Air Tractor AT-401 accident near Idaho Falls, Idaho, May 20, 1998
On May 20, 1998 at about 3:15 pm local time, a Air Tractor AT-401, registered N1009T, was substantially damaged in an accident near Idaho Falls, Idaho. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain clearance from a power transmission line during an aerial application flight. Factors include a power line located just beyond the boundary of the field being sprayed, and the pilot's incorrect judgement of the distance between the wire and his aircraft.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 20, 1998 · about 3:15 pm local time
- Place
- Idaho Falls, Idaho · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Air Tractor AT-401
- Registration
- N1009T · no longer on the register · serial 401-0707
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
According to the pilot, who was maneuvering near the power line while applying chemicals to a field, he had just rolled wings-level and descended for another pass when his left wing contacted the top wire of the power line. He said that he saw the line and thought he had clearance, but the aircraft's wing caught the wire near its tip. He reported that after colliding with the power line, the aircraft struck the ground in a 'cart-wheeling' motion. He further stated that he was accustomed to flying the AT-300, but that he had recently purchased the AT-401, and that this was his first application flight using the new aircraft. It was his opinion that the different size and sight-picture of the 401 had caused him to think he had more clearance from the wire than he actually had.
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: 9,882 hours in all; 9 in this make and model; 12 in the last 90 days; 9 in the last 30 days; 9,761 as pilot in command; 426 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 4,055 hours
- Last inspection: 100-hour inspection, April 21, 1998; 9 hours since
- Maximum gross weight: 6,000 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W 1340-AN2 (piston); 0 hours total
The flight
- Departed from: Osgood ID at 2:30 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 050° at 7 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 50°F (10°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 N1009T 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.