE DETECTOR WILL NOT TEST. REMOVED AND REPLACED SMOKE DETECTOR. OPERATIONAL CHECK IS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0101687](https://openairdocs.org/sdr/QXEA0101687.md): Battery Pack · discharged · Oct 18, 2001 · N498US · Fokker F28MK4000 · Emergency Lighting > PDX - THE AFT 3 CABIN EMERGENCY LIGHTS WILL NOT ILLUMINATE. REMOVED AND REPLACED THE NUMBER 7 BATTERY PACK. OPERATIONAL CHECK IS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0101652](https://openairdocs.org/sdr/QXEA0101652.md): Power Supply · discharged · Oct 13, 2001 · N498US · Fokker F28MK4000 · Emergency Lighting > PDX - LEFT AND RIGHT AFT EVACUATION LIGHTS ON FUSELAGE WING/BELLY ARE INOPERABLE. REMOVED AND REPLACED BATTERY POWER SUPPLY. OPERATIONAL CHECK IS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0101375](https://openairdocs.org/sdr/QXEA0101375.md): Circuit Board · inoperative · Aug 19, 2001 · N498US · Fokker F28MK4000 · Emergency Lighting > BOI - FORWARD CABIN EXIT SIGN HAS BULBS BURNED OUT. REPLACED EXIT SIGN CIRCUIT BOARD IAW F-28 MAINTENANCE MANUAL, 33-50-00, PAGE 412 AND 413. OPERATIONAL CHECK IS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0100905](https://openairdocs.org/sdr/QXEA0100905.md): Sign · inoperative · Jun 4, 2001 · N498US · Fokker F28MK4000 · Emergency Lighting > PDX- FORWARD FACING EXIT SIGN AT ROW 9 HAS 3 LIGHTS BURNED OUT. REMOVED AND REPLACED EXIT SIGN AS REQUIRED. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0100705](https://openairdocs.org/sdr/QXEA0100705.md): Skin · damaged · May 13, 2001 · N498US · Fokker F28MK4000 · Trailing Edge Flaps > PDX - FLIGHT CREW REPORTED SMALL HOLE AT INBOARD SECTION OF RIGHT WING FLAP. REPAIRED HOLE AS PER FOKKER STRUCTURAL REPAIR MANUAL. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0100497](https://openairdocs.org/sdr/QXEA0100497.md): Wire · broken · Apr 17, 2001 · N498US · Fokker F28MK4000 · Light System Wiring > SEA - ESCAPE PATH LIGHTING FOUND INOPERATIVE. FOUND BROKEN WIRE. REPAIRED WITH SPLICE. NO PARTS REPLACED. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0100433](https://openairdocs.org/sdr/QXEA0100433.md): Sign · inoperative · Mar 28, 2001 · N498US · Fokker F28MK4000 · Emergency Lighting > SEA - THE EXIT SIGN ABOVE THE FLIGHT COMPARTMENT DOOR WAS FOUND INOPERATIVE. REMOVED AND REPLACED EXIT SIGN ASSEMBLY. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0100250](https://openairdocs.org/sdr/QXEA0100250.md): Receptacle · defective · Mar 6, 2001 · N498US · Fokker F28MK4000 · Buffet/Galleys > SMF- ELECTRICAL SMELL IN GALLEY. NR 1 COFFEE CIRCUIT BREAKER POPPED. REMOVED AND REPLACED NR 1 HOT JUG RECEPTICAL. INSPECTED, CLEANED AND LUBED NR 2 RECEPTICAL. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0100249](https://openairdocs.org/sdr/QXEA0100249.md): Coffeemaker · malfunctioned · Mar 6, 2001 · N498US · Fokker F28MK4000 · Buffet/Galleys > PDX- NR 1 COFFEE POT CIRCUIT BREAKER POPPED. F/A REPORTED SLIGHT ELECTRICAL SMELL. REMOVED AND REPLACED NR 1 COFFEE POT. RESET CIRCUIT BREAKER. OPERATIONAL CHECK GOOD, AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0100104](https://openairdocs.org/sdr/QXEA0100104.md): Light · inoperative · Feb 11, 2001 · N498US · Fokker F28MK4000 · Emergency Lighting > SEA - EXIT LIGHT GALLEY OVERHEAD INOP. INSTALLED NEW LIGHT ASSEMBLY. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA01000087](https://openairdocs.org/sdr/QXEA01000087.md): Apu · odor · Jan 30, 2001 · N498US · Fokker F28MK4000 · APU Oil System > PDX- OIL SMELL IN CABIN. REMOVED AND REPLACED APU. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA01000080](https://openairdocs.org/sdr/QXEA01000080.md): Oil Tank · odor · Jan 28, 2001 · N498US · Fokker F28MK4000 · APU Oil System > BOI- STRONG FUEL SMELL IN FORWARD CABIN AND GALLEY AREA. REMOVED AND REPLACED APU OIL TANK. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0100081](https://openairdocs.org/sdr/QXEA0100081.md): Unknown · odor · Jan 28, 2001 · N498US · Fokker F28MK4000 · Air Distribution System > PDX- CABIN AND COCKPIT BOTH HAVE STRONG ODOR OF FUEL. ACCOMPLISHED BLEED AIR SYSTEM BLOWOUT OF BOTH AIR CONDITIONING PACK SYSTEMS DURING ENGINE RUN-UP. NO FURTHER FUEL ODOR NOTICED. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0003353](https://openairdocs.org/sdr/QXEA0003353.md): Sign · inoperative · Dec 19, 2000 · N498US · Fokker F28MK4000 · Emergency Lighting > SEA - UPON INSPECTION, FOUND NR 2 OVERHEAD EXIT SIGN TO HAVE INOPERATIVE LAMPS. REMOVED AND REPLACED LAMP BOARD. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0003275](https://openairdocs.org/sdr/QXEA0003275.md): Circuit Board · inoperative · Dec 19, 2000 · N498US · Fokker F28MK4000 · Emergency Lighting > SEA-#2 OVERHEAD EXIT SIGN HAS INOPERATIVE BULBS. REPLACED CIRCUIT BOARD. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0003180](https://openairdocs.org/sdr/QXEA0003180.md): Apu · inoperative · Dec 8, 2000 · N498US · Fokker F28MK4000 · APU Exhaust System > MSO-CABIN FILLED WITH SMOKE, PROBABLE CAUSE IS APU.REMOVED AND REPLACED APU. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0003149](https://openairdocs.org/sdr/QXEA0003149.md): Smoke Detector · inoperative · Nov 28, 2000 · N498US · Fokker F28MK4000 · Smoke Detection > SEA - GROUND PERSONEL FOUND RED WARNING LIGHT ILLUMINATED ON CARGO AREA SMOKE DETECTOR. REMOVED AND REPLACED SMOKE DETECTOR. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0003052](https://openairdocs.org/sdr/QXEA0003052.md): Cover · dislodged · Nov 17, 2000 · N498US · Fokker F28MK4000 · Emergency Lighting > SEA - EXIT LIGHT COVER AT SEAT 9B BECAME DISLODGED. REMOVED AND REPLACED EXIT SIGN ASSEMBLY. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0002557](https://openairdocs.org/sdr/QXEA0002557.md): Sign · inoperative · Sep 17, 2000 · N498US · Fokker F28MK4000 · Emergency Lighting > GEG - FORWARD CABIN EXIT SIGN WAS FOUND TO HAVE SEVERAL LAMPS INOPERATIVE. REMOVED AND REPLACED EXIT SIGN ASSEMBLY. OPERATIONAL CHECKS GOOD, AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0001791](https://openairdocs.org/sdr/QXEA0001791.md): Sign · inoperative · Jun 30, 2000 · N498US · Fokker F28MK4000 · Emergency Lighting > PDX - FORWARD CABIN EMERGENCY EXIT SIGN FOUND TO HAVE BURNT OUT LIGHT SEGMENTS. REMOVED AND REPLACED EXIT SIGN. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0001790](https://openairdocs.org/sdr/QXEA0001790.md): Sign · inoperative · Jun 30, 2000 · N498US · Fokker F28MK4000 · Emergency Lighting > PDX - CENTER OVER HEAD CABIN EMERGENCY EXIT SIGN WAS REPORTED INOPERATIVE. REMOVED AND REPLACED SIGN. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0001545](https://openairdocs.org/sdr/QXEA0001545.md): Light · inoperative · Jun 15, 2000 · N498US · Fokker F28MK4000 · Emergency Lighting > PDX- EVACUATION AND EMERGENCY LIGHTS ON FORWARD FLIGHT ATTENDANT PANEL INTERMITTANT. REMOVED AND REPLACED LIGHT ASSEMBLY IN FORWARD FLIGHT ATTENDANT PANEL. - [SDR QXEA0001544](https://openairdocs.org/sdr/QXEA0001544.md): Light · inoperative · Jun 15, 2000 · N498US · Fokker F28MK4000 · Emergency Lighting > PDX-EVACUATION LIGHT AT SERVICE/EMERGENCY DOOR INOPERATIVE. REMOVED AND REPLACED LIGHT ASSEMBLY AND POWER WIRE FROM BATTERY PACK. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0001426](https://openairdocs.org/sdr/QXEA0001426.md): Circuit Board · inoperative · May 30, 2000 · N498US · Fokker F28MK4000 · Emergency Lighting > GEG - UPON INSPECTION, FOUND FORWARD CABIN OVERHEAD EXIT SIGN WITH BURNT OUT SEGMENTS. REMOVED AND REPLACED CIRCUIT BOARD. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE. - [SDR QXEA0001409](https://openairdocs.org/sdr/QXEA0001409.md): Rib · cracked · May 20, 2000 · N498US · Fokker F28MK4000 · Rudder, Spar/Rib > PDX- RUDDER LEADING EDGE RIB NR 4 HAS A CRACK APPROXIMATELY 1.25 INCH LONG LOCATED AT LEFT HAND SIDE OF RIB. REPAIRED IAW HORIZON AIR EA 4-55-217. - [SDR QXEA0001418](https://openairdocs.org/sdr/QXEA0001418.md): Skin · damaged · May 16, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Plate/Skin > PDX- THREE DEEP CREASES IN VERTICAL SKIN LEFT SIDE BETWEEN FRONT SPAR AND SPAR I, BETWEEN RIB 5.0 AND 3.8. REPAIRED IAW HORIZON AIR EA 4-55-213. - [SDR QXEA0001433](https://openairdocs.org/sdr/QXEA0001433.md): Skin · dented · May 15, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Plate/Skin > PDX-NUMEROUS DENTS 6 INCHES FROM FORWARD LOWER RADIUS OF AFT CARGO DOOR APERTURE. DENTS ARE IN AFT CARGO PIT DOOR APERTURE. REPAIRED IAW FOKKER SRM 51-31-05 AND SRM 51-31-01. - [SDR QXEA0001405](https://openairdocs.org/sdr/QXEA0001405.md): Clip · cracked · May 15, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Structure > PDX- CRACKED CLIP ON FRAME 17565 BETWEEN STRINGERS 7 - 5. REPAIRED IAW FOKKER SRM 53-10-05 PAGE 601A AND 53-01-13 PAGE 4. - [SDR QXEA0001404](https://openairdocs.org/sdr/QXEA0001404.md): Clip · cracked · May 15, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Structure > PDX- CRACKED CLIP ON FRAME 17565 BETWEEN STRINGERS 8 - 9. REPAIRED IAW FOKKER SRM 53-10-05 PAGE 601A. - [SDR QXEA0001403](https://openairdocs.org/sdr/QXEA0001403.md): Clip · cracked · May 15, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Structure > PDX- CRACKED CLIP ON FRAME 17565 BETWEEN STRINGERS 9 - 10. REPAIRED IAW FOKKER SRM 53-10-05 PAGE 601A. - [SDR QXEA0001371](https://openairdocs.org/sdr/QXEA0001371.md): Beam · damaged · May 15, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Structure > PDX- REAR PRESSURE BULKHEAD BEAM III REQUIRES REPAIRED IAW FOKKER SRM 53-02-18 AT AREA OF PREVIOUS REPAIR AT APPROXIMATELY BL 800 LEFT. REPAIRED IAW HORIZON AIR EA 4-53-1055 C. - [SDR QXEA0001360](https://openairdocs.org/sdr/QXEA0001360.md): Stringer · damaged · May 15, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Longeron/Stringer > PDX- STRINGER 71 FORWARD END HAS EDGE DAMAGE. REPAIRED IAW FOKKER SRM 51-10-4 AND 53-01-01 PAGE 5. - [SDR QXEA0001408](https://openairdocs.org/sdr/QXEA0001408.md): Attach Fitting · cracked · May 14, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Attach Fittings > PDX- VERTICAL STABILIZER TO FUSELAGE LEFT HAND CONNECTION ANGLE IS CRACKED AT HI-LOK FASTENER, AT THE NR 2 INTERMEDIATE SPAR. REPAIRED IAW FOKKER SRM 55-31-00 FIGURE 1, 51-31-01 AND 51-31-02. - [SDR QXEA0001402](https://openairdocs.org/sdr/QXEA0001402.md): Frame · tool damage · May 14, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Frame > PDX- THERE IS TOOLING DAMAGE TO CONNECTION ANGLE ON FRAME 16-2 AT STRINGER 34. REPAIRED IAW HORIZON AIR EA 4-53-1158. - [SDR QXEA0001398](https://openairdocs.org/sdr/QXEA0001398.md): Skin · dented · May 14, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Plate/Skin > PDX- THERE IS A DENT IN THE EXTERIOR FUSELAGE SKIN APPROXIMATELY 3 INCHES FORWARD OF THE CUTOUT FOR ACCESS PANEL 41A, ALONG STRINGER 74. REPAIRED IAW FOKKER SRM 51-31-01, 53-02-02 FIGURE 1 AND 53-00-00. - [SDR QXEA0001382](https://openairdocs.org/sdr/QXEA0001382.md): Clip · cracked · May 14, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Structure > PDX- CRACKED CLIP AT FRAME 3820, 25 LEFT OF CL, BELOW FLOORBOARD SUPPORT. REPAIRED IAW FOKKER SRM 51-31-01 AND 51-30-02. - [SDR QXEA0001326](https://openairdocs.org/sdr/QXEA0001326.md): Angle · cracked · May 14, 2000 · N498US · Fokker F28MK4000 · Fuselage Miscellaneous Structure > PDX- POSSIBLE CRACKS AT RIGHT VERTICAL CONNECTION ANGLE RADIATING FROM HI-LOKS AT SPAR II. REPAIRED IAW FOKKER SRM 55-31-00 FIGURE 1 AND 51-30-02. - [SDR QXEA0001416](https://openairdocs.org/sdr/QXEA0001416.md): Skin · dented · May 13, 2000 · N498US · Fokker F28MK4000 · Fuselage Main, Plate/Skin > PDX- ONE DENT 2 INCHES LONG.035 DEEP 8 AFT FRAME 18075 ABOVE STRINGER 63. THIS DENT IS OUT OF LIMITS ASPECT RATIO IS 14 MUST BE GREATER THAN 30. REPAIRED IAW FOKKER SRM 53-02-02 FIGURE 1 AND 53-00-00. - [SDR QXEA0001413](https://openairdocs.org/sdr/QXEA0001413.md): Angle · cracked · May 13, 2000 · N498US · Fokker F28MK4000 · Fuselage Miscellaneous Structure > PDX- THERE IS A CRACK IN THE CONNECTION ANGLE ON THE FORWARD SIDE OF FRAME 17565 AND STRINGER 50. REPAIRED IAW FOKKER SRM 53-10-05 FIGURE 602. - [SDR QXEA0001406](https://openairdocs.org/sdr/QXEA0001406.md): Fastener · loose · May 13, 2000 · N498US · Fokker F28MK4000 · Fuselage Miscellaneous Structure > PDX- LOOSE AND SMOKING HI-LOKS AT RIGHT HAND VERTICAL CONNECTION ANGLE SPAR II. REPAIRED IAW FOKKER SRM 51-30-02. Next page: https://openairdocs.org/deregistered/N498US-2013-08-08/reports.md?page=2 ## 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 = 'N498US' AND deregistration_id = 'N498US-2013-08-08' ORDER BY difficulty_date DESC ``` This list as a web page: https://openairdocs.org/deregistered/N498US-2013-08-08/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.