# NTSB CEN23LA377: Air Tractor AT-502, N9082C, Great Bend, ND, August 15, 2023

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 3 · Limited · Final report
- Date: August 15, 2023, 10:45 local (15:45 UTC)
- Place: Great Bend, ND
- Coordinates: 46.152, -96.764 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.1520&lon=-96.7640&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Defining event: [Landing: Hard landing](https://openairdocs.org/ntsb-events/092)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 3
- NTSB office: Central Region
- Parties: Transportation Safety Board of Canada, Federal Aviation Administration
- NTSB case key (mKey): 192923
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN23LA377
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192923/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192923
- Page: https://openairdocs.org/ntsb/CEN23LA377

## Probable cause

The pilot’s hard landing on a road and subsequent loss of control, resulting in the airplane impacting a ditch.

## Findings

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

- [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Air Tractor AT-502, 4 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=0390303), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/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)
- [Perception/orientation/illusion: perception](https://openairdocs.org/ntsb-findings/02022040): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Air Tractor AT-502, 1 case](https://openairdocs.org/ntsb-findings/02022040/cases.md?model=0390303), [All aircraft, 61 cases](https://openairdocs.org/ntsb-findings/02022040/cases.md)

## Sequence of events

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

- [Landing: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Air Tractor AT-502, 2 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=0390303), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md)
- [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230); 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)

## Analysis

The pilot reported that he had completed an aerial application with the airplane and was in a turn when the engine lost power. The pilot said he advanced the power lever to full but there was no engine response. The pilot attempted a forced landing on a nearby county road. The airplane landed hard on the road surface, bounced back in the air and floated some distance before settling back on the road. The airplane then veered off the road, went through a ditch, and came to rest in an adjacent farm field. The airplane sustained substantial damage to the left and right tubular clusters where the main landing gear attach. The pilot later reported that, after reviewing speed and altitude data from one of the airplane’s track logs, his recollection of the event did not match what the data showed. He stated that, “The log shows no loss of airspeed that would indicate a loss of power before the initial impact with the ground.” He went on to state that he was no longer confident that his original recollection that there was a power loss was accurate and that this incident was likely caused by pilot error. An examination of the airplane’s fuel control unit (FCU) and fuel pump showed black material in the vicinity of the Py orifice inlet. The manufacturer identified the material as soft debris similar to fluorocarbon and most likely from the packing (O-ring) used on the P3 air inlet fitting. The debris’ size and location did not completely obstruct the inlet and would have allowed for air passage into the FCU, hence not hindering its operability. A bench test of the fuel control unit and fuel pump showed the unit and pump performed normally. No other preaccident failures or malfunctions with the airplane were found that would have precluded normal operations.

## Factual narrative

On August 15, 2023, about 1045 central daylight time, an Air Tractor Inc AT-502, N9082C, was substantially damaged when it was involved in an accident near Great Bend, North Dakota. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 agricultural flight. The pilot reported that he had completed an aerial application with the airplane and was in a turn when the engine lost power. The pilot said he advanced the power lever to full but there was no engine response. The pilot attempted a forced landing on a nearby county road. The airplane landed hard on the road surface, bounced back in the air and floated some distance before settling back on the road. The airplane then veered off the road, went through a ditch, and came to rest in an adjacent farm field. The pilot recalled that he heard the engine noise tone and volume change as the airplane slowed. He also remembered seeing the torque needle reducing to near 500 and falling. He said he didn’t see if it eventually reached zero, but it did not increase as he advanced the power lever. At that point his focus was getting the airplane on the ground safely. In a subsequent statement, the pilot reported that after reviewing speed and altitude data from one of the airplane’s track logs, his recollection of the event didn’t match what the data showed. He stated that, “The log shows no loss of airspeed that would indicate a loss of power before the initial impact with the ground.” He went on to state that he was no longer confident that his original recollection that there was a power loss was accurate. “With this new information it would appear to me that this incident was likely caused by pilot error. It has become evident to me that my memory of the event in that moment are patchy, scrambled, and likely inaccurate.” The airplane sustained damage to the propeller, engine, and the main landing gear. Both fuel tank gauges showed half full of fuel. A postaccident examination of the airplane showed substantial damage to the left and right tubular clusters where the main landing gear attach. The airplane’s fuel control unit (FCU) and fuel pump were retained for further examination. An examination of the FCU showed black material in the vicinity of the Py orifice inlet. The manufacturer identified the material as soft debris similar to fluorocarbon and most likely from the packing (O-ring) used on the P3 air inlet fitting. Per the manufacturer, the debris’ size and location did not completely obstruct the inlet and would have allowed for air passage into the FCU, hence not hindering its operability. A bench test of the fuel control unit and fuel pump showed the unit and pump performed normally. No other preaccident mechanical failures or malfunctions were found with the airplane that would have precluded normal operations.

## Aircraft

- Registration: [N9082C](https://openairdocs.org/aircraft/N9082C), registered now, S/N 502-0193, built 1992 (OpenAirDocs)
- Reported make and model: AIR TRACTOR INC AT-502
- Registry model: [Air Tractor AT-502](https://openairdocs.org/model/air-tractor-at-502) (registry code 0390303) (OpenAirDocs)
- Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52032, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: 502-0193
- Year built: 1992
- Airframe hours: 5062
- Engines: P&W PT6A-34AG 750 horsepower turbo prop
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Dakota Air Spray
- Registered owner: Wilbur-Ellis Air LLC
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, August 9, 2023, 132 hours before
- Departed: BWP, Wahpeton, ND
- Destination: BWP, Wahpeton, ND

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review March 24, 2023; seat: single; restraint: 5-point; flight hours: 1,949 total, 477 in this make and model, 1,940 as pilot in command, 449 in the last 90 days, 200 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 240° at 12 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 75 °F, dew point 63 °F
- Altimeter: 30.05 inHg
- Observed at: KBWP, 8 nm away
- METAR: KBWP 151535Z AUTO 24012KT 10SM CLR 24/17 A3005 RMK AO2

## Docket (9 files)

The files NTSB released with the investigation on May 9, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192923. 7.7 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16430143&FileExtension=pdf&FileName=6120%20---_Redacted-Rel.pdf
- Pilot's statement (item 2, PDF, 1 page, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16853819&FileExtension=pdf&FileName=N9082C%20Accident%20PIC%20Statement-Rel.pdf
- Pilot's supplemental statement (item 3, PDF, 2 pages, 215 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16853799&FileExtension=pdf&FileName=FW_%20N9082C_Redacted-Rel.pdf
- Maintenance logs (item 4, PDF, 2 pages, 3.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16836756&FileExtension=pdf&FileName=Mx%20Logs%20-%20Dec%202022%20-%20CEN23LA377_Redacted-Rel.pdf
- AT-502 fuel system diagram (item 5, PDF, 1 page, 328 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16837289&FileExtension=pdf&FileName=502%20Fuel%20System-Rel.pdf
- Pratt & whitney Canada, fcu and fuel pump exam notes (item 6, PDF, 11 pages, 925 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16836766&FileExtension=pdf&FileName=PWC%20Teardown,%20Jan.%2018,%202024%20A23F0271-Rel.pdf
- P&w Canada e-mails (item 7, PDF, 3 pages, 456 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16853017&FileExtension=pdf&FileName=PWC%20E-mails_Redacted-Rel.pdf
- Photographs (item 8, PDF, 3 pages, 208 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16853809&FileExtension=pdf&FileName=Accident%20Photos%20CEN23LA377-Rel.pdf
- FAA inspector's statement (item 9, PDF, 3 pages, 219 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16965427&FileExtension=pdf&FileName=FW_%20N9082C%20CEN23LA377%20-%20PT6%20power%20loss_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.