# NTSB investigations: Enroute

NTSB aviation accident and incident investigations since 1962: the probable cause, findings, aircraft, crew, weather and docket of each, linked to the FAA registry and the FAA’s own reports.

Page 121 of 718 · 35,885 cases

## Cases, newest first

- [NTSB LAX07LA114](https://openairdocs.org/ntsb/LAX07LA114.md): Mooney M20B · St. George, UT · Accident · No injuries · Limited investigation · Final report · Mar 18, 2007 · N74503 · Substantial damage
  > Oil contamination of the right magneto. Factors were the airplane owner's failure to comply with manufacturer's service bulletins and overhaul porcedures.
- [NTSB ATL07LA054](https://openairdocs.org/ntsb/ATL07LA054.md): James Walter Hornet · Talbotton, GA · Accident · 1 fatal · Limited investigation · Final report · Mar 18, 2007 · N7XS · Substantial damage
  > The failure of the right main fuel line, resulting in fuel starvation and a loss of engine power.
- [NTSB LAX07CA111](https://openairdocs.org/ntsb/LAX07CA111.md): Cessna 182 · Diamond Lake, OR · Accident · Serious injuries · Data collection · Final report · Mar 17, 2007 · N6462A · Substantial damage
  > Fuel exhaustion due to the pilot's inadequate preflight inspection and failure to verify the fuel supply. A factor was the night lighting condition.
- [NTSB ATL07LA052](https://openairdocs.org/ntsb/ATL07LA052.md): Bell 47G2A · Huntsville, AL · Accident · Minor injuries · Limited investigation · Final report · Mar 17, 2007 · N471KC · Destroyed
  > The loss of engine power due to undetermined reasons.
- [NTSB MIA07LA059](https://openairdocs.org/ntsb/MIA07LA059.md): Robinson R-44-II · Miami, FL · Accident · No injuries · Limited investigation · Final report · Mar 15, 2007 · N196DM · Substantial damage
  > The pilot's failure to maintain sufficient rotor rpm during an autorotative landing, which resulted in a hard landing and separation of the tailboom.
- [NTSB LAX07LA108](https://openairdocs.org/ntsb/LAX07LA108.md): Piper PA-30 · Paris, ID · Accident · Minor injuries · Limited investigation · Final report · Mar 15, 2007 · N7169Y · Substantial damage
  > a loss of power in the right engine for undetermined reasons.
- [NTSB ATL07CA051](https://openairdocs.org/ntsb/ATL07CA051.md): Air Tractor AT-502B · Collinwood, TN · Accident · No injuries · Data collection · Final report · Mar 15, 2007 · N90319 · Substantial damage
  > The pilots improper inflight planning which resulted in a loss of engine power due to fuel exhaustion.
- [NTSB SEA07CA076](https://openairdocs.org/ntsb/SEA07CA076.md): Cessna 182H · Phoenix, AZ · Accident · No injuries · Data collection · Final report · Mar 14, 2007 · N1903X · Substantial damage
  > The pilot's inadequate preflight inspection, resulting in fuel exhaustion and the loss of power. A factor was the sign.
- [NTSB DEN07CA073](https://openairdocs.org/ntsb/DEN07CA073.md): Aerospatiale SA315B · Norwood, CO · Accident · No injuries · Data collection · Final report · Mar 13, 2007 · N926JV · Substantial damage
  > The inflight collision with a bird(s).
- [NTSB DEN07CA072](https://openairdocs.org/ntsb/DEN07CA072.md): Robinson R22 Beta · Broomfield, CO · Accident · No injuries · Data collection · Final report · Mar 13, 2007 · N7681H · Substantial damage
  > The instructor's failure to maintain aircraft control. A contributing factor was the windshear.
- [NTSB NYC07CA076](https://openairdocs.org/ntsb/NYC07CA076.md): Bellanca 17-30A · Farmingdale, NJ · Accident · Minor injuries · Data collection · Final report · Mar 12, 2007 · N404CT · Substantial damage
  > The pilot's failure to verify the amount of fuel onboard before takeoff. Factors in the accident were the airplane being under fueled, the refueler's experience, the airplane's inoperative fuel gauges, unsuitable terrain for landing, and night lighting…
- [NTSB CHI07MA083](https://openairdocs.org/ntsb/CHI07MA083.md): McDonnell Douglas 369FF · Haena, HI · Accident · 1 fatal · Major investigation · Final report · Mar 11, 2007 · N911VC · Substantial damage
  > The fatigue failure of the tail rotor blade root fitting due to a manufacturing defect which resulted in the separation of the tail rotor system and loss of tail rotor control. A contributing factor to the accident were the trees that the helicopter struck…
- [NTSB LAX07FA103](https://openairdocs.org/ntsb/LAX07FA103.md): Piper PA-28-235 · Tooele, UT · Accident · 3 fatal · Field investigation · Final report · Mar 8, 2007 · N9381W · Destroyed
  > The pilot exceeded the design stress limits of the airplane, which resulted in the in-flight separation of the wings and horizontal stabilizers. Contributing to the accident were the night lighting conditions, clouds, turbulence and icing conditions.
- [NTSB CHI07LA080](https://openairdocs.org/ntsb/CHI07LA080.md): Wood Quickie Q-2 · Edwardsville, IL · Accident · 1 fatal · Limited investigation · Final report · Mar 5, 2007 · N89WW · Substantial damage
  > The loss of engine power during cruise due to loose cylinder head bolts/loose cylinders.
- [NTSB LAX07LA099](https://openairdocs.org/ntsb/LAX07LA099.md): Mallian Rocket II · Arvin, CA · Accident · 1 fatal · Limited investigation · Final report · Mar 3, 2007 · N789JM · Destroyed
  > Loss of control during cruise for undetermined reasons.
- [NTSB LAX07CA098](https://openairdocs.org/ntsb/LAX07CA098.md): Mooney M20D · Visalia, CA · Accident · No injuries · Data collection · Final report · Mar 3, 2007 · N6628U · Substantial damage
  > The pilot's inadequate in-flight fuel system management, which resulted in fuel starvation and a loss of engine power.
- [NTSB MIA07LA055](https://openairdocs.org/ntsb/MIA07LA055.md): Cessna 150G · Miami, FL · Accident · Minor injuries · Limited investigation · Final report · Mar 2, 2007 · N682RA · Substantial damage
  > The pilot-in-command's (CFI) continued operation of the airplane with known deficiencies (rough running engine). A factor in the accident was no suitable terrain for a forced landing.
- [NTSB NYC07CA080](https://openairdocs.org/ntsb/NYC07CA080.md): Mooney M20F · Landenberg, PA · Accident · No injuries · Data collection · Final report · Feb 28, 2007 · N3278F · Substantial damage
  > The pilot's improper preflight planning, which resulted in a loss of engine power due to fuel exhaustion, and subsequent forced landing to a field.
- [NTSB DFW07LA078](https://openairdocs.org/ntsb/DFW07LA078.md): Cessna T182T · Athens, TX · Accident · Serious injuries · Limited investigation · Final report · Feb 27, 2007 · N14685 · Substantial damage
  > The loss of engine power as result of the failure of a mechanic to properly check the torque on the input and output fuel lines to the fuel transducer during the manufacturing process. A contributing factor was the lack of suitable terrain for the forced…
- [NTSB MIA07LA054](https://openairdocs.org/ntsb/MIA07LA054.md): Mark Gibson BB Trike · Sarasota, FL · Accident · Serious injuries · Limited investigation · Final report · Feb 24, 2007 · UNREG · Substantial damage
  > The total loss of engine power for undetermined reasons. A factor in the accident was the unsuitable terrain encountered by the pilot during the forced landing.
- [NTSB CHI07LA078](https://openairdocs.org/ntsb/CHI07LA078.md): Boeing 777 · Chicago, IL · Accident · Serious injuries · Limited investigation · Final report · Feb 23, 2007 · N779AN · No damage
  > An in-flight encounter with turbulence during cruise flight.
- [NTSB ATL07LA044](https://openairdocs.org/ntsb/ATL07LA044.md): Piper PA-31-350 · Phenix City, AL · Accident · Serious injuries · Limited investigation · Final report · Feb 20, 2007 · N41077 · Substantial damage
  > Loss of engine power due to fuel starvation, the pilot's inadequate preflight planning, and his misunderstanding of how the fuel system operates. Contributing to the accident was the manufacturers insufficiently defined procedures for low fuel operations,…
- [NTSB MIA07LA050](https://openairdocs.org/ntsb/MIA07LA050.md): Bellanca 17-30A · Fountain, FL · Accident · Serious injuries · Limited investigation · Final report · Feb 17, 2007 · N6641V · Destroyed
  > A loss of engine power due to a cracked engine exhaust muffler. Contributing to the accident were the inadequate inspection procedures of the muffler system and the routing of the "P" leads wiring for the magnetos.
- [NTSB LAX07IA093](https://openairdocs.org/ntsb/LAX07IA093.md): Columbia LC41-550FG · Banning, CA · Incident · No injuries · Incident investigation · Final report · Feb 14, 2007 · N194LF · No damage
  > Jammed aileron flight control during cruise flight due to the presence of foreign object debris, which resulted from the manufacturer's improper processes.
- [NTSB CHI07LA071](https://openairdocs.org/ntsb/CHI07LA071.md): Piper PA-32-300 · Pellston, MI · Accident · Serious injuries · Limited investigation · Final report · Feb 11, 2007 · N4258R · Substantial damage
  > The fatigue failure of the engine cylinder which resulted in a complete loss of engine power, and the unsuitable terrain encountered by the pilot during the subsequent forced landing. Contributing to the accident were the night lighting condition, and trees.
- [NTSB NYC07IA063](https://openairdocs.org/ntsb/NYC07IA063.md): Airbus A-320-232 · New York, NY · Incident · No injuries · Incident investigation · Final report · Feb 10, 2007 · N648JB · No damage
  > The in-flight fire which was caused by the catastrophic failure of a 9-volt battery from an unknown cause.
- [NTSB DEN07CA070](https://openairdocs.org/ntsb/DEN07CA070.md): Mooney M20K · Ingalls, KS · Accident · No injuries · Data collection · Final report · Feb 10, 2007 · N5737M · Substantial damage
  > The pilot's inadequate in-flight planning and decision making, and failure to refuel while en route, resulting in loss of engine power during cruise due to fuel exhaustion. Contributing to the accident was the poor weather at the pilot's destination.
- [NTSB ATL07LA041](https://openairdocs.org/ntsb/ATL07LA041.md): Beech A36 · Brunswick, GA · Accident · No injuries · Limited investigation · Final report · Feb 9, 2007 · N315P · Substantial damage
  > The pilot's failure to activate the electric fuel pump following a loss of engine power for undetermined reasons.
- [NTSB ATL07FA040](https://openairdocs.org/ntsb/ATL07FA040.md): Beech A36 · Hinesville, GA · Accident · 4 fatal · Field investigation · Final report · Feb 9, 2007 · N506BC · Substantial damage
  > The pilot's failure to maintain aircraft control resulting in the in-flight breakup of the airplane due to aerodynamic overload. Contributing to the accident were airframe icing and the pilot's impairment by illegal drugs.
- [NTSB ANC07CA019](https://openairdocs.org/ntsb/ANC07CA019.md): Aero Commander 100 · Manokotak, AK · Accident · No injuries · Data collection · Final report · Feb 8, 2007 · N3889X · Substantial damage
  > The pilot's continued VFR cruise flight into instrument meteorological conditions, which resulted in an in-flight collision with terrain. Factors associated with the accident were fog, low ceilings, snow showers, and snow-covered terrain.
- [NTSB SEA07FA051](https://openairdocs.org/ntsb/SEA07FA051.md): Beech 200 · Belgrade, MT · Accident · 3 fatal · Field investigation · Final report · Feb 7, 2007 · N45MF · Substantial damage
  > The pilot's failure to maintain an adequate altitude and descent rate during a night visual approach. Dark night conditions and mountainous terrain are factors in the accident.
- [NTSB SEA07LA060](https://openairdocs.org/ntsb/SEA07LA060.md): Brown Pitts S-1 · Incline Vlg, NV · Accident · 1 fatal · Limited investigation · Final report · Feb 6, 2007 · N20164 · Substantial damage
  > The airplane collided with a frozen lake for undetermined reasons. Contributing to the accident was the pilot's intentional operation of the airplane while impaired by alcohol and the FAA's failure to obtain additional information about the pilot's…
- [NTSB DFW07CA065](https://openairdocs.org/ntsb/DFW07CA065.md): McDonnell Douglas 600N · Vicksburg, MS · Accident · No injuries · Data collection · Final report · Feb 6, 2007 · N451DL · Substantial damage
  > The loss of engine power due to fuel starvation as result of a fuel transfer check valve stuck in the closed position. A contributing factor was the lack of suitable terrain for the forced landing.
- [NTSB LAX07FA080](https://openairdocs.org/ntsb/LAX07FA080.md): Mooney M20J · Ranchita, CA · Accident · 1 fatal · Field investigation · Final report · Feb 4, 2007 · N201RV · Substantial damage
  > The pilot's failure to maintain terrain clearance during a cruise descent. Contributing to the accident were the dark night lighting conditions and the mountainous terrain.
- [NTSB LAX07LA078](https://openairdocs.org/ntsb/LAX07LA078.md): Republic RC-3 · Julian, CA · Accident · No injuries · Limited investigation · Final report · Feb 2, 2007 · N6248K · Substantial damage
  > The failure of the propeller to crankshaft attachment bolts due to fatigue. A contributing factor was the improper installation of the propeller assembly by maintenance personnel.
- [NTSB CHI07LA063](https://openairdocs.org/ntsb/CHI07LA063.md): Raytheon B200 · Cape Girardeau, MO · Accident · No injuries · Limited investigation · Final report · Feb 2, 2007 · N777AJ · Substantial damage
  > The company pilot's poor judgment before and during the flight, including turning the oxygen system ready switch to the OFF position after he conducted the preflight inspection and using an unapproved checklist, which did not provide guidance for a fractured…
- [NTSB CHI07LA062](https://openairdocs.org/ntsb/CHI07LA062.md): Hallburg Amphibian S21D · Grinnell, IA · Accident · 2 fatal · Limited investigation · Final report · Feb 2, 2007 · N41RH · Substantial damage
  > The inadequate preflight planning/preparation by the pilot in command and the fuel exhaustion during cruise flight. An additional cause was the inadequate forced landing procedure. A contributing factor was the tailwind.
- [NTSB ATL07FA038](https://openairdocs.org/ntsb/ATL07FA038.md): Cessna 172K · Bessemer, AL · Accident · 2 fatal · Field investigation · Final report · Feb 2, 2007 · N7109G · Substantial damage
  > The non-instrument-rated pilot's continued visual flight rules flight into instrument meteorological conditions.
- [NTSB LAX07CA077](https://openairdocs.org/ntsb/LAX07CA077.md): Bombardier DHC-8-103 · Kaunakakai, HI · Accident · Serious injuries · Data collection · Final report · Feb 1, 2007 · N979HA · No damage
  > an in-flight encounter with clear air turbulence, which resulted in a serious injury to a deadheading crewmember.
- [NTSB SEA07LA055](https://openairdocs.org/ntsb/SEA07LA055.md): Cessna 421 · Pocatello, ID · Accident · No injuries · Limited investigation · Final report · Jan 30, 2007 · N4584L · Substantial damage
  > The separation of the bolt that attaches the elevator trim tab actuator rod to the elevator trim tab horn, resulting in violent flutter of the elevator, and eventually to the separation of the inboard half of the right elevator.
- [NTSB NYC07CA060](https://openairdocs.org/ntsb/NYC07CA060.md): Schweizer SGS 2-32 · Bath, PA · Accident · Serious injuries · Data collection · Final report · Jan 29, 2007 · N32BM · Substantial damage
  > The pilot's misjudged altitude/distance while on approach, which resulted in an in-flight collision with trees during an off airport landing. A factor in the accident was the loss of lift.
- [NTSB ATL07FA036](https://openairdocs.org/ntsb/ATL07FA036.md): Cessna T210M · Haddock, GA · Accident · 1 fatal · Field investigation · Final report · Jan 29, 2007 · N761RS · Substantial damage
  > Loss of engine power for undetermined reasons.
- [NTSB DFW07CA059](https://openairdocs.org/ntsb/DFW07CA059.md): Piper PA-46-310P · Madison, MS · Accident · No injuries · Data collection · Final report · Jan 28, 2007 · N6914T · Substantial damage
  > The loss of engine power due to water contamination in the fuel system. A factor was the muddy terrain.
- [NTSB MIA07CA045](https://openairdocs.org/ntsb/MIA07CA045.md): Cessna 172S · Sanford, FL · Accident · No injuries · Data collection · Final report · Jan 27, 2007 · N20956 · Substantial damage
  > The inadvertent inflight collision with a bird resulting in damage to the airplane and the pilot having limited control capability.
- [NTSB DFW07LA061](https://openairdocs.org/ntsb/DFW07LA061.md): Hughes 269A · Fulshear, TX · Accident · Minor injuries · Limited investigation · Final report · Jan 27, 2007 · N8503A · Substantial damage
  > The loss of engine power for undetermined reasons. A contributing factor was the lack of suitable terrain for the forced landing.
- [NTSB LAX07LA075](https://openairdocs.org/ntsb/LAX07LA075.md): Jihlavan KP-5 · Moorpark, CA · Accident · Minor injuries · Limited investigation · Final report · Jan 26, 2007 · N215KP · Substantial damage
  > a partial loss of power for undetermined reasons.
- [NTSB DEN07IA055](https://openairdocs.org/ntsb/DEN07IA055.md): Bombardier CL-600-2B19 · Cripple Creek, CO · Incident · No injuries · Incident investigation · Final report · Jan 25, 2007 · N17337 · Minor damage
  > A fatigue fracture, which resulted in the separation of the No.1 engine fan disk. Contributing factors in the accident were the operators' maintenance personnel lack of training to be able to detect arc-out damage on the fan disk, and the fan disk…
- [NTSB SEA07LA052](https://openairdocs.org/ntsb/SEA07LA052.md): Cessna 172D · Beaver Marsh, OR · Accident · No injuries · Limited investigation · Final report · Jan 23, 2007 · N2599U · Substantial damage
  > The loss of engine power for undetermined reasons. A contributing factor was the lack of suitable terrain for the forced landing.
- [NTSB LAX07CA094](https://openairdocs.org/ntsb/LAX07CA094.md): General Balloon AX-6 · San Martin, CA · Accident · No injuries · Data collection · Final report · Jan 21, 2007 · N2447Z · Substantial damage
  > The pilot's failure to maintain adequate altitude/clearance from power lines.
- [NTSB DEN07FA054](https://openairdocs.org/ntsb/DEN07FA054.md): Piper PA-28-180 · Centennial, WY · Accident · 3 fatal · Field investigation · Final report · Jan 18, 2007 · N43630 · Substantial damage
  > the pilot's inadvertent flight into adverse weather conditions resulting in a loss of aircraft control. Contributing factors include the pilot's improper preflight planning and decision making, the pilot's spatial disorientation, the pilot's lack of night…

Next page: https://openairdocs.org/ntsb-phases/400/cases.md?page=122

## The whole list in SQL

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

```sql
WITH phase_names(main, name) AS (VALUES (100, 'Prior to flight'), (150, 'Standing'), (200, 'Pushback/towing'), (250, 'Taxi'), (300, 'Takeoff'), (350, 'Initial climb'), (400, 'Enroute'), (450, 'Maneuvering'), (500, 'Approach'), (550, 'Landing'), (600, 'Emergency descent'), (650, 'Uncontrolled descent'), (700, 'Post-impact'), (750, 'After landing'), (800, 'Other'), (990, 'Unknown')),
  crosswalk(code, main, name) AS (VALUES (500, 150, 'Standing'), (501, 150, 'Standing - pre-flight'), (502, 150, 'Standing - starting engine(s)'), (503, 150, 'Standing - engine(s) operating'), (504, 150, 'Standing - engine(s) not operating'), (505, 150, 'Standing - idling rotors'), (510, 250, 'Taxi'), (511, 200, 'Taxi - pushback/tow'), (512, 250, 'Taxi - to takeoff'), (513, 250, 'Taxi - from landing'), (514, 250, 'Taxi - aerial'), (520, 300, 'Takeoff'), (521, 300, 'Takeoff - roll/run'), (522, 350, 'Takeoff - initial climb'), (523, 300, 'Takeoff - aborted'), (530, 400, 'Climb'), (531, 400, 'Climb - to cruise'), (540, 400, 'Cruise'), (541, 400, 'Cruise - normal'), (542, 400, 'Maneuvering - holding (IFR)'), (550, 400, 'Descent'), (551, 400, 'Descent - normal'), (552, 600, 'Descent - emergency'), (553, 650, 'Descent - uncontrolled'), (560, 500, 'Approach'), (561, 500, 'Approach - VFR pattern - downwind'), (562, 500, 'Approach - VFR pattern - base turn'), (563, 500, 'Approach - VFR pattern - base leg/base to final'), (564, 500, 'Approach - VFR pattern - final approach'), (565, 500, 'Go-around (VFR)'), (566, 500, 'Approach - IAF to FAF/outer marker (IFR)'), (567, 500, 'Approach - FAF/outer marker to threshold (IFR)'), (568, 500, 'Circling (IFR)'), (569, 500, 'Missed approach (IFR)'), (570, 550, 'Landing'), (571, 550, 'Landing - flare/touchdown'), (572, 550, 'Landing - roll'), (573, 550, 'Landing - aborted'), (574, 550, 'Emergency landing'), (575, 550, 'Emergency landing after takeoff'), (576, 600, 'Emergency descent/landing'), (580, 450, 'Maneuvering'), (581, 450, 'Maneuvering - aerial application'), (582, 450, 'Maneuvering - turn to reverse direction'), (583, 450, 'Maneuvering - turn to landing area (emergency)'), (590, 450, 'Hover'), (591, 450, 'Hover - in ground effect'), (592, 450, 'Hover - out of ground effect'), (600, 800, 'Other'), (610, 990, 'Unknown')),
  current_codes AS (
    SELECT e.case_mkey, TRY_CAST(e."tier1Number" AS INTEGER) AS code,
      row_number() OVER (PARTITION BY e.case_mkey ORDER BY coalesce(e."isDefiningEvent", false) DESC, e.position) AS n
    FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' e
    WHERE e.aircrafts_position = 1 AND e."tier1Number" GLOB '[1-9][0-9]*'
      AND (e."isDefiningEvent" OR e.case_mkey IN (SELECT "mKey" FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' WHERE "isPre1982"))
  ),
  phases AS (
    SELECT case_mkey, 'current' AS scheme, code, CASE WHEN code >= 990 THEN 990 ELSE code // 50 * 50 END AS main
    FROM current_codes WHERE n = 1
    UNION ALL
    SELECT o.case_mkey, 'older', o."phaseOfFlightCode", w.main
    FROM 'https://openairdocs.org/data/latest/ntsb_occurrences.parquet' o JOIN crosswalk w ON w.code = o."phaseOfFlightCode"
    WHERE o.aircrafts_position = 1 AND o."occurrenceNumber" = 1 AND o.case_mkey NOT IN (SELECT case_mkey FROM current_codes)
  ),
  case_phases AS (
    SELECT p.*, c."eventDate", c."highestInjuryLevel" = 'Fatal' AS fatal, a.aircraft_model_code
    FROM phases p JOIN 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c ON c."mKey" = p.case_mkey
    LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = p.case_mkey AND a.position = 1
    WHERE c."eventDate" >= DATE '1962-01-01' AND p.main IN (SELECT main FROM phase_names)
  )
SELECT c."ntsbNumber", c."eventDate", c."eventType", c."eventCity", c."eventStateOrRegion", a.n_number, a."aircraftMake", a."aircraftModel", c."highestInjuryLevel", c."totalFatal", c."completionStatus", c.report_url
FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = c."mKey" AND a.position = 1
WHERE c."mKey" IN (SELECT case_mkey FROM case_phases WHERE main = 400)
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb-phases/400/cases?page=121

---
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.