Air Tractor AT-400 accident near Balko, Oklahoma, August 5, 2013
On August 5, 2013 at about 3:15 pm local time, a 1982 Air Tractor AT-400, registered N3159B, was destroyed in an accident during enroute (cruise) near Balko, Oklahoma. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure maintain clearance from a meteorological tower while en route at a low altitude. Contributing to the accident was the sun's glare.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 5, 2013 · about 3:15 pm local time
- Place
- Balko, Oklahoma · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Air Tractor AT-400, built 1982
- Registration
- N3159B · no longer on the register · serial 400-0462
- Damage
- Destroyed
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
The commercial pilot was en route from a private airstrip to a nearby field to apply herbicide and flying about 150 feet agl, when the airplane struck a 197-foot meteorological tower (MET) about 35 feet from its top. A survey of the accident scene revealed that the sun was ahead of and to the right of the airplane's flight path and likely obstructed the pilot's ability to see the tower. An examination of the airplane did not reveal any preimpact anomalies. The NTSB recently concluded that, due to their rapid construction and lack of conspicuity, METs pose a threat to pilots who conduct low-altitude operations and recommended required registration, marking, and—where feasible—lighting of these structures in order to aid pilots in avoiding them.
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
- Controlled flight into terrain or object (CFIT) during enroute (cruise) defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Personnel issues › Physical › Sensory ability/limitation › Visual function › Pilot
- factor Environmental issues › Conditions/weather/phenomena › Light condition › Glare › Effect on personnel
- Environmental issues › Physical environment › Object/animal/substance › Tower/antenna (incl guy wires) › Awareness of condition
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land
- Flight time: 1,750 hours in all; 600 in this make and model; 300 in the last 90 days; 200 in the last 30 days; 1,650 as pilot in command
- Last flight review: March 8, 2012
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: sngl
- Injury: fatal
The aircraft
- Airframe total time: 7,000 hours
- Last inspection: 100-hour inspection, April 10, 2013; 120 hours since
- Maximum gross weight: 7,800 lb
- Seats: 1
- Landing gear: fixed
- Engine: Pratt & Whitney PT6A-15AG (turboprop); 500 hours total
- Operator: Terhune Flying Service, Inc
The flight
- Departed from: Perryton TX at 2:55 pm
- Destination: Perryton TX
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 240° at 14 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 91°F (33°C), dew point 57°F (14°C)
- Altimeter: 29.98 inHg
- Observation at 3:35 pm from KPYX, 10 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
22 documents, released by the NTSB on December 20, 2013. 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.
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.