Air Tractor AT-401 accident near N. Ottawa Twp., Minnesota, August 28, 1998
On August 28, 1998 at about 11:45 pm local time, a Air Tractor AT-401, registered N4543F, was destroyed in an accident near N. Ottawa Twp., 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).
The NTSB's probable cause their words, unchanged
A loss of engine power due to a worn piston ring. A related factor was the owner exceeded the manufacturer's recommended engine overhaul.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 28, 1998 · about 11:45 pm local time
- Place
- N. Ottawa Twp., Minnesota · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Air Tractor AT-401
- Registration
- N4543F · no longer on the register · serial AT 401-0787
- Damage
- Destroyed
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
About 5-minutes after the aerial applicator flight had taken off the pilot said, the airplane's engine experienced a partial power loss. He said the airplane '...did not want to climb and began to settle down.' The pilot ejected his chemical load and was maneuvering for a landing when the right wingtip and landing gear struck the ground. The airplane cartwheeled and rolled over the ground before coming to a stop inverted. The on-scene investigation revealed the airplane s engine had 1 cylinder with no compression. Examination showed the piston rings were badly worn and there was no taper to the cylinder. At the time of the accident the engine was about 70-hours beyond the manufacturer's recommended overhaul time. The airplane had received an annual inspection about 4-months before the accident. The engine logbook showed all compression readings were within the manufacturers recommended range.
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: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 7,500 hours in all; 1,000 in this make and model; 300 in the last 90 days; 150 in the last 30 days
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 2,604 hours
- Last inspection: annual inspection, April 30, 1998; 750 hours since
- Maximum gross weight: 7,860 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W 1340 (piston); 0 hours total
The flight
- Departed from: RLA Northfield MN
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 360° at 9 knots
- Visibility: 10 statute miles
- Sky: not recorded; clear
- Temperature: 82°F (28°C), dew point 63°F (17°C)
- Altimeter: 29.00 inHg
- Observation at 10:53 pm from AXN, 33 miles away
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 N4543F 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.