# NTSB CEN23LA336: Air Tractor AT-402B, N402PR, Alta, IA, July 29, 2023

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: July 29, 2023, 07:30 local (12:30 UTC)
- Place: Alta, IA
- Coordinates: 42.675, -95.3042 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.6750&lon=-95.3042&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Central Region
- Parties: FAA FSDO
- NTSB case key (mKey): 192749
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN23LA336
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192749/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192749
- Page: https://openairdocs.org/ntsb/CEN23LA336

## Probable cause

The airplane’s encounter with a dust devil, which resulted in a loss of lift, and subsequent collision with powerlines.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Air Tractor AT-402B, 7 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=0390208), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Air Tractor AT-402B, 7 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=0390208), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Wind: dust devil/whirlwind](https://openairdocs.org/ntsb-findings/03034060): Environmental issues › Conditions/weather/phenomena · Ability to respond/compensate (probable cause); cases with it: [Air Tractor AT-402B, 1 case](https://openairdocs.org/ntsb-findings/03034060/cases.md?model=0390208), [All aircraft, 38 cases](https://openairdocs.org/ntsb-findings/03034060/cases.md)
- [Wind: dust devil/whirlwind](https://openairdocs.org/ntsb-findings/03034060): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [Air Tractor AT-402B, 1 case](https://openairdocs.org/ntsb-findings/03034060/cases.md?model=0390208), [All aircraft, 38 cases](https://openairdocs.org/ntsb-findings/03034060/cases.md)
- [Wind: dust devil/whirlwind](https://openairdocs.org/ntsb-findings/03034060): Environmental issues › Conditions/weather/phenomena · Contributed to outcome (probable cause); cases with it: [Air Tractor AT-402B, 1 case](https://openairdocs.org/ntsb-findings/03034060/cases.md?model=0390208), [All aircraft, 38 cases](https://openairdocs.org/ntsb-findings/03034060/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Maneuvering-low-alt flying: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Air Tractor AT-402B, 3 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=0390208), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md)
- [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470) (defining event); cases with it: [Air Tractor AT-402B, 13 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=0390208), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)
- [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Air Tractor AT-402B, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=0390208), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)

## Analysis

The pilot reported that he was completing an aerial application flight over a cultivated field. During the fourth pass, the airplane encountered a dust devil (also called a whirlwind), lost lift and impacted powerlines. Upon impact with the powerlines the rudder separated from the airplane and the airplane began a left turn. Unable to arrest the turn, the pilot reduced power and made a forced landing to the field that he was spraying. Upon touch down the left main landing gear separated from the fuselage and the airplane slid to a stop. The airplane sustained substantial damage to the left wing, vertical stabilizer and rudder. The operator reported there were no preimpact mechanical malfunctions or failures with the airframe or the engine that would have precluded normal operation. A review of the Federal Aviation Administration Aviation (FAA) Weather Handbook (FAA-H-8083-28) and the FAA Aeronautical Information Manual found no detailed information listed about dust devils or the potential hazards of flying through dust devils.

## Aircraft

- Registration: [N402PR](https://openairdocs.org/aircraft/N402PR), registered now, S/N 402B-1282, built 2013 (OpenAirDocs)
- Reported make and model: AIR TRACTOR INC AT-402B
- Registry model: [Air Tractor AT-402B](https://openairdocs.org/model/air-tractor-at-402b) (registry code 0390208) (OpenAirDocs)
- Registry engine: [Pratt & Whitney Canada PT6A-15AG](https://openairdocs.org/engine/pratt-whitney-canada-pt6a-15ag) (registry code 52246, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: 402B-1282
- Year built: 2013
- Airframe hours: 1679
- Engines: Pratt & Whitney Canada PT6A-15HE 650 horsepower turbo prop
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Barts Flying Service Inc, doing business as Barts Flying Service Inc
- Registered owner: Barts Flying Service Inc
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, June 15, 2023

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 52; injuries: none; flight instructor, commercial, private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, waiver time limited special; last flight review October 24, 2022; seat: center; restraint: 3-point; flight hours: 6,600 total, 1,500 in this make and model, 6,550 as pilot in command, 60 in the last 90 days, 40 in the last 30 days, 8 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 20° at 8 knots
- Visibility: 9 statute miles
- Lowest ceiling: none
- Temperature: 66 °F, dew point 64 °F
- Altimeter: 30.16 inHg
- Observed at: KSLB, 5 nm away
- METAR: KSLB 291235Z AUTO 02008KT 9SM CLR 19/18

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20230729008049A](https://openairdocs.org/incident/20230729008049A), Jul 29, 2023: Air Tractor Inc AT-402B, Alta, IA, Substantial damage. An Air tractor AT-402, clipped some power lines, during aerial application, and came down in a bean field near Alta, IA. POB: 1, no injuries. The aircraft was…

## Docket (2 files)

The files NTSB released with the investigation on November 16, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192749. 2.3 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 612 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16319799&FileExtension=pdf&FileName=6120_1%20NTSB_Redacted-Rel.pdf
- Photos (item 2, PDF, 3 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16319673&FileExtension=pdf&FileName=Accident%20Photos-Rel.pdf

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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