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).
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 November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 1, 1984 · about 1:10 pm local time · cases in 1984
- Place
- Wyndmere, North Dakota · Thompson · cases near this airport · 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
Connections how this case links to the rest of the register
- N4638: not on the register today · the record of its deregistration
- Grumman G-164 119 registered today · the model family and its accident history
- Grumman 443 aircraft on the register
- Engine: P&W R-985 1,593 aircraft carry this series today · as the NTSB recorded it
- Thompson Private Airport · nearest airport
- Accidents and incidents in North Dakota 581 since 1982 · 59 in the last ten years
- North Dakota 2,493 aircraft registered
- Other NTSB records under N4638 1 records · the number may have belonged to another aircraft at the time
The whole map of how records connect · these connections as data: /graph/accident/DEN84LA206.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.