Air Tractor INC AT-502 accident near Firebaugh, California, September 22, 2012
On September 22, 2012, a 1991 Air Tractor INC AT-502, registered N4556S, was substantially damaged in an accident during initial climb near Firebaugh, California. 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 decision to continue the takeoff after the engine stopped producing its full-rated torque while operating in high-density altitude conditions and his subsequent failure to maintain clearance from the power transmission wires.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 22, 2012
- Place
- Firebaugh, California · 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-502, built 1991 · all AT-502s on the register
- Registration
- N4556S · no longer on the register · serial 502-0137
- 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 ferried the airplane to a private ag-operating airstrip where it was fully fueled, and 400 gallons of defoliant were loaded in the hopper. During the takeoff roll for the aerial application flight, the pilot noticed that the engine was not producing its full-rated torque, but he chose not to abort the takeoff. The pilot reported that, when the airplane reached the end of the runway, it lifted off but would not climb out of ground effect. As the airplane approached power transmission wires about 0.5 mile from the airstrip, the pilot began dumping the defoliant load to gain altitude. Dumping the load resulted in the airplane gaining some altitude, but, simultaneously, the airplane's nose pitched up, which increased drag and stopped the climb. The airplane struck the wires and landed hard in an open field. Postaccident examination of the engine found no preimpact mechanical anomalies that would have precluded normal engine operation. It is likely that the engine was not producing its full-rated torque because the density altitude was 2,400 feet (as compared to the field elevation of 236 feet), which reduced the available engine torque.
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
- Miscellaneous/other during initial climb defining event
- Controlled flight into terrain or object (CFIT) during initial climb
The NTSB's findings
- cause Personnel issues › Action/decision › Action › Lack of action › Pilot
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Altitude › Not attained/maintained
- cause Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Pilot
- cause Environmental issues › Conditions/weather/phenomena › Temp/humidity/pressure › High density altitude › Effect on operation
Pilot
- Certificate: airline transport pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 10,608 hours in all; 819 in this make and model; 147 in the last 90 days; 31 in the last 30 days
- Last flight review: March 25, 2012
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 10,147 hours
- Last inspection: 100-hour inspection, August 8, 2012
- Seats: 1
- Landing gear: fixed
- Engine: P&W PT6A SER (turboprop); 0 hours total
- Operator: Thiel Air Care INC
The flight
- Departed from: Firebaugh CA at 2:00 am
- Destination: Firebaugh CA
- Flight plan: not recorded
- Runway 09, 2,300 ft by 35 ft
Weather at the time
- Light: daylight
- Wind: from 290° at 7 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 90°F (32°C), dew point 45°F (7°C)
- Altimeter: 29.85 inHg
- Observation at 11:53 pm from MAE, 28 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.
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.