Air Tractor INC AT 602 accident near Stirum, North Dakota, June 29, 2017
On June 29, 2017 at about 12:40 pm local time, a 2010 Air Tractor INC AT 602, registered N4196Y, was destroyed in an accident during maneuvering (low-alt flying) near Stirum, North Dakota (Lisbon Airport). It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person was killed. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
The pilot's decision to attempt flight with low-level fog in the area, which resulted in an encounter with instrument meteorological conditions and impact with terrain.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 29, 2017 · about 12:40 pm local time
- Place
- Stirum, North Dakota · Lisbon Airport · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Air Tractor INC AT 602 NO SERIES, built 2010 · all AT 602s on the register
- Registration
- N4196Y · no longer on the register · serial 602-1183
- Damage
- Destroyed
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
An employee of the operator reported that the planned aerial application flight was delayed about 2 hours while the pilot waited for the weather conditions to improve. The pilot had spoken with individuals by phone before the flight in an attempt to assess the local conditions. The visibility at the airport was about 1-1/2 miles when the pilot departed. A witness reported that she was sitting on her patio when she heard the airplane. The sound of the engine was normal, "not anything unusual at all." She observed the airplane emerge from the fog and "within seconds" impact the ground. The airplane was level or descending slightly and did not appear to change its flight path before impacting gradually rising terrain. She noted that the airplane did not appear to be out of control, nor did it seem that anything was wrong mechanically. She recalled that it was "very, very foggy" at the time, with about 200 yards visibility. There was no precipitation and little or no wind at the time. A postaccident examination did not reveal any anomalies consistent with a preimpact failure or malfunction. It is likely that the pilot encountered instrument meteorological conditions while operating at a low level and inadvertently impacted the terrain.
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
- VFR encounter with IMC during maneuvering (low-alt flying) defining event
- Loss of visual reference during maneuvering (low-alt flying)
- Controlled flight into terrain or object (CFIT) during maneuvering
The NTSB's findings
- cause Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Pilot
- cause Environmental issues › Conditions/weather/phenomena › Ceiling/visibility/precip › Low visibility › Effect on operation
- cause Environmental issues › Conditions/weather/phenomena › Ceiling/visibility/precip › Fog › Effect on operation
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 15,000 hours in all; 245 in the last 90 days
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: sngl
- Injury: fatal
The aircraft
- Airframe total time: 4,278.4 hours
- Last inspection: annual inspection, April 2, 2017; 123 hours since
- Maximum gross weight: 12,500 lb
- Seats: 1
- Landing gear: fixed
- Engine: Pratt & Whitney Canada PT6A-60AG (turboprop); 4,278 hours total
- Operator: Wilbur Ellis Co
The flight
- Departed from: 6L3 Lisbon ND at 12:00 pm
- Destination: 6L3 Lisbon ND
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 9 statute miles
- Sky: overcast at 500 ft
- Temperature: 63°F (17°C), dew point 61°F (16°C)
- Altimeter: 29.79 inHg
- Observation at 12:35 pm from GWR, 8 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
12 documents, released by the NTSB on August 28, 2018. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Witness Statements | PDF, 4 pages | View Download |
| 2 | Accident Site Diagram (Provided by FAA) | PDF, 1 page | View Download |
| 3 | Report Photos | PDF, 7 pages | View Download |
| 4 | Summary of Airplane Examination | PDF, 3 pages | View Download |
| 5 | Maintenance Records - Airframe | PDF, 13 pages | View Download |
| 6 | Maintenance Records - Engine | PDF, 31 pages | View Download |
| 7 | Maintenance Records - Propeller | PDF, 12 pages | View Download |
| 8 | Maintenance Records - Ad Compliance | PDF, 4 pages | View Download |
| 9 | Weather Documentation | PDF, 4 pages | View Download |
| 10 | Agricultural Association "Fly Safe" Advisory Bulletin | PDF, 1 page | View Download |
| 11 | Toxicological Report | PDF, 1 page | View Download |
| 12 | Statement of Party Representatives to NTSB Investigation | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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.
