# NTSB CEN09CA535: Air Tractor AT-301, N73102, Leland, IL, August 17, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 17, 2009, 18:00 local (23:00 UTC) - Place: Leland, IL - Coordinates: 41.665832, -88.771385 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.6658&lon=-88.7714&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 15, 2009 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA-DuPage FSDO - NTSB case key (mKey): 74563 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN09CA535 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74563/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74563 - Page: https://openairdocs.org/ntsb/CEN09CA535 ## Probable cause A total loss of engine power in flight due to a loss of engine oil as a result of the separation of the propeller hub components for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Propeller system: propeller hub section](https://openairdocs.org/ntsb-findings/01046114): Aircraft › Aircraft propeller/rotor · Failure (probable cause); cases with it: [Air Tractor AT-301, 1 case](https://openairdocs.org/ntsb-findings/01046114/cases.md?model=0390103), [All aircraft, 13 cases](https://openairdocs.org/ntsb-findings/01046114/cases.md) - [Propeller system: propeller hub section](https://openairdocs.org/ntsb-findings/01046114): Aircraft › Aircraft propeller/rotor · Not specified (probable cause); cases with it: [Air Tractor AT-301, 1 case](https://openairdocs.org/ntsb-findings/01046114/cases.md?model=0390103), [All aircraft, 13 cases](https://openairdocs.org/ntsb-findings/01046114/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: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Air Tractor AT-301, 3 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=0390103), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Maneuvering-low-alt flying: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340); cases with it: [Air Tractor AT-301, 5 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=0390103), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Emergency descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Air Tractor AT-301, 17 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=0390103), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: 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) ## Analysis The pilot reported that he was spraying a field when “oil started hitting [his] windshield” and the engine lost oil pressure. Shortly thereafter, the engine “clattered and then quit.” He executed a forced landing into a corn field, where the airplane sustained substantial damage to the left wing. The pilot noted that there was no indication of a problem prior to the loss of engine oil. A postaccident inspection revealed oil spray residue on the engine cowling and windshield. Examination determined that the spring puller bolt assembly and the piston gasket nut had separated from the propeller hub. The components were not recovered, precluding further examination. As a result, the exact nature of the failure could not be determined. ## Factual narrative The pilot reported that he was spraying a field when “oil started hitting [his] windshield” and the engine lost oil pressure. Shortly thereafter, the engine “clattered and then quit.” He executed a forced landing into a corn field. The airplane sustained substantial damage to the left wing. The pilot noted that there was no indication of a problem prior to the loss of engine oil. A post accident inspection revealed oil spray residue on the engine cowling and windshield. Examination determined that the spring puller bolt assembly and the piston gasket nut had separated from the propeller hub. The components were not recovered precluding further examination. As a result, the exact nature of the failure could not be determined. ## Aircraft - Registration: [N73102](https://openairdocs.org/deregistered/N73102-2017-04-04), registration cancelled 2017-04-04, S/N 301-0656, built 1986 (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: 301-0656 - Airframe hours: 8042 - Engines: P&W R1340 SERIES 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Hendrickson Flying Service Inc - Registered owner: Hendrickson Flying Service Inc - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, July 8, 2009 - Departed: IL93, Creston, IL - Destination: IL93, Creston, IL - Flight plan: Unknown - Airport: IL93, Hendrickson Flying Service ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 69; injuries: none; flight instructor, flight engineer, commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; seat: single; flight hours: 12,905 total, 466 in this make and model, 12,231 as pilot in command, 105 in the last 90 days, 105 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 70 °F - Altimeter: 29.96 inHg - Observed at: ARR, 18 nm away ## Docket (4 files) The files NTSB released with the investigation on October 1, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74563. 1.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 780 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40319367&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot Statement (item 2, .PDF, 56 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40319368&FileExtension=.PDF&FileName=Pilot%20Statement-Master.PDF - Maintenance Records (item 3, .PDF, 183 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40319371&FileExtension=.PDF&FileName=Maintenance%20Records-Redacted.PDF - Propeller Assembly Diagram (item 4, .PDF, 242 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40319370&FileExtension=.PDF&FileName=Propeller%20Assembly%20Diagram-Master.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.