Air Tractor INC AT 401 accident near Wall, South Dakota, June 9, 2015
On June 9, 2015 at about 10:30 pm local time, a 1990 Air Tractor INC AT 401, registered N4549E, was substantially damaged in an accident during takeoff near Wall, South Dakota (Private Airstrip airport). 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 pilot's failure to adjust the airplane's useful load to compensate for the high temperature, which resulted in an insufficient climb rate to clear surrounding terrain, and a runway excursion.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 9, 2015 · about 10:30 pm local time
- Place
- Wall, South Dakota · Private Airstrip · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Air Tractor INC AT 401 UNDESIGNAT, built 1990 · all AT 401s on the register
- Registration
- N4549E · registry record · serial 401-0765
- 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 reported that during takeoff from a private grass airstrip, the airplane would not climb above terrain at the end of the runway and impacted the ground coming to rest in a wheat field. The airplane sustained substantial damage to the right wing, right aileron, and fuselage. The pilot reported the outside air temperature at the time of the accident was 91 degrees Fahrenheit and the airplane was loaded near its maximum gross takeoff weight of 6,000 pounds. The pilot stated, "The load was too heavy for the weather conditions at this time". The pilot reported no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.
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
- Preflight or dispatch event during prior to flight
- Runway excursion during takeoff defining event
- Collision with terrain or object (not controlled flight into terrain) during takeoff
The NTSB's findings
- cause Personnel issues › Task performance › Planning/preparation › Performance calculations › Pilot
- cause Aircraft › Aircraft oper/perf/capability › Aircraft capability › Climb capability › Attain/maintain not possible
- Environmental issues › Conditions/weather/phenomena › Temp/humidity/pressure › High temperature › Effect on equipment
- Aircraft › Aircraft oper/perf/capability › Aircraft capability › Maximum weight › Not specified
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land
- Flight time: 5,152 hours in all; 1,332 in this make and model; 22 in the last 90 days; 22 in the last 30 days; 5,009 as pilot in command
- Last flight review: April 27, 2014
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: sngl
- Injury: no injuries
The aircraft
- Airframe total time: 5,001 hours
- Last inspection: 100-hour inspection, February 20, 2015
- Maximum gross weight: 6,000 lb
- Seats: 1
- Landing gear: fixed
- Engine: Aireaserch/Garrett TPE331-1 (turboprop); 7,020 hours total
The flight
- Departed from: NONE Wall SD at 10:30 pm
- Destination: NONE Wall SD
- Flight plan: none
- Runway 35, 2,750 ft by 150 ft
Weather at the time
- Light: daylight
- Wind: from 320° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 79°F (26°C), dew point 64°F (18°C)
- Altimeter: 29.85 inHg
- Observation at 10:24 pm from KRAP, 31 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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 N4549E 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.