# NTSB CEN21LA393: Air Tractor AT-401B, N5081W, Storm Lake, IA, September 1, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: September 1, 2021, 08:32 local (13:32 UTC) - Place: Storm Lake, IA - Coordinates: 42.643, -95.2019 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.6430&lon=-95.2019&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: 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, Des Moines FSDO - NTSB case key (mKey): 103787 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA393 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103787/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103787 - Page: https://openairdocs.org/ntsb/CEN21LA393 ## Probable cause The pilot’s failure to maintain adequate airspeed during a landing approach with a tailwind that resulted in a landing overrun and impact with terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: incorrect action selection](https://openairdocs.org/ntsb-findings/02041010): Personnel issues › Action/decision · Flight crew; cases with it: [Air Tractor AT-401B, 1 case](https://openairdocs.org/ntsb-findings/02041010/cases.md?model=0390207), [All aircraft, 397 cases](https://openairdocs.org/ntsb-findings/02041010/cases.md) - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Air Tractor AT-401B, 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=0390207), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/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-401B, 3 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=0390207), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [Air Tractor AT-401B, 1 case](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=0390207), [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. - [Landing: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Air Tractor AT-401B, 1 case](https://openairdocs.org/ntsb-events/400/sequence.md?model=0390207), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Air Tractor AT-401B, 3 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=0390207), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Air Tractor AT-401B, 1 case](https://openairdocs.org/ntsb-events/060/sequence.md?model=0390207), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Air Tractor AT-401B, 1 case](https://openairdocs.org/ntsb-events/096/sequence.md?model=0390207), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Air Tractor AT-401B, 3 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=0390207), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The commercial pilot reported that he was attempting to land on dew-covered grass runway following an aerial application flight when the airplane overran the runway and nosed over coming to rest inverted. The airplane sustained substantial damage to the rudder and horizontal stabilizer. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. At the time of the accident the airplane was landing on runway 31 with wind 110o at 4 knots. The pilot reported that the accident was the result of the airplane being too fast during the final approach with a tailwind and the dew-covered runway. ## Aircraft - Registration: [N5081W](https://openairdocs.org/aircraft/N5081W), registered now, S/N 401B-1013, built 1996 (OpenAirDocs) - Reported make and model: AIR TRACTOR INC AT-401B - Registry model: [Air Tractor AT-401B](https://openairdocs.org/model/air-tractor-at-401b) (registry code 0390207) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 401B-1013 - Year built: 1996 - Airframe hours: 3547.6 - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Barts Flying Service Inc - Registered owner: Barts Flying Service Inc - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, May 6, 2021 - Destination: Same as departure - Airport: SLB, Storm Lake Municipal Airport, runway 31, 2,000 × 150 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: none; commercial, private; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; last flight review September 16, 2012; seat: center; restraint: 4-point; flight hours: 1,207 total, 143 in this make and model, 1,156 as pilot in command, 263 in the last 90 days, 85 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 120° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 64 °F, dew point 59 °F - Altimeter: 30.01 inHg - Observed at: SLB ## 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 20210901011429A](https://openairdocs.org/incident/20210901011429A), Sep 1, 2021: Air Tractor Inc AT-401B, Storm Lake, IA, Substantial damage. Pilot stated that the grass runway which runs parallel to runway 31 was wet with dew and the braking action was poor. Pilot stated that he left the flaps at… ## Docket (2 files) The files NTSB released with the investigation on March 7, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103787. 3.0 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 12 pages, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13274253&FileExtension=pdf&FileName=NTSB%20Form%206120.1%20N5081W_Redacted-Rel.pdf - Photo log (item 2, PDF, 2 pages, 106 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13277920&FileExtension=pdf&FileName=Photo%20Log-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.