# NTSB investigations: Approach

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 134 of 420 · 20,992 cases

## Cases, newest first

- [NTSB DCA94MA065](https://openairdocs.org/ntsb/DCA94MA065.md): Douglas DC-9-31 · Charlotte, NC · Accident · 37 fatal · Class 1 · Major · Final report · Jul 2, 1994 · N954VJ · Destroyed
  > 1) The flightcrew's decision to continue an approach into severe convective activity that was conducive to a microburst; 2) the flightcrew's failure to recognize a windshear situation in a timely manner; 3)the flightcrew's failure to establish and maintain…
- [NTSB CHI94LA220](https://openairdocs.org/ntsb/CHI94LA220.md): Cessna 182E · Garden City, KS · Accident · Minor injuries · Limited investigation · Final report · Jul 2, 1994 · N901JM · Substantial damage
  > fuel exhaustion for reason or reasons undetermined. A factor was the rough/uneven terrain.
- [NTSB ANC94IA075](https://openairdocs.org/ntsb/ANC94IA075.md): Boeing 737-400 · Juneau, AK · Incident · No injuries · Incident investigation · Final report · Jul 2, 1994 · N769AS · 2 aircraft · No damage
  > The failure of the local controller to exercise his responsibility to have each aircraft adjust its flightpath to remain clear of the other, and the failure of the pilot of the Cessna 185 to maintain adequate visual separation from the Boeing 737.
- [NTSB BFO94LA123](https://openairdocs.org/ntsb/BFO94LA123.md): Schweizer 2-33 · Waynesville, OH · Accident · No injuries · Limited investigation · Final report · Jun 29, 1994 · N65807 · Substantial damage
  > The instuctors inadequate supervision of the student who misjudged distance/altitude.
- [NTSB BFO94LA119](https://openairdocs.org/ntsb/BFO94LA119.md): Piper PA-12 · Germansville, PA · Accident · Serious injuries · Limited investigation · Final report · Jun 28, 1994 · N3807M · Substantial damage
  > The pilot failed to maintain a proper descent rate which resulted in an undershoot.
- [NTSB BFO94FA120](https://openairdocs.org/ntsb/BFO94FA120.md): Beech 76 · Elizabeth, PA · Accident · 2 fatal · Field investigation · Final report · Jun 28, 1994 · N6004E · Destroyed
  > 1) The failure of the pilot-in-command (CFI) to provide adequate supervision of the dual student during a simulated single-engine approach, and 2) his failure to perform remedial action. This led to a loss of aircraft control in close proximity to the ground.…
- [NTSB CHI94FA209](https://openairdocs.org/ntsb/CHI94FA209.md): Cameron CAN-56 · West Chicago, IL · Accident · Serious injuries · Field investigation · Final report · Jun 25, 1994 · N20367 · Destroyed
  > the pilots failure to maintain vertical clearance above powerlines which bordered the field in which he intended to land. A factor associated with the accident were the powerlines.
- [NTSB ATL94LA125](https://openairdocs.org/ntsb/ATL94LA125.md): Cessna 172 · Kitty Hawk, NC · Accident · Serious injuries · Limited investigation · Final report · Jun 25, 1994 · N54920 · Substantial damage
  > The pilot's improper compensation for the wind conditions, his improper recovery from a bounced landing, and the inadvertent stall. Factors were the wind conditions and the trees that bounded the runway.
- [NTSB ANC94LA071](https://openairdocs.org/ntsb/ANC94LA071.md): Piper PA-18-150 · Fairbanks, AK · Accident · No injuries · Limited investigation · Final report · Jun 25, 1994 · N9869D · Substantial damage
  > The pilot's inadequate compensation for the wind conditions during the landing. The gusty wind condition was a factor.
- [NTSB DCA94MA061](https://openairdocs.org/ntsb/DCA94MA061.md): Learjet 25D · Chantilly, VA · Accident · 12 fatal · Class 1 · Major · Final report · Jun 18, 1994 · XABBA · Destroyed
  > The poor decisionmaking, poor airmanship, and relative inexperience of the captain in initiating and continuing an unstabilized instrument approach that led to a descent below the authorized altitude without visual contact with the runway environment.…
- [NTSB BFO94LA106](https://openairdocs.org/ntsb/BFO94LA106.md): Mooney M20C · Leesburg, VA · Accident · No injuries · Limited investigation · Final report · Jun 18, 1994 · N6679U · Substantial damage
  > The pilot's failure to maintain the minimum descent altitude until the published approach fix. Factors related to the accident was pilot fatigue, low ceilings, obscuration, and fog.
- [NTSB BFO94FA103](https://openairdocs.org/ntsb/BFO94FA103.md): Beech A-36 · Brainerd, MN · Accident · 3 fatal · Field investigation · Final report · Jun 17, 1994 · N1525G · Destroyed
  > The pilot's failure to follow the published missed approach procedure, and his failure to obtain and/or maintain adequate altitude to avoid collision with the terrain. Factors in the accident were: the pilot's lack of instrument flying experience, and the…
- [NTSB FTW94LA199](https://openairdocs.org/ntsb/FTW94LA199.md): Cessna T210N · Santa Teresa, NM · Accident · No injuries · Limited investigation · Final report · Jun 16, 1994 · N199CH · Substantial damage
  > A power loss due to engine driven fuel pump failure. A factor was the lack of suitable terrain for a forced landing.
- [NTSB FTW94LA194](https://openairdocs.org/ntsb/FTW94LA194.md): Cessna 177 · Watonga, OK · Accident · No injuries · Limited investigation · Final report · Jun 13, 1994 · N2867X · Substantial damage
  > Was the pilot's failure to maintain the proper glidepath, his failure to compensate for existing wind conditions, and his failure to maintain clearance with the fence. A factor was the weather.
- [NTSB LAX94LA253](https://openairdocs.org/ntsb/LAX94LA253.md): Schumacher Swearingen SX-300 · Kingman, AZ · Accident · No injuries · Limited investigation · Final report · Jun 12, 1994 · N2H · Substantial damage
  > the pilot's inadvertent raising the flaps during a go-around attempt. A factor in the accident was the gusty crosswind condition.
- [NTSB ATL94LA120](https://openairdocs.org/ntsb/ATL94LA120.md): Beech P35 · Bluffton, SC · Accident · No injuries · Limited investigation · Final report · Jun 12, 1994 · N982Q · Substantial damage
  > A loss of engine power due to oil starvation. This resulted from an undertorqued condition of the oil filter adapter, and the subsequent fretting of the adapter threads.
- [NTSB FTW94LA190](https://openairdocs.org/ntsb/FTW94LA190.md): Piper PA-24-250 · Canton, TX · Accident · Serious injuries · Limited investigation · Final report · Jun 9, 1994 · N5632P · Destroyed
  > Was the undershoot of the runway threshold due to the pilot's failure to attain the proper touchdown point, and his failure to compensate for the wind condition. A factor was the crosswind.
- [NTSB LAX94LA237](https://openairdocs.org/ntsb/LAX94LA237.md): Cessna 152 · Upper Lake, CA · Accident · Serious injuries · Limited investigation · Final report · Jun 4, 1994 · N94509 · Substantial damage
  > The pilot's failure to maintain adequate airspeed during a go- around. Contributing factors were the pilot's delayed remedial action in initiating the go-around and his improper use of the carburetor heat during the attempted initial climb.
- [NTSB CHI94LA187](https://openairdocs.org/ntsb/CHI94LA187.md): Beech C-23 · Gary, IN · Accident · No injuries · Limited investigation · Final report · Jun 4, 1994 · N18893 · Substantial damage
  > Improper preflight planning and preparation by the pilot-in-command which resulted in fuel exhaustion. A factor associated with the accident was the delay in emergency procedures by the pilot-in-command.
- [NTSB BFO94LA089](https://openairdocs.org/ntsb/BFO94LA089.md): Cessna 150 · Troy, NY · Accident · Minor injuries · Limited investigation · Final report · Jun 4, 1994 · N2480J · Destroyed
  > The pilot's inadequate compensation for the wind conditions and failure to maintain alignment with the runway which resulted in an inflight collision with a tree. A factor is crosswinds.
- [NTSB MIA94LA152](https://openairdocs.org/ntsb/MIA94LA152.md): Cessna 210L · Pahokee, FL · Accident · No injuries · Limited investigation · Final report · May 31, 1994 · N76GH · Substantial damage
  > The improper positioning of the fuel selector valve by the pilot-in-command which caused an engine failure due to fuel starvation at an altitude too low for restart procedures.
- [NTSB LAX94LA230](https://openairdocs.org/ntsb/LAX94LA230.md): Piper PA-34-200 · Chino, CA · Accident · No injuries · Limited investigation · Final report · May 31, 1994 · N4810T · Substantial damage
  > The right engine's failure for undetermined reasons to respond to throttle command during a go-around attempt, and both pilot's failure to maintain directional control of the aircraft. Inadequate supervision of the flight by the CFI is also considered a cause.
- [NTSB FTW94LA189](https://openairdocs.org/ntsb/FTW94LA189.md): Beech 35 · Mckinney, TX · Accident · No injuries · Limited investigation · Final report · May 29, 1994 · N3956N · Substantial damage
  > The ailerons being locked by a foreign object.
- [NTSB SEA94FA129](https://openairdocs.org/ntsb/SEA94FA129.md): Cessna 182B · Rock Springs, WY · Accident · 3 fatal · Field investigation · Final report · May 28, 1994 · N2582G · Destroyed
  > An excessive descent rate in the turn from base to final. Factors include a dark night, high winds, and the pilot's fatigue from his flight and ground schedule the day of the accident.
- [NTSB ATL94LA107](https://openairdocs.org/ntsb/ATL94LA107.md): Cessna 172N · Hartford, AL · Accident · No injuries · Limited investigation · Final report · May 26, 1994 · N73846 · Substantial damage
  > The student pilot's inadequate compensation for gusting wind conditions during the approach to land. Factors were the instructor pilot's inadequate supervision of his student, the gusting wind conditions, and the trees located in close proximity to the runway.
- [NTSB ANC94LA057](https://openairdocs.org/ntsb/ANC94LA057.md): Cessna 152 · Kenai, AK · Accident · Minor injuries · Limited investigation · Final report · May 24, 1994 · N94583 · Destroyed
  > Fuel exhaustion as a result of the student pilot-in-command's failure to refuel. The lack of suitable terrain for a forced landing was a factor.
- [NTSB MIA94LA147](https://openairdocs.org/ntsb/MIA94LA147.md): Ercoupe 415D · Boynton Beach, FL · Accident · Minor injuries · Limited investigation · Final report · May 22, 1994 · N93763 · Substantial damage
  > Inadvertent use of the mixture control while on final approach to land. Contributing to the accident was the separation of the mixture control cable from the carburetor.
- [NTSB ATL94LA103](https://openairdocs.org/ntsb/ATL94LA103.md): Fairchild M-62 · Hendersonville, NC · Accident · Serious injuries · Limited investigation · Final report · May 22, 1994 · N61845 · Destroyed
  > The failure of the pilot to maintain airspeed while maneuvering in the traffic pattern, resulting in an inadvertent stall.
- [NTSB NYC94LA089](https://openairdocs.org/ntsb/NYC94LA089.md): Townsend, H.L. Briegled BG-12A · Readington, NJ · Accident · 1 fatal · Limited investigation · Final report · May 21, 1994 · N6552N · Destroyed
  > The pilot failed to maintain airspeed while maneuvering which resulted in an inadvertent stall/spin. A factor was the lack of experience in the make and model of glider.
- [NTSB NYC94LA088](https://openairdocs.org/ntsb/NYC94LA088.md): Aeronca 11AC · Berwick, ME · Accident · 1 fatal · Limited investigation · Final report · May 21, 1994 · N3167E · Destroyed
  > The pilot's inadequate preflight which fail to detect proper operation of the elevator which resulted in the loss of control inflight. A factor is inadequate maintenance which consisted of misrigging of the elevator flight controls.
- [NTSB NYC94LA087](https://openairdocs.org/ntsb/NYC94LA087.md): Lutz Acro Sport II · Hornell, NY · Accident · No injuries · Limited investigation · Final report · May 21, 1994 · N5181V · Substantial damage
  > The pilot's failure to maintain a proper glidepath. A factor in this accident was the pilot's lack of total experience in this type of airplane.
- [NTSB FTW94LA169](https://openairdocs.org/ntsb/FTW94LA169.md): Cessna 182 · Bryan, TX · Accident · Minor injuries · Limited investigation · Final report · May 21, 1994 · N6372A · Substantial damage
  > The pilot's failure to refuel resulting in a total loss of engine power due to fuel exhaustion. A factor was the lack of suitable terrain for the forced landing.
- [NTSB CHI94LA167](https://openairdocs.org/ntsb/CHI94LA167.md): Piper PA-12 · Wausaukee, WI · Accident · Serious injuries · Limited investigation · Final report · May 21, 1994 · N7867H · Substantial damage
  > the pilot's inadequate preflight of the airplane.
- [NTSB LAX94LA221](https://openairdocs.org/ntsb/LAX94LA221.md): Bell 206A · Ukiah, CA · Accident · Minor injuries · Limited investigation · Final report · May 20, 1994 · N206HS · Destroyed
  > the pilot's inadequate compensation for the existing wind conditions which resulted in a loss of tail rotor effectiveness event and a subsequent loss of directional control.
- [NTSB SEA94LA119](https://openairdocs.org/ntsb/SEA94LA119.md): Hallstrom BD-5B · St. George, UT · Accident · 1 fatal · Limited investigation · Final report · May 17, 1994 · N224FH · Destroyed
  > Carburetor contamination and low output, and the pilot's improper decision to attempt to continue the approach. A factor was the pilot's lack of recent flight experience.
- [NTSB ATL94LA101](https://openairdocs.org/ntsb/ATL94LA101.md): Cessna 152 · Andrews, SC · Accident · No injuries · Limited investigation · Final report · May 16, 1994 · N211SP · Substantial damage
  > The failure of the pilot to maintain directional control of the aircraft.
- [NTSB NYC94LA081](https://openairdocs.org/ntsb/NYC94LA081.md): Let Super Blanik L-33 · New Castle, VA · Accident · No injuries · Limited investigation · Final report · May 15, 1994 · N23BR · Substantial damage
  > The pilot's improper use of the flight controls resulting in failure to maintain a proper descent rate during the approach for landing. A factor in this accident was the pilot's lack of total experience in this type of glider.
- [NTSB NYC94LA080](https://openairdocs.org/ntsb/NYC94LA080.md): Davis DK-1 · East Haddam, CT · Accident · No injuries · Limited investigation · Final report · May 15, 1994 · N158Y · Substantial damage
  > The pilot's failure to maintain the proper glidepath during landing approach.
- [NTSB MIA94FA141](https://openairdocs.org/ntsb/MIA94FA141.md): Beech 95-55 · New Port Richey, FL · Accident · 1 fatal · Field investigation · Final report · May 15, 1994 · N9319Y · Destroyed
  > The pilot's feathering of the wrong propeller after an engine failure for undetermined reason(s).
- [NTSB FTW94LA157](https://openairdocs.org/ntsb/FTW94LA157.md): Piper PA-28R-200 · San Antonio, TX · Accident · Serious injuries · Limited investigation · Final report · May 15, 1994 · N56971 · Destroyed
  > The pilot continued flight into known adverse weather. The thunderstorm activity was a factor.
- [NTSB ATL94FA099](https://openairdocs.org/ntsb/ATL94FA099.md): Beech 58 · Monroe, NC · Accident · Serious injuries · Field investigation · Final report · May 15, 1994 · N66Q · Substantial damage
  > The pilot's inadequate pre-flight inspection.
- [NTSB MIA94LA139](https://openairdocs.org/ntsb/MIA94LA139.md): Cessna 172P · Fernandina, FL · Accident · Minor injuries · Limited investigation · Final report · May 14, 1994 · N99998 · Substantial damage
  > The pilot in command's improper use of flight controls and his failure to maintain airspeed resulting in an inadvertent stall and uncontrolled descent to ground impact.
- [NTSB FTW94LA161](https://openairdocs.org/ntsb/FTW94LA161.md): Cessna 150J · Del Rio, TX · Accident · No injuries · Limited investigation · Final report · May 14, 1994 · N51150 · Substantial damage
  > Fuel exhaustion induced power loss due to the pilot's inaccurate fuel consumption calculations. The lack of suitable terrain for the forced landing was a factor.
- [NTSB CHI94FA157](https://openairdocs.org/ntsb/CHI94FA157.md): Bellanca 17-30A · Camdenton, MO · Accident · 4 fatal · Field investigation · Final report · May 14, 1994 · N4226B · Destroyed
  > The pilot's failure to maintain control of the aircraft. A factor was his lack of experience flying in actual instrument flight conditions.
- [NTSB MIA94LA135](https://openairdocs.org/ntsb/MIA94LA135.md): Beech A35 · St. Petersburg, FL · Accident · No injuries · Limited investigation · Final report · May 10, 1994 · N620B · Substantial damage
  > Failure of the pilot-in-command to maintain airspeed and proper glidepath resulting in the in-flight collision with trees short of the airport property.
- [NTSB FTW94LA185](https://openairdocs.org/ntsb/FTW94LA185.md): Cessna 195 · Ama, LA · Accident · No injuries · Limited investigation · Final report · May 8, 1994 · N999V · Substantial damage
  > The pilot-in-command's failure to maintain adequate airspeed above the aerodynamic stall speed.
- [NTSB ATL94FA093](https://openairdocs.org/ntsb/ATL94FA093.md): Nord 1101 · Spartanburg, SC · Accident · 1 fatal · Field investigation · Final report · May 7, 1994 · N1101A · Destroyed
  > The pilot's failure to maintain adequate airspeed while maneuvering for an emergency landing. A factor in the accident was an inflight fire from an undetermined source.
- [NTSB LAX94LA210](https://openairdocs.org/ntsb/LAX94LA210.md): Schweizer SGS 1-34 · Hemet, CA · Accident · 1 fatal · Limited investigation · Final report · May 3, 1994 · N1163S · Destroyed
  > the pilot's failure to maintain an adequate airspeed while maneuvering in the traffic pattern, which resulted in an inadvertent stall/spin. A factor in the accident was the pilot's low total flight time.
- [NTSB SEA94FA111](https://openairdocs.org/ntsb/SEA94FA111.md): Cessna TU206G · Gold Bar, WA · Accident · Serious injuries · Field investigation · Final report · Apr 30, 1994 · N732JK · Substantial damage
  > Electrical system short. Factors to the accident were: mountainous terrain and procedures/directives not followed.
- [NTSB MIA94LA130](https://openairdocs.org/ntsb/MIA94LA130.md): Air Creation GTX Trike · Englewood, FL · Accident · Serious injuries · Limited investigation · Final report · Apr 30, 1994 · UNREG · Substantial damage
  > Was the failure of the pilot-in-command to maintain airspeed resulting in an inadvertent stall at an altitude insufficient for recovery.

Next page: https://openairdocs.org/ntsb-phases/500/cases.md?page=135

## 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 = 500)
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb-phases/500/cases?page=134

---
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.