# NTSB investigations: Maneuvering

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 135 of 378 · 18,851 cases

## Cases, newest first

- [NTSB FTW95FA406](https://openairdocs.org/ntsb/FTW95FA406.md): Martin B-26C · Odessa, TX · Accident · 5 fatal · Field investigation · Final report · Sep 28, 1995 · N5546N · Destroyed
  > the failure of the pilot to maintain minimum airspeed for flight resulting in an inadvertent stall/spin. Factors were the loss of power for undetermined reasons, and the pilot's lack of recent flight experience in the aircraft.
- [NTSB CHI95LA339](https://openairdocs.org/ntsb/CHI95LA339.md): Mcclintic-Piercie KR-1 · Scotts, MI · Accident · 1 fatal · Limited investigation · Final report · Sep 28, 1995 · N9975A · Destroyed
  > the pilot's failure to maintain airspeed.
- [NTSB CHI95LA335](https://openairdocs.org/ntsb/CHI95LA335.md): Bell 206B · Indianapolis, IN · Accident · Minor injuries · Limited investigation · Final report · Sep 28, 1995 · N28SJ · Substantial damage
  > The pilot not maintaining adequate terrain clearance during his maneuvering exercise and his abrupt lowering of the collective. A factor associated with the accident was the pilot's lack of experience.
- [NTSB ATL95LA175](https://openairdocs.org/ntsb/ATL95LA175.md): Schweizer 269C · Hoover, AL · Accident · Serious injuries · Limited investigation · Final report · Sep 27, 1995 · N267RW · Substantial damage
  > The pilot's failure to maintain directional control when he positioned the helicopter in a hover so as to induce a loss of tail rotor effectiveness.
- [NTSB SEA95LA224](https://openairdocs.org/ntsb/SEA95LA224.md): Macphee Vans RV-6 · Jacksonville, OR · Accident · 1 fatal · Limited investigation · Final report · Sep 23, 1995 · N726WM · Destroyed
  > the pilot-in-command's failure to maintain altitude and/or clearance from surrounding terrain after a low pass. The mountainous terrain was a factor.
- [NTSB SEA95LA223](https://openairdocs.org/ntsb/SEA95LA223.md): Eurocopter AS350BA · Crater Lake, OR · Accident · 2 fatal · Limited investigation · Final report · Sep 23, 1995 · N6099Z · Destroyed
  > Failure of the pilot to maintain sufficient altitude/clearance above water, while performing low altitude flight. Factors relating to the accident were: the glassy water condition, and lack of visual cues concerning perception of altitude.
- [NTSB NYC95LA226](https://openairdocs.org/ntsb/NYC95LA226.md): Champion 7KCAB · Auburn, NY · Accident · No injuries · Limited investigation · Final report · Sep 23, 1995 · N6304N · Destroyed
  > the loss of airplane control as a result of a jammed rudder for undetermined reasons.
- [NTSB MIA95LA233](https://openairdocs.org/ntsb/MIA95LA233.md): Air Tractor 301 · Dyer, TN · Accident · No injuries · Limited investigation · Final report · Sep 23, 1995 · N5095S · Substantial damage
  > The pilot-in-command's failure to properly manage the fuel required for the flight, resulting in a total loss of engine power due to fuel exhaustion and subsequent in flight collision with trees and terrain.
- [NTSB MIA95LA227](https://openairdocs.org/ntsb/MIA95LA227.md): Air Tractor AT-301A · Vero Beach, FL · Accident · Minor injuries · Limited investigation · Final report · Sep 21, 1995 · N7304C · Destroyed
  > Failure of company maintenance personnel to comply with a required airworthiness directive, resulting in an in-flight fire and emergency landing. Contributing to the accident was the lack of suitable terrain for the forced landing.
- [NTSB LAX95LA348](https://openairdocs.org/ntsb/LAX95LA348.md): Piper PA-25 · Marana, AZ · Accident · No injuries · Limited investigation · Final report · Sep 21, 1995 · N8551L · Substantial damage
  > the pilot misjudged clearance from the power lines.
- [NTSB FTW95FA399](https://openairdocs.org/ntsb/FTW95FA399.md): Air Tractor AT-502A · Coleman, TX · Accident · 1 fatal · Field investigation · Final report · Sep 21, 1995 · N91969 · Destroyed
  > the pilot's continued flight into adverse weather resulting in spatial disorientation and loss of control. A factor was the pilot's improper weather evaluation and the weather.
- [NTSB SEA95LA227](https://openairdocs.org/ntsb/SEA95LA227.md): Texas Helicopter OH-13E · Yakima, WA · Accident · No injuries · Limited investigation · Final report · Sep 20, 1995 · N38115 · Substantial damage
  > Fatigue failure of the bolt attaching the scissor arm assembly to the pitch control support assembly. The failure of the bolt led to a loss of collective pitch control and reduced rotor RPM.
- [NTSB SEA95LA221](https://openairdocs.org/ntsb/SEA95LA221.md): Bell UH-1L · Grace, ID · Accident · Serious injuries · Limited investigation · Final report · Sep 18, 1995 · N70410 · Destroyed
  > the fatigue failure of the centrifugal impeller and the lack of suitable terrain for a forced landing. Factors contributing to the accident were: the lack of required compliance with the FAA Airworthiness Directive by the operator, the insufficiently defined…
- [NTSB CHI95LA323](https://openairdocs.org/ntsb/CHI95LA323.md): Haugen Kolb Firestar II · Souris, ND · Accident · 1 fatal · Limited investigation · Final report · Sep 17, 1995 · N42996 · Destroyed
  > the pilot's failure to maintain control of the ultralight vehicle.
- [NTSB CHI95FA326](https://openairdocs.org/ntsb/CHI95FA326.md): Piper PA-38-112 · Danville, IN · Accident · 2 fatal · Field investigation · Final report · Sep 16, 1995 · N118AT · Destroyed
  > the pilot-in-command's inadequate recovery while maneuvering.
- [NTSB ATL95LA169](https://openairdocs.org/ntsb/ATL95LA169.md): Air Tractor AT-301 · Plains, GA · Accident · Minor injuries · Limited investigation · Final report · Sep 16, 1995 · N2362D · Substantial damage
  > Failure of the number four cylinder rocker arm housing and pin, which resulted in a closed exhaust valve and loss of engine power.
- [NTSB ANC95FA167](https://openairdocs.org/ntsb/ANC95FA167.md): Cessna 185 · Petersburg, AK · Accident · 2 fatal · Field investigation · Final report · Sep 14, 1995 · N90033 · Destroyed
  > The pilot's failure to maintain sufficient airspeed above the airplane's stall speed. The high terrain and low ceiling (clouds) were related factors.
- [NTSB ANC95TA166](https://openairdocs.org/ntsb/ANC95TA166.md): Bell 206B · Glennallen, AK · Accident · Serious injuries · Final report · Sep 10, 1995 · N84TA · Destroyed
  > The pilot's improper in-flight planing/decision and inadequate supervision of the passenger, which allowed the helicopter's lateral center-of-gravity to be exceeded. Factors relating to the accident were: pressure (compelling influence) on the pilot and…
- [NTSB ANC95LA163](https://openairdocs.org/ntsb/ANC95LA163.md): Piper PA-18 · Palmer, AK · Accident · Minor injuries · Limited investigation · Final report · Sep 10, 1995 · N6996D · Substantial damage
  > Failure of the pilot to maintain adequate altitude/clearance from terrain, during a low pass over a prospective (off-airport) landing area. Factors relating to the accident were: rain and rising/uneven terrain.
- [NTSB FTW95LA385](https://openairdocs.org/ntsb/FTW95LA385.md): Cessna 210F · Montrose, CO · Accident · No injuries · Limited investigation · Final report · Sep 9, 1995 · N1851F · Substantial damage
  > The pilot's inattentiveness to the low fuel supply and his failure to switch fuel tanks in a timely manner. A factor was the lack of suitable terrain for the forced landing.
- [NTSB ANC95LA162](https://openairdocs.org/ntsb/ANC95LA162.md): Cessna 140 · Anchorage, AK · Accident · No injuries · Limited investigation · Final report · Sep 9, 1995 · N89138 · Substantial damage
  > failure of the pilot to maintain sufficient altitude/clearance from terrain during a low pass over a prospective (off-airport) landing area. Factors relating to the accident were: the 'flat' lighting condition, and uneven terrain.
- [NTSB SEA95LA211](https://openairdocs.org/ntsb/SEA95LA211.md): Gift Challenger II · Scappoose, OR · Accident · 2 fatal · Limited investigation · Final report · Sep 8, 1995 · N838TG · Destroyed
  > Failure of the pilot to maintain adequate airspeed, while maneuvering, which resulted in a stall/spin. Although the aircraft recovery parachute had been activated, there was not enough time (or altitude) for it to fully deploy.
- [NTSB SEA95FA212](https://openairdocs.org/ntsb/SEA95FA212.md): Aero Commander 560 · Ketchum, ID · Accident · 2 fatal · Field investigation · Final report · Sep 8, 1995 · N731R · Destroyed
  > The pilot-in-command's failure to maintain adequate airspeed during a turn resulting in a stall/spin. Factors contributing to the accident were the pilot-in-command's becoming geographically disoriented as well as his improper in-flight decision, and…
- [NTSB SEA95FA209](https://openairdocs.org/ntsb/SEA95FA209.md): Cessna 180J · Browning, MT · Accident · 1 fatal · Field investigation · Final report · Sep 7, 1995 · N7820K · Destroyed
  > Clearance from the ground was not maintained while attempting a VFR flight into IMC weather conditions. A factor to the accident was fog.
- [NTSB LAX95LA326](https://openairdocs.org/ntsb/LAX95LA326.md): Hiller UH-12C · Porterville, CA · Accident · Minor injuries · Limited investigation · Final report · Sep 6, 1995 · N1348Z · Substantial damage
  > the flight instructor's inadequate supervision of the flight; the dual student's improper use of the flight controls; and improper remedial action.
- [NTSB FTW95LA379](https://openairdocs.org/ntsb/FTW95LA379.md): Rockwell S-2R · Loop, TX · Accident · No injuries · Limited investigation · Final report · Sep 5, 1995 · N4998X · Substantial damage
  > The pilot's failure to maintain clearance with the power line. A factor was the sun glare light conditions.
- [NTSB CHI95LA306](https://openairdocs.org/ntsb/CHI95LA306.md): Piper PA-11 · Badger, SD · Accident · Serious injuries · Limited investigation · Final report · Sep 5, 1995 · N70613 · Destroyed
  > the pilot's failure to maintain adequate airspeed while making a steep right turn. A contributing factor was the insufficient altitude needed to make a recovery.
- [NTSB SEA95LA208](https://openairdocs.org/ntsb/SEA95LA208.md): Cessna 185F · Salem, OR · Accident · Minor injuries · Limited investigation · Final report · Sep 4, 1995 · N9222H · Substantial damage
  > A loss of power for undetermined reasons and the pilot's failure to maintain airspeed while maneuvering for a forced landing.
- [NTSB NYC95LA214](https://openairdocs.org/ntsb/NYC95LA214.md): Gillet C.P. 328 · Fire Island, NY · Accident · 1 fatal · Limited investigation · Final report · Sep 4, 1995 · N4171G · Destroyed
  > the failure of the pilots to maintain control of the airplane while performing aerobatics.
- [NTSB SEA95FA198](https://openairdocs.org/ntsb/SEA95FA198.md): Beech A24R · Yakima, WA · Accident · 1 fatal · Field investigation · Final report · Sep 3, 1995 · N9726Q · Destroyed
  > The pilot's failure to maintain clearance from a tree. Factors related to the accident were: the pilot's poor judgment and ostentatious display to buzz.
- [NTSB NYC95FA212](https://openairdocs.org/ntsb/NYC95FA212.md): Piper PA-18A-150 · Egg Harbor, NJ · Accident · 1 fatal · Field investigation · Final report · Sep 3, 1995 · N9374D · Destroyed
  > Failure of the pilot to maintain adequate airspeed during pull-up from a banner pickup, which resulted in a stall and collision with trees before recovering from the stall.
- [NTSB CHI95LA302](https://openairdocs.org/ntsb/CHI95LA302.md): Morrow Starduster I · Ottawa, KS · Accident · 1 fatal · Limited investigation · Final report · Sep 3, 1995 · N46565 · Destroyed
  > the pilot's delayed remedial action during the inverted spin maneuver. A factor associated with the accident was the pilot's lack of recent experience in the type operation.
- [NTSB LAX95LA318](https://openairdocs.org/ntsb/LAX95LA318.md): Hiller UH-12E · Dos Palos, CA · Accident · No injuries · Limited investigation · Final report · Sep 1, 1995 · N4027D · Substantial damage
  > the fatigue failure of the tail rotor tension torsion bar plates.
- [NTSB ANC95LA158](https://openairdocs.org/ntsb/ANC95LA158.md): Short Brothers SC-7 · Skwentna, AK · Accident · 1 fatal · Limited investigation · Final report · Sep 1, 1995 · N30GA · Destroyed
  > The pilot's continued VFR flight into instrument meteorological conditions. The weather was a factor.
- [NTSB LAX95FA313](https://openairdocs.org/ntsb/LAX95FA313.md): Bell 206-L1 · Johnsondale, CA · Accident · 2 fatal · Field investigation · Final report · Aug 30, 1995 · N3886J · Destroyed
  > the pilot's failure to maintain an adequate obstacle clearance altitude while operating at a very low level. The aircraft's lack of wire cutters was a factor in this accident.
- [NTSB LAX95LA310](https://openairdocs.org/ntsb/LAX95LA310.md): Bell 206BIII · Carmel Valley, CA · Accident · No injuries · Limited investigation · Final report · Aug 28, 1995 · N206MT · Substantial damage
  > the pilot's failure to maintain an adequate clearance from obstructions while hovering.
- [NTSB FTW95LA361](https://openairdocs.org/ntsb/FTW95LA361.md): Grumman G-164A · Holyoke, CO · Accident · No injuries · Limited investigation · Final report · Aug 28, 1995 · N9650 · Substantial damage
  > the pilot's failure to maintain terrain clearance.
- [NTSB LAX95LA305](https://openairdocs.org/ntsb/LAX95LA305.md): Sikorsky CH-54A · Emigrant Gap, CA · Accident · No injuries · Limited investigation · Final report · Aug 26, 1995 · N64AR · Destroyed
  > a compressor stall in the right engine for an unknown reason, which resulted in a loss of power in that engine; and inadequate crew coordination between the pilot and copilot, which resulted in their failure to ensure that the external load was promptly…
- [NTSB FTW95LA371](https://openairdocs.org/ntsb/FTW95LA371.md): Grumman G-164A · Trumann, AR · Accident · No injuries · Limited investigation · Final report · Aug 26, 1995 · N8783H · Substantial damage
  > The loss of engine power for undetermined reasons. A factor was the lack of suitable terrain available to the pilot to execute the forced landing.
- [NTSB ANC95FA150](https://openairdocs.org/ntsb/ANC95FA150.md): Piper PA-18-150 · Deadhorse, AK · Accident · 2 fatal · Field investigation · Final report · Aug 26, 1995 · N1590R · Substantial damage
  > The pilot's improper in-flight planning and decision by flying into a box canyon.
- [NTSB ANC95LA149](https://openairdocs.org/ntsb/ANC95LA149.md): Cessna 172 · Soldotna, AK · Accident · Serious injuries · Limited investigation · Final report · Aug 24, 1995 · N96911 · Substantial damage
  > The pilot's improper in-flight planning/decision, and his failure to maintain sufficient altitude to assure clearance from obstructions. The downdraft was a related factor.
- [NTSB SEA95LA191](https://openairdocs.org/ntsb/SEA95LA191.md): Schweizer G-164 · Nyssa, OR · Accident · No injuries · Limited investigation · Final report · Aug 23, 1995 · N146KY · Substantial damage
  > the pilot's inadequate ground reconnaissance.
- [NTSB LAX95TA304](https://openairdocs.org/ntsb/LAX95TA304.md): Douglas C-54G · Aubeery, CA · Accident · No injuries · Final report · Aug 23, 1995 · N2742G · Substantial damage
  > failure of the pilot to see and avoid known obstacles along his route of flight. Contributing was the insufficient information given by the pilot in the lead aircraft.
- [NTSB FTW95FA359](https://openairdocs.org/ntsb/FTW95FA359.md): Mooney M20F · Red Cliff, CO · Accident · 2 fatal · Field investigation · Final report · Aug 23, 1995 · N3768N · Destroyed
  > Improper in-flight planning/decision by the flight crew, and their failure to maintain sufficient airspeed over mountainous terrain, which resulted in an inadvertent stall and collision with terrain. Factors relating to the accident were: high density…
- [NTSB FTW95LA358](https://openairdocs.org/ntsb/FTW95LA358.md): Air Tractor AT-401 · Taft, TX · Accident · No injuries · Limited investigation · Final report · Aug 22, 1995 · N9190Q · Destroyed
  > The pilot's diverted attention, which resulted in his failure to assure that clearance was maintained from the transmission line.
- [NTSB ANC95FA147](https://openairdocs.org/ntsb/ANC95FA147.md): Champion 7ECA · Palmer, AK · Accident · 2 fatal · Field investigation · Final report · Aug 22, 1995 · N57393 · Destroyed
  > failure of the pilot to maintain adequate airspeed, while maneuvering at low altitude, which resulted in an inadvertent stall/spin and collision with the terrain.
- [NTSB FTW95LA356](https://openairdocs.org/ntsb/FTW95LA356.md): Enstrom 280C · Houston, TX · Accident · No injuries · Limited investigation · Final report · Aug 21, 1995 · N911BT · Substantial damage
  > The flight instructor's poor judgement, and his disregard of the owner's objection to air taxi into the hangar.
- [NTSB CHI95LA291](https://openairdocs.org/ntsb/CHI95LA291.md): Cessna 140 · Mio, MI · Accident · 1 fatal · Limited investigation · Final report · Aug 21, 1995 · N76429 · Destroyed
  > the pilot's impairment of judgement and performance which led to performing a low altitude maneuver with insufficient altitude for recovery. A factor was the tailwind.
- [NTSB ANC95FA169](https://openairdocs.org/ntsb/ANC95FA169.md): Piper PA-18A · Anchorage, AK · Accident · 1 fatal · Field investigation · Final report · Aug 21, 1995 · N7262D · Destroyed
  > The pilot's improper in-flight planning/decision and failure to maintain adequate clearance or altitude from the mountainous terrain, while maneuvering near an airstrip.
- [NTSB SEA95LA185](https://openairdocs.org/ntsb/SEA95LA185.md): Cessna 177RG · Thompson, UT · Accident · 1 fatal · Limited investigation · Final report · Aug 20, 1995 · N1930Q · Destroyed
  > the pilot's continued flight into instrument meteorological conditions, and his failure to maintain altitude and clearance from the mountainous terrain. Factors contributing to the accident were the fog, low ceilings, and downdraft.

Next page: https://openairdocs.org/ntsb-phases/450/cases.md?page=136

## 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 = 450)
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb-phases/450/cases?page=135

---
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.
