# NTSB CEN18LA270: Air Tractor AT 602, N629LA, Bismarck, IL, July 13, 2018 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: July 13, 2018, 18:15 local (23:15 UTC) - Place: Bismarck, IL - Coordinates: 40.2425, -87.567222 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.2425&lon=-87.5672&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: Air Tractor, FAA FSDO - NTSB case key (mKey): 97794 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN18LA270 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97794/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97794 - Page: https://openairdocs.org/ntsb/CEN18LA270 ## Probable cause A loss of control for reasons that could not be determined based on the available information. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Air Tractor AT-602, 13 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=0390309), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/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 control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Air Tractor AT-602, 16 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=0390309), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) ## Analysis The pilot was conducting an aerial application flight; a witness saw the airplane maneuvering before entering a flat spin. Ground scars at accident site were consistent with a wings- and nose-level impact attitude. Examination of the engine and airframe revealed no evidence of mechanical malfunctions or anomalies. The airplane was not equipped with an elevator down-spring or rudder-aileron interconnect system. According to the manufacturer, these systems were required and improved the stability and handling characteristics of the airplane. Although the circumstances of the accident are consistent with a stall/spin and loss of control, the reason for the loss of control could not be determined based on the available information; and whether the lack of the elevator down-spring and rudder-aileron interconnect systems contributed to the loss of control was not determined. ## Factual narrative On August 13, 2018, about 1815 central daylight time, an Air Tractor 602 airplane, N629LA, was substantially damaged when it was involved in an accident near Bismarck, Illinois. The commercial pilot sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. A witness, who was an agricultural pilot, saw the airplane maneuvering at low altitude over a corn field when it appeared to enter a flat spin. The airplane impacted the ground, and the pilot was taken to the hospital by first responders. The wreckage was found upright in the field. Ground scars at accident site were consistent with a wings- and nose-level impact attitude. Figure 1 shows the airplane location (red) and ground scar location (green) overlaid on a satellite image of the field. The single red dot located to the northwest of the main wreckage denotes the location of the rudder, which was found about 50 feet from the fuselage. Figure 1. Wreckage and Ground Scars at Accident Location The fuselage sustained severe damage to all components forward of the cockpit area. The firewall, main landing gear attachments, and hopper were crushed and segmented by the impact forces. These components remained loosely attached to the fuselage. The aft fuselage showed evidence of crumpling of the structure between the cockpit and the vertical stabilizer. All flight control surfaces were located with the main wreckage and continuity was established from the cockpit area to the control surfaces. The flap actuator was extended about 1 inch, which corresponded to a 7° flap extension. The flap torque tube was continuous to the flap arms on both sides of the fuselage. The airplane was not equipped with an elevator down-spring or rudder-aileron interconnect system. According to the manufacturer, these systems were required and increased the airplane's stability and handling characteristics. The propeller remained attached to the engine and all five of the blades were found in the immediate vicinity of the engine. Two blades were fractured near the blade root and found buried in the soil. The visible blades exhibited chordwise scoring and abrasion of the leading edges, consistent with rotation at the time of impact. ## Aircraft - Registration: [N629LA](https://openairdocs.org/deregistered/N629LA-2021-07-31), registration cancelled 2021-07-31, S/N 6020629, built 2001 (OpenAirDocs) - Reported make and model: Air Tractor AT 602 (No Series) - Registry model: [Air Tractor AT-602](https://openairdocs.org/model/air-tractor-at-602) (registry code 0390309) (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: 6020629 - Year built: 2001 - Airframe hours: 6387 - Engines: Pratt & Whitney PT6A-45R 1100 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Aero Charter Express - Registered owner: Pro-Agr Inc - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, June 29, 2018 - Departed: DNV, Danville, IL - Destination: DNV, Danville, IL - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; injuries: serious; commercial; airplane ratings: single-engine land, multi-engine land; medical: class 2, without waivers/limitations; seat: front; restraint: 5-point; flight hours: 1,026 total, 125 in this make and model, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 63 °F - Altimeter: 29.92 inHg - Observed at: DNV, 3 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 20180713017379A](https://openairdocs.org/incident/20180713017379A), Jul 13, 2018: Air Tractor Inc AT-602, Bismark, IL, Destroyed. On July 13, 2018, at 1815 CT, aircraft registration N629LA, an Air tractor AT-602, impacted the ground about 3 miles northeast of vermilion regional airport… ## Other investigations on N629LA (1) 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. - [NTSB DFW07CA104](https://openairdocs.org/ntsb/DFW07CA104), Apr 30, 2007: Air Tractor AT-602 (N629LA), Benoit, MS, substantial damage. Probable cause: The pilot's failure to maintain clearance with the crops which resulted in a ground loop. A contributing factor was the narrow airstrip ## Docket (8 files) The files NTSB released with the investigation on March 31, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97794. 8.2 MB in all. - Memorandum for the record witness observation summary CEN18LA270 (item 1, PDF, 1 page, 123 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11762417&FileExtension=pdf&FileName=Memorandum%20for%20the%20Record%20Witness%20Observation%20Summary%20CEN18LA270_Redacted-Rel.pdf - Memorandum for the record airframe examination findings CEN18LA270 (item 2, PDF, 3 pages, 298 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11764114&FileExtension=pdf&FileName=Memorandum%20for%20the%20Record%20Airframe%20Examination%20Findings%20CEN18LA270_Redacted-Rel.pdf - AT-602 flight controls schematics CEN18LA270 (item 3, PDF, 10 pages, 6.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11763788&FileExtension=pdf&FileName=AT-602%20Flight%20Controls%20Schematics%20CEN18LA270-Rel.pdf - Memorandum for the record engine examination findings CEN19LA270 (item 4, PDF, 1 page, 122 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11763912&FileExtension=pdf&FileName=Memorandum%20for%20the%20Record%20Engine%20Examination%20Findings%20CEN19LA270_Redacted-Rel.pdf - Police report CEN18LA270 (item 5, PDF, 4 pages, 478 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11763922&FileExtension=pdf&FileName=Police%20Report%20CEN18LA270_Redacted-Rel.pdf - Photo array CEN18LA270 (item 6, PDF, 4 pages, 327 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11763654&FileExtension=pdf&FileName=Photo%20Array%20CEN18LA270-Rel.pdf - Memorandum for the record logbooks pilot information and NTSB form 6120 CEN18LA270 (item 7, PDF, 1 page, 118 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11764766&FileExtension=pdf&FileName=Memorandum%20for%20the%20Record%20Logbooks%20Pilot%20Information%20and%20NTSB%20Form%206120%20CEN18LA270_Redacted-Rel.pdf - Ait tractor party certification form CEN18LA270 (item 8, PDF, 1 page, 151 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11765326&FileExtension=pdf&FileName=Ait%20Tractor%20Party%20Certification%20Form%20CEN18LA270_Redacted-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.