Grumman G-164A accident near Wyndmere, North Dakota, July 1, 1984
On July 1, 1984 at about 1:10 pm local time, a Grumman G-164A, registered N4638, was substantially damaged in an accident near Wyndmere, North Dakota (Thompson airport). It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 1, 1984 · about 1:10 pm local time
- Place
- Wyndmere, North Dakota · Thompson · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Grumman G-164A · all G-164As on the register
- Registration
- N4638 · no longer on the register · serial 1071
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
SOD WAS WORN FROM THE MIDDLE OF THE STRIP & THE STRIP WAS WET. THEREFORE, THE PLT ELECTED TO USE THE LEFT SIDE OF THE SOD STRIP FOR TAKEOFF. DURING THE TAKEOFF ROLL, THE LEFT SPRAY BOOM DRAGGED INTO WHEAT THAT WAS GROWING BESIDE THE RWY & THE ACFT VEERED LEFT. STRIPS OF WHEAT ABOUT 30 FT WIDE HAD BEEN PLANTED ON EACH SIDE OF THE RWY. AFTER CROSSING THE WHEAT, THE ACFT WENT INTO A WET BEAN FIELD & NOSED OVER. THE PLT WAS UNAWARE THAT THE BOOM HAD DRAGGED IN THE WHEAT & VEERED THE ACFT UNTIL AFTER THE ACCIDENT.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 486 hours in all; 192 in this make and model; 249 in the last 90 days; 366 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 4,500 hours
- Last inspection: annual inspection, March 15, 1984
- Maximum gross weight: 3,750 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W R-985 (piston); 0 hours total
The flight
- Flight plan: none
- Runway 36, 2,600 ft by 60 ft
Weather at the time
- Light: daylight
- Visibility: 60 statute miles
- Sky: clear
- Temperature: 75°F (24°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N4638 the same tail number, which may have belonged to a different aircraft at the time
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number DEN84LA206.