# NTSB CEN22LA389: Air Tractor AT502, N73194, Appleton, MN, August 10, 2022 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: August 10, 2022, 09:30 local (14:30 UTC) - Place: Appleton, MN · Grass drainage berm adjacent to runway. - Coordinates: 45.227502, -96.004529 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.2275&lon=-96.0045&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - 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: Federal Aviation Administration - Minneapolis FSDO - NTSB case key (mKey): 105769 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN22LA389 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105769/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105769 - Page: https://openairdocs.org/ntsb/CEN22LA389 ## Probable cause The pilot’s failure to maintain directional control during the takeoff roll with a quartering tailwind. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [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-502, 8 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=0390303), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Air Tractor AT-502, 6 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=0390303), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Air Tractor AT-502, 2 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=0390303), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Air Tractor AT-502, 4 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=0390303), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Air Tractor AT-502, 9 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=0390303), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Takeoff: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Air Tractor AT-502, 2 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=0390303), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Takeoff: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Air Tractor AT-502, 6 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=0390303), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis The pilot stated that he listened to the airport’s automated weather station broadcast before taxi and, at that time, the surface wind was from 080° at 8 knots. However, while he taxied to runway 13 the airport’s windsock direction was consistent with a surface wind from the north-to-northeast. Before takeoff, he relistened to the airport’s automated weather station broadcast, which still reported the surface wind was from 080° at 8 knots. Believing the automated weather station report was accurate, the pilot continued with a takeoff on runway 13. The pilot stated the takeoff was conducted with 10° of flaps extended but recalled that the takeoff roll was longer than normal. He kept the control stick full aft and to the left (into the wind) during the initial takeoff roll. After the airplane accelerated to 60 mph, he pushed the control stick forward to raise the tail, but the airplane suddenly veered left and off the left side of the runway into a drainage ditch. The pilot was unable to regain directional control with a full right rudder input. During the runway excursion, the right main landing gear separated which resulted in substantial damage to both wings when they impacted the ground. The pilot reported that there were no mechanical failures or anomalies with the airplane that would have prevented normal operation. The pilot believes a left quartering tailwind may have contributed to his loss of directional control during takeoff. He also opined that the surface wind direction reported by the airport’s automated weather station was incorrect, which led him to believe using runway 13 was appropriate for the reported wind direction. A review of the airport’s automated weather station data revealed the reported surface wind direction was 080°-090° in the minutes before and after the accident. A postaccident weather model for the airport included an east-northeast surface wind (061°) at 4.5 knots. Based on the pilot’s windsock observation, the unintentional left veer during the takeoff roll was likely due to the pilot not maintaining directional control with a left quartering tailwind. ## Aircraft - Registration: [N73194](https://openairdocs.org/aircraft/N73194), registered now, S/N 502-0014, built 1988 (OpenAirDocs) - Reported make and model: AIR TRACTOR AT502 - Registry model: [Air Tractor AT-502](https://openairdocs.org/model/air-tractor-at-502) (registry code 0390303) (OpenAirDocs) - Registry engine: [Pratt & Whitney Canada PT6A-60A](https://openairdocs.org/engine/pratt-whitney-canada-pt6a-60a) (registry code 52043, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 502-0014 - Year built: 1988 - Airframe hours: 12354.8 - Engines: Pratt & Whitney Canada PT6A-15AG 680 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Schwenk Aircraft Inc. - Registered owner: Schwenk Aircraft Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, August 7, 2022, 15.6 hours before - Departed: AQP, Appleton, MN - Airport: AQP, Appleton Municipal Airport, runway 13, 3,500 × 75 ft, asphalt - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 68; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review March 26, 2021; seat: single; restraint: 4-point; flight hours: 11,182 total, 2,550 in this make and model, 11,182 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 80° at 8 knots - Visibility: 10 statute miles - Temperature: 73 °F, dew point 63 °F - Altimeter: 30.20 inHg - Observed at: AQP - METAR: KAQP 101433Z AUTO 08008KT 10SM SCT060 SCT090 23/17 A3020 RMK AO2 P0001 ## 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 20220810020929A](https://openairdocs.org/incident/20220810020929A), Aug 10, 2022: Air Tractor Inc AT-502, Appleton, MN, Substantial damage. Aircraft was taking off at aqp (rwy 13) when a gust of wind caused the aircraft to veer to the right and leave the improved (paved) surface of the runway. AWOS… ## Docket (4 files) The files NTSB released with the investigation on March 7, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105769. 5.1 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16738556&FileExtension=pdf&FileName=01%20-%206120_1%20Accident%20Report_Redacted-Rel.pdf - NTSB record of conversation with pilot (item 2, PDF, 2 pages, 96 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16738630&FileExtension=pdf&FileName=02%20-%20NTSB%20Record%20of%20Conversation%20with%20Pilot-Rel.pdf - NTSB weather summary (item 3, PDF, 4 pages, 234 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16738754&FileExtension=pdf&FileName=03%20-%20NTSB%20Weather%20Summary-Rel.pdf - Photos (item 4, PDF, 3 pages, 2 photos, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16738454&FileExtension=pdf&FileName=04%20-%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. --- 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.