Grumman G-164A accident near Fergus Falls, Minnesota, July 20, 2012
On July 20, 2012 at about 1:00 am local time, a Grumman G-164A, registered N4638, was substantially damaged in an accident during maneuvering (low-alt flying) near Fergus Falls, Minnesota. 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
A total loss of engine power due to a cracked No. 2 cylinder head.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 20, 2012 · about 1:00 am local time
- Place
- Fergus Falls, Minnesota · 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
The pilot was spraying a large corn field when he saw a puff of white smoke come from the engine. He turned toward a road, but about half way through the turn, the engine lost all power. The pilot jettisoned the chemical load and landed in the corn field. Examination of the radial engine revealed the No. 2 cylinder head was cracked. A review of the maintenance logbooks revealed that a mandatory Federal Aviation Administration Airworthiness Directive that required a 100-hour visual inspection to prevent cylinder head cracking, had been complied with at the last annual inspection, but no entries were made that any cracks were observed.
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
What happened, in order
- Loss of engine power (total) during maneuvering (low-alt flying) defining event
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Failure
- Personnel issues › Task performance › Maintenance › Scheduled/routine maintenance › Maintenance personnel
- Personnel issues › Task performance › Inspection › Scheduled/routine inspection › Maintenance personnel
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instrument: airplane
- Flight time: 1,851 hours in all; 829 in this make and model; 240 in the last 90 days; 130 in the last 30 days; 1,814 as pilot in command
- Last flight review: April 28, 2011
- Medical certificate: Class 2
- Seat: left
- Injury: serious injuries
The aircraft
- Airframe total time: 9,012 hours
- Last inspection: annual inspection, March 17, 2012
- Maximum gross weight: 4,500 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W R1340 SERIES (piston); 0 hours total
- Operator: West Central Ag-Air INC
The flight
- Departed from: ETH Wheaton MN
- Destination: Dumont MN
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flig | 1 |
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 docket at the NTSB holds the report as a PDF and the investigation's photographs and documents. This site 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 CEN12LA491.