# NTSB CEN24LA241: Air Tractor AT-301, N3165C, Andover, MO, June 27, 2024

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: June 27, 2024, 10:40 local (15:40 UTC)
- Place: Andover, MO · crop field
- Coordinates: 40.567486, -93.911747
- Nearby events: https://openairdocs.org/map.md?lat=40.5675&lon=-93.9117&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute-cruise: Fuel related](https://openairdocs.org/ntsb-events/190)
- 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 - Kansas City FSDO
- NTSB case key (mKey): 194561
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN24LA241
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194561/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=194561
- Page: https://openairdocs.org/ntsb/CEN24LA241

## Probable cause

The pilot’s inability to maintain altitude and airspeed during cruise flight likely due to a decrease in engine performance associated with the unauthorized use of automobile fuel, which led to an inflight collision with a tree and hard landing.

## Findings

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

- [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Air Tractor AT-301, 6 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=0390103), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md)
- [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Air Tractor AT-301, 5 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=0390103), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md)
- [Performance/control parameters: powerplant parameters](https://openairdocs.org/ntsb-findings/01062050): Aircraft › Aircraft oper/perf/capability · Related operating info (probable cause); cases with it: [Air Tractor AT-301, 1 case](https://openairdocs.org/ntsb-findings/01062050/cases.md?model=0390103), [All aircraft, 81 cases](https://openairdocs.org/ntsb-findings/01062050/cases.md)
- [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid type (probable cause); cases with it: [Air Tractor AT-301, 7 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=0390103), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md)
- [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Incorrect use/operation (probable cause); cases with it: [Air Tractor AT-301, 7 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=0390103), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md)
- [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Related operating info (probable cause); cases with it: [Air Tractor AT-301, 7 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=0390103), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md)
- [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Air Tractor AT-301, 6 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=0390103), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md)

## Sequence of events

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

- [Enroute-cruise: Fuel related](https://openairdocs.org/ntsb-events/190) (defining event); cases with it: [Air Tractor AT-301, 2 cases](https://openairdocs.org/ntsb-events/190/sequence.md?model=0390103), [All aircraft, 361 cases](https://openairdocs.org/ntsb-events/190/sequence.md)
- [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Air Tractor AT-301, 19 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=0390103), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)
- [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Air Tractor AT-301, 25 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=0390103), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)
- [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Air Tractor AT-301, 2 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=0390103), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md)

## Analysis

The pilot was conducting an agricultural flight when the airplane was unable to maintain altitude and airspeed during cruise flight between the departure airport and the field to be fertilized. The pilot reported that the engine continued to operate normally, and all the engine instruments (engine RPM, manifold pressure, oil pressure, fuel pressure, and oil temperature) indicated normal values for the airplane in a cruise flight configuration with the flaps retracted. The pilot verified that the mixture and throttle positions were correct before she increased the throttle, but there was no increase in engine power and the airplane continued to descend. The pilot began to jettison the 1,700 lbs of dry fertilizer as she maneuvered the airplane toward a nearby open field. The airplane’s left wing clipped a tree as the airplane descended into the field. The airplane subsequently landed hard and came to rest upright in the field. The fuselage, engine mounts, and both wings were substantially damaged during the hard landing. The airplane’s wing fuel tanks remained intact and contained ample fuel that exhibited the color and odor of automobile fuel. A review of airworthiness documentation revealed that the airplane was not authorized to use automobile fuel. When interviewed, the airplane owner/operator acknowledged that the airplane did not have a supplemental type certificate (STC) to use the 87-octane automobile fuel that he sourced from a local gas station. According to a company that specializes in issuance of automobile fuel STCs, the use of automobile fuel containing ethanol can result in damage to rubber and aluminum fuel system components, increases the volatility of the fuel, and can absorb significant amounts of water. Carburetor icing can develop faster with higher volatility fuels. Additionally, older engine designs like the airplane’s Pratt & Whitney R-1340-59 radial engine, are suspectable to valve seat recession if the fuel used contains an insufficient level of lead. When asked, the airplane operator indicated that he did not check the automobile gas for the presence of ethanol, nor did he blend aviation fuel to increase the lead content of the automobile fuel. The airplane’s radial engine separated from the fuselage during the accident and was not examined during the investigation.

## Aircraft

- Registration: [N3165C](https://openairdocs.org/aircraft/N3165C), registered now, S/N 301-0545, built 1984 (OpenAirDocs)
- Reported make and model: Air Tractor Inc AT-301
- Registry model: [Air Tractor AT-301](https://openairdocs.org/model/air-tractor-at-301) (registry code 0390103) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 301-0545
- Year built: 1984
- Airframe hours: 8049
- Engines: Pratt & Whitney R-1340-59 650 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, March 16, 2024
- Departed: LWD, Lamoni, IA
- Equipment: Stall warning system

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 23; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; last flight review June 8, 2023; seat: single; restraint: 4-point; flight hours: 919 total, 67 in this make and model, 830 as pilot in command, 56 in the last 90 days, 51 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 140° at 6 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 75 °F, dew point 63 °F
- Altimeter: 29.99 inHg
- Observed at: LWD, 4 nm away
- METAR: METAR KLWD 271553Z AUTO 14006KT 10SM CLR 24/17 A2999 RMK AO2 SLP146 T02390167=

## 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 20240627010549A](https://openairdocs.org/incident/20240627010549A), Jun 27, 2024: Air Tractor Inc AT-301, Andover, MO, Substantial damage. The aircraft departed with full fuel and 1700 lbs of granulated fertilizer. Approximately three miles from the departure airport, the pilot noticed a steady…

## Docket (8 files)

The files NTSB released with the investigation on January 21, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=194561. 11.0 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=18147414&FileExtension=pdf&FileName=01%20-%20NTSB%206120_1_Redacted-Rel.pdf
- Pilot statement (item 2, PDF, 1 page, 770 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18148103&FileExtension=pdf&FileName=02%20-%20Pilot%20Statement_Redacted-Rel.pdf
- FAA record of conversation with pilot (item 3, PDF, 2 pages, 138 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18148002&FileExtension=pdf&FileName=03%20-%20FAA%20Record%20of%20Conversation%20with%20Pilot_Redacted-Rel.pdf
- FAA record of visit with airplane owner and operator (item 4, PDF, 2 pages, 141 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18147200&FileExtension=pdf&FileName=04%20-%20FAA%20Record%20of%20Visit%20with%20Airplane%20Owner%20and%20Operator_Redacted-Rel.pdf
- Maintenance logbooks (excerpts) (item 5, PDF, 5 pages, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18148345&FileExtension=pdf&FileName=05%20-%20Maintenance%20Logbooks%20(Excerpts)_Redacted-Rel.pdf
- Petersen aviation autogas STC (website excerpts) (item 6, PDF, 7 pages, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18148113&FileExtension=pdf&FileName=06%20-%20Petersen%20Aviation%20STC%20for%20Autogas%20(Website%20Excerpts)_Redacted-Rel.pdf
- Meteorological data (item 7, PDF, 3 pages, 194 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18147776&FileExtension=pdf&FileName=07%20-%20Meteorological%20Data-Rel.pdf
- Investigation photographs (item 8, PDF, 4 pages, 3 photos, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18148206&FileExtension=pdf&FileName=08%20-%20Investigation%20Photographs-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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