# NTSB CEN20LA234: Air Tractor AT402, N1532H, Pine Bluff, AR, June 17, 2020 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: June 17, 2020, 18:00 local (23:00 UTC) - Place: Pine Bluff, AR - Coordinates: 34.206665, -91.873886 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.2067&lon=-91.8739&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA FSDO - NTSB case key (mKey): 101453 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN20LA234 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101453/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101453 - Page: https://openairdocs.org/ntsb/CEN20LA234 ## Probable cause The pilot’s exceedance of the airplane’s critical angle of attack, which led to an aerodynamic stall and a loss of airplane control. Contributing was a partial loss of engine power for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Air Tractor AT-402, 3 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=0390205), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Aircraft](https://openairdocs.org/ntsb-findings/01050000): Aircraft › Aircraft power plant · Unknown/Not determined (probable cause); cases with it: [Air Tractor AT-402, 2 cases](https://openairdocs.org/ntsb-findings/01050000/cases.md?model=0390205), [All aircraft, 151 cases](https://openairdocs.org/ntsb-findings/01050000/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-402, 4 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=0390205), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/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: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Air Tractor AT-402, 2 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=0390205), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Air Tractor AT-402, 5 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=0390205), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Maneuvering-low-alt flying: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [Air Tractor AT-402, 3 cases](https://openairdocs.org/ntsb-events/241/sequence.md?model=0390205), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) ## Analysis The pilot reported that, during an aerial application flight, a partial loss of engine power occurred while he was performing the first climbing turn to reverse course. The airplane subsequently descended and impacted terrain in a near vertical attitude. Postaccident examination of the engine and its components revealed no preimpact anomalies. The reason for the partial loss of engine power could not be determined with the available evidence for this accident investigation. Given the airplane’s near-vertical descent, it is likely that the pilot exceeded the airplane’s critical angle of attack during the climbing turn, which resulted in an aerodynamic stall and a loss of airplane control from which the pilot was unable to recover. ## Factual narrative On June 17, 2020, about 1800 central daylight time, an Air Tractor AT-402 airplane, N1532H, was substantially damaged when it was involved in an accident near Pine Bluff, Arkansas. The pilot was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. The pilot reported that he was spraying applicant over a field and that a partial loss of engine power occurred when he began the first climbing turn to reverse course and make a second pass. The airplane subsequently descended and impacted terrain in a near-vertical attitude. The pilot also reported that the airplane owner had previously told him that the engine could potentially have 15% less power and had a history of engine problems. Maintenance log entries did not show a history of engine problems. Postaccident examination of the engine and its components discovered multiple signatures of rotational scoring and rubbing. The fuel control unit, fuel pump, starting flow control unit, overspeed governor, and propeller governor showed no preimpact anomalies but did show signs of contamination consistent with the presence of agricultural fertilizer. The engine case and components were damaged by impact. ## Aircraft - Registration: [N1532H](https://openairdocs.org/deregistered/N1532H-2022-07-30), registration cancelled 2022-07-30, S/N 402-0852 (OpenAirDocs) - Reported make and model: AIR TRACTOR AT402 - Registry model: [Air Tractor AT-402](https://openairdocs.org/model/air-tractor-at-402) (registry code 0390205) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52034, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 402-0852 - Year built: 2019 - Engines: Pratt & Whitney Canada PT6A-28 turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Farm Brothers Flyers A LLC - Registered owner: Farm Brothers Flyers A LLC - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, March 19, 2020 - Departed: PBF, Pine Bluff, AR - Destination: PBF, Pine Bluff, AR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 21; injuries: serious; commercial; airplane ratings: single-engine land; medical: class 2, unknown; seat: single ## Weather - Conditions: Visual (VMC), Day - Wind: 60° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 57 °F - Altimeter: 30.02 inHg - Observed at: KPBF, 4 nm away ## 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 20200617011219A](https://openairdocs.org/incident/20200617011219A), Jun 17, 2020: Air Tractor Inc AT-402, Pine Bluff, AR, Destroyed. On July 17, 2020 at apprx 1800 hrs local an AT-402, N1532H, sn 402-0852 was conducting aerial application operations dispensing urea at a field apprx 6 miles… ## Docket (5 files) The files NTSB released with the investigation on July 26, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101453. 9.3 MB in all. - Record of conversation, pilot (item 1, PDF, 1 page, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15723254&FileExtension=pdf&FileName=ROC%20Pilot%20CEN20LA234-Rel.pdf - Photos (item 2, PDF, 2 pages, 2 photos, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15723603&FileExtension=pdf&FileName=Photos%202%20CEN20LA234-Rel.pdf - Memorandum of engine and components examination summary (item 3, PDF, 1 page, 72 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15744825&FileExtension=pdf&FileName=Memorandum%20of%20Examination-Rel.pdf - Maintenance logbooks (item 4, PDF, 5 pages, 6.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15588027&FileExtension=pdf&FileName=Logs_Redacted-Rel.pdf - Lab report summary (item 5, PDF, 1 page, 106 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15589413&FileExtension=pdf&FileName=Lab%20report%20summary-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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.