# NTSB CEN21LA362: Air Tractor AT-502B, N502CP, Topeka, KS, August 6, 2021

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: August 6, 2021, 08:48 local (13:48 UTC)
- Place: Topeka, KS · Bean field near Topeka, KS
- Coordinates: 39.216972, -95.76119 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.2170&lon=-95.7612&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering-low-alt flying: Fuel exhaustion](https://openairdocs.org/ntsb-events/192)
- 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: Hartzell Propeller, FAA Wichita FSDO, Air Tractor, Pratt & Whitney Canada, Transportation Safety Board of Canada
- NTSB case key (mKey): 103654
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA362
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103654/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103654
- Page: https://openairdocs.org/ntsb/CEN21LA362

## Probable cause

The pilot’s decision to continue low-level aerial application flight maneuvers after the low fuel warning light illuminated, which resulted in a partial loss of engine power due to fuel exhaustion.

## Findings

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

- [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid management (probable cause); cases with it: [Air Tractor AT-502B, 4 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=0390307), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md)
- [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Air Tractor AT-502B, 4 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=0390307), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md)
- [Fuel system](https://openairdocs.org/ntsb-findings/01022800): Aircraft › Aircraft systems · Incorrect use/operation (probable cause); cases with it: [Air Tractor AT-502B, 2 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md?model=0390307), [All aircraft, 181 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md)
- [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Air Tractor AT-502B, 15 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=0390307), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/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: Fuel related](https://openairdocs.org/ntsb-events/190); cases with it: [Air Tractor AT-502B, 1 case](https://openairdocs.org/ntsb-events/190/sequence.md?model=0390307), [All aircraft, 361 cases](https://openairdocs.org/ntsb-events/190/sequence.md)
- [Maneuvering-low-alt flying: Fuel exhaustion](https://openairdocs.org/ntsb-events/192) (defining event); cases with it: [Air Tractor AT-502B, 2 cases](https://openairdocs.org/ntsb-events/192/sequence.md?model=0390307), [All aircraft, 804 cases](https://openairdocs.org/ntsb-events/192/sequence.md)
- [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Air Tractor AT-502B, 7 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=0390307), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md)
- [Maneuvering-low-alt flying: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Air Tractor AT-502B, 5 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=0390307), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md)
- [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Air Tractor AT-502B, 14 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=0390307), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)
- [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [Air Tractor AT-502B, 8 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=0390307), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md)

## Analysis

The commercial pilot reported that before the aerial application flight, he added Jet A fuel to both wing tanks for a total of 150 gallons of fuel onboard. While flying low-level over a field on the third load, the pilot noticed a change in engine power. He maneuvered the airplane out of the field and the engine steadily lost power. The pilot tried to advance the power forward with no change and the airspeed and altitude decreased. The pilot performed a forced landing to a bean field. During the landing, the airplane bounced, slid across a road, and then came to rest upright. The airplane sustained substantial damage to the fuselage and the right wing. The property owner of the bean field reported that he helped the pilot add about 9 gallons of red die automotive diesel fuel to the left fuel tank and about 5 gallons of the fuel to the right fuel tank after the accident. The pilot reported that the low fuel warning light illuminated about five minutes before the partial loss of engine power, yet the pilot continued with the low-level aerial application maneuvers. When the low fuel warning light illuminates, the airplane flight manual states to, “fly straight and level and monitor fuel gauges” and “land as soon as practical.” The operator reported that there were no preimpact mechanical malfunctions or failures with the airframe and engine that would have precluded normal operation.

## Aircraft

- Registration: [N502CP](https://openairdocs.org/aircraft/N502CP), registered now, S/N 502B2632, built 2008 (OpenAirDocs)
- Reported make and model: AIR TRACTOR INC AT-502B
- Registry model: [Air Tractor AT-502B](https://openairdocs.org/model/air-tractor-at-502b) (registry code 0390307) (OpenAirDocs)
- Registry engine: [Pratt & Whitney Canada PT6A-34AG](https://openairdocs.org/engine/pratt-whitney-canada-pt6a-34ag) (registry code 52251, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: 502B2632
- Year built: 2008
- Airframe hours: 4648.1
- Engines: Pratt & Whitney Canada PT6A-34AG 750 horsepower turbo prop
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: McElwain Sprayers, LLC, doing business as McElwain Sprayers, LLC
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, June 1, 2021
- Departed: K59, Atchison, KS
- Destination: 69K, Wamego, KS
- Equipment: Stall warning system, ADS-B

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 25; injuries: none; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review June 5, 2021; seat: single; restraint: 4-point; flight hours: 2,470.7 total, 473 in this make and model, 2,452.9 as pilot in command, 563.3 in the last 90 days, 314.2 in the last 30 days, 11.5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 80° at 5 knots
- Visibility: 9 statute miles
- Lowest ceiling: none
- Temperature: 72 °F, dew point 64 °F
- Altimeter: 30.03 inHg
- Observed at: KTOP, 11 nm away
- METAR: KTOP 061353Z 08005KT 9SM CLR 22/18 A3003 RMK AO2 SLP159 T02220178

## 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 20210806011439A](https://openairdocs.org/incident/20210806011439A), Aug 6, 2021: Air Tractor Inc AT-502B, Hoyt, KS, Substantial damage. The pilot/aircraft departed K59 and was in the process of aerial Application of chemicals to a field when the fuel low light illuminated. 10 minutes later the…

## Docket (5 files)

The files NTSB released with the investigation on September 15, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103654. 88.5 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 8 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12612411&FileExtension=pdf&FileName=NTBS%20Form%206120_1%20Redacted-Rel.pdf
- Accident photographs (item 2, PDF, 13 pages, 4.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12609736&FileExtension=pdf&FileName=Accident%20Photographs-Rel.pdf
- Various statements (item 3, PDF, 12 pages, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12637796&FileExtension=pdf&FileName=Various%20Statements%20Redacted-Rel.pdf
- Airframe manufacturer and airworthiness documents (item 4, PDF, 20 pages, 76.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12613215&FileExtension=pdf&FileName=Airframe%20Manufacturer%20and%20Airworthiness%20Documents%20Redacted-Rel.pdf
- NTSB party member forms (item 5, PDF, 2 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12609434&FileExtension=pdf&FileName=NTSB%20Party%20Member%20Forms%20Redacted-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.

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