Grumman G-164A accident near Chamerlain, South Dakota, July 25, 1984
On July 25, 1984 at about 1:00 am local time, a Grumman G-164A, registered N4593, was substantially damaged in an accident near Chamerlain, South Dakota. 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 October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 25, 1984 · about 1:00 am local time
- Place
- Chamerlain, South Dakota · 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
- N4593 · registry record · serial 1082
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
THE PILOT EXPERIENCED AN ENGINE FAILURE AND EXECUTED AN EMERGENCY LANDING ON A NARROW ROAD WHICH RESULTED IN ONE OF THE LANDING GEAR TOUCHING DOWN ON THE SOFT SHOULDER. THE LANDING GEAR FAILED AND SUBSTANTIAL DAMAGE RESULTED. EXAMINATION OF THE ENGINE REVEALED THAT THE CYLINDER SEPERATED DUE TO IMPROPERLY TORQUED STUD BOLTS WHICH ALLOWED AN OVER STRESS CONDITION TO EXIST ON A FEW STUDS THAT WERE PROPERLY TORQUED.
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: commercial pilot
- Ratings: single-engine land
- Flight time: 2,459 hours in all; 610 in this make and model; 382 in the last 90 days; 2,409 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 3,575 hours
- Last inspection: annual inspection, March 3, 1984; 37 hours since
- Maximum gross weight: 3,725 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W 985 AN-1 (piston); 0 hours total
The flight
- Departed from: CHB Chamberlain SD at 12:00 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 135° at 4 knots
- Visibility: 15 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 N4593 the same tail number, which may have belonged to a different aircraft at the time
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 never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.