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WPR11LA272 · Air Tractor Inc AT-301

21 Jun 2011 · Hogeland, MT, United States

Air Tractor Inc AT-301 · Accident while maneuvering

From Harlem Airport (48S) to Harlem Airport (48S)

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Event

NTSB case
WPR11LA272
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
1 · all aircraft and ground
Ground fatalities
Unknown
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Air Tractor Inc AT-301

Aircraft type
Air Tractor AT-301
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N3661B
Operator
Unknown
Onboard fatalities
Unknown
Route
From Harlem Airport (48S), Harlem, MTTo Harlem Airport (48S), Harlem, MT
Aircraft age
About 30 years (built 1981)
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 137: Agricultural
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
Maneuvering · low-altitude flying
Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Unknown or undetermined
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Not determined › Not determined

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

The pilot departed in the agricultural airplane shortly before sunrise to apply herbicide in a field about 18 miles from the departure airport. Witnesses located adjacent to the accident site next to the field to be sprayed heard the airplane approach, turn, and collide with the ground.

The airplane was loaded with fuel and herbicide, such that it was about 9 percent (565 pounds) over its maximum gross weight. No anomalies were noted with the engine or airframe that would have precluded normal operation, and propeller damage signatures indicated the engine was producing power at the time of impact. The flaps were in the fully extended position, contrary to the airplane manufacturer's recommendations for this phase of flight.

The airplane sustained high-energy impact damage consistent with a steep nose-down descent into the ground, possibly due to a stall-spin. The increased airplane load would have reduced the stall speed, and the use of full flaps would also have affected the airplane's handling characteristics during the turn; however, the investigation could not determine to what extent this played a role in the accident. The reason for the use of full flaps could not be determined.

Family members reported that the pilot was both under financial, work, and personal stress. One of his daughters reported that during a telephone conversation the week before the accident, the pilot sounded tired and in a state of malaise; during the conversation the pilot sounded "dis-jointed and out of character," and he stated that he was "getting tired of flying."

Toxicological testing revealed that the pilot was taking medication used for the symptomatic relief of depressive illness. While the dose in itself was not high enough to pose a hazard to flight, he did not declare either his use of it or the underlying condition on his most recent FAA medical certificate application 1 month before the accident. However, it could not be determined whether the underlying condition for which the pilot was being treated would have affected is flying ability.

Probable cause

Collision with the ground while maneuvering at low altitude for reasons that could not be determined because postaccident examination did not reveal any anomalies that would have precluded normal operation.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record WPR11LA272
Event ID
20110621X20906
Case number
WPR11LA272
Dataset
full-current
Source SHA-256
5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: 4065ba5b29a2e9b44cd74f53cfaf4691dc3d645a077cc3ca8d2ea9945f50806b; retrieved 2026-09-13T21:28:35.809Z.