# NTSB CEN14LA287: Air Tractor AT 301, N8593S, Pearsall, TX, June 12, 2014 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 12, 2014, 12:00 local (17:00 UTC) - Place: Pearsall, TX - Coordinates: 28.879985, -99.089492 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=28.8800&lon=-99.0895&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 22, 2015 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 89431 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN14LA287 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/89431/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=89431 - Page: https://openairdocs.org/ntsb/CEN14LA287 ## Probable cause The failure of the No. 1 cylinder rod at the link pin. Contributing to the accident was oil starvation to the rod bearing due to the improper flushing of the oil cooler, which allowed metal and other debris in the oil to clog the drain and the led to the piston’s failure. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Air Tractor AT-301, 6 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=0390103), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Terrain](https://openairdocs.org/ntsb-findings/03021000): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Air Tractor AT-301, 2 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md?model=0390103), [All aircraft, 267 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md) - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Air Tractor AT-301, 6 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=0390103), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Fluids: oil](https://openairdocs.org/ntsb-findings/01071020): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Air Tractor AT-301, 1 case](https://openairdocs.org/ntsb-findings/01071020/cases.md?model=0390103), [All aircraft, 174 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Air Tractor AT-301, 9 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=0390103), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/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) - [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) ## Analysis The pilot reported that, while returning to the airport after spraying a cornfield, he noticed that the engine cylinder head temperature was high. After landing, he checked the engine cylinders for discrepancies and found none, so he decided to continue the spraying operations at the cornfield. As the pilot pulled up the airplane from a spray run, the engine started to vibrate and lose power. He subsequently made a forced landing in a nearby field, which resulted in the airplane sustaining substantial damage to both wings. During postaccident examination, a considerable amount of metal was found in the oil drain. The No. 2 cylinder front spark plug was loose. After removing all of the spark plugs, an attempt was made to rotate the engine, but it seized. After removing the No. 1 cylinder, it was discovered that the piston rod had broken at the link pin; no other rods were broken. The No. 1 cylinder link pin was scored, and there was evidence of oil starvation at the rod bearing. According to the operator, the engine had accrued about 100 hours since it had received extensive maintenance, including the replacement of the crankshaft. It is likely that the oil cooler was not properly flushed when the crankshaft was replaced and that metal and other debris remained in the oil, clogged the drain, and caused the piston to fail. ## Factual narrative On June 12, 2014, about 1200 central daylight time, the pilot of an Air Tractor AT 301, N8593S, made a forced landing in a field near Pearsall, Texas, following a loss of engine power. The pilot, the sole occupant on board, was not injured. The airplane was substantially damaged. The airplane was registered to Matt Fitch and operated Smith Flying Service, doing business as Fitch Flying Service, of Pearsall, Texas, under the provisions of 14 Code of Federal Regulations Part 137 as an aerial application flight. Visual meteorological conditions prevailed at the time of the accident, and no flight plan had been filed. The local flight originated from Pearsall about 1140.According to the pilot, he returned to the airport after spraying a corn field and noticed the cylinder head temperature was high. After landing the engine cylinders were checked for discrepancies; none were found, so he decided to continue spraying. He took off and returned to the corn field. As he pulled up from a spray run, the engine started to vibrate and lose power. He made a forced landing in a nearby field. Examination of the airplane revealed both wings had sustained substantial damage during the forced landing. According to the operator, the engine had accrued about 11 hours since the engine received extensive maintenance, including the replacement of a crankshaft. The engine was shipped to Tulsa Engines in Tulsa, Oklahoma, where, on September 3, it was partially disassembled and examined under the auspices of a Federal Aviation Administration inspector. According to the FAA inspector's report, there was a large amount of metal in the oil drain. It was noted that the number 2 cylinder front spark plug was loose. After removing all the spark plugs, an attempt was made to rotate the engine. It was seized. Numbers 4, 5, 6, and 7 cylinders had oil; number 4 cylinder had more oil. After some difficulty in removing the no. 1 cylinder, it was discovered that the piston rod had broken at the link pin. No other rods were broken. The link pin was scored and there was evidence of oil starvation of the rod bearing. ## Aircraft - Registration: [N8593S](https://openairdocs.org/deregistered/N8593S-2016-10-25), registration cancelled 2016-10-25, S/N 301-0157, built 1978 (OpenAirDocs) - Reported make and model: AIR TRACTOR INC AT 301 (NO SERIES) - 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: 301-0157 - Year built: 1978 - Airframe hours: 8357 - Engines: P&W R 1340-AN-1 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Smith Company Flying Service, doing business as Fitch Flying Service - Registered owner: Matt Fitch - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, May 27, 2014, 11 hours before - Departed: T30, Pearsall, TX - Destination: T30, Pearsall, TX ## 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 October 4, 2013; seat: single; restraint: 4-point; flight hours: 472 total, 220 in this make and model, 415 as pilot in command, 150 in the last 90 days, 11 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 150° at 12 knots, gusting 18 - Visibility: 9 statute miles - Lowest ceiling: none - Temperature: 93 °F, dew point 72 °F - Altimeter: 29.82 inHg - Observed at: KCOT, 23 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 20140612011769A](https://openairdocs.org/incident/20140612011769A), Jun 12, 2014: Air Tractor Inc AT-301, Pearsall, TX, Substantial damage. While dispensing material over application area, pilot reported he started a climb when the engine started vibrating and losing power. The pilot made a forced… ## Other investigations on N8593S (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 FTW81DPG70](https://openairdocs.org/ntsb/FTW81DPG70), Sep 30, 1981: Air Tractor AT-301 (N8593S), Lonoke, AR, substantial damage ## Docket (7 files) The files NTSB released with the investigation on May 26, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=89431. 10.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40426511&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Addendum to NTSB Accident Report (item 2, .PDF, 597 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40426512&FileExtension=.PDF&FileName=Addendum%20to%20NTSB%20Accident%20Report-Redacted.PDF - E-Mail from Troy Fields (item 3, .PDF, 70 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40426513&FileExtension=.PDF&FileName=E-Mail%20from%20Troy%20Fields-Redacted.PDF - Photo 1 – N8593 sitting on blocks after it was recovered from the accident site (item 4, .PDF, 207 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40426904&FileExtension=.PDF&FileName=Photo%201%20%E2%80%93%20%20N8593%20sitting%20on%20blocks%20after%20it%20was%20recovered%20from%20the%20accident%20site-Master.PDF - Photo 2 – A close-up view of the engine and propeller. Note the lower propeller blade is bent aft 90 degrees (item 5, .PDF, 221 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40426907&FileExtension=.PDF&FileName=Photo%202%20%E2%80%93%20A%20close-up%20view%20of%20the%20engine%20and%20propeller.%20Note%20the%20lower%20propeller%20blade%20is%20bent%20aft%2090%20degrees-Master.PDF - Photo 3 – Removal of the no. 1 cylinder head revealed a broken connecting rod. Note the damage to the cylinder skirt (item 6, .PDF, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40426908&FileExtension=.PDF&FileName=Photo%203%20%E2%80%93%20Removal%20of%20the%20no.%201%20cylinder%20head%20revealed%20a%20broken%20connecting%20rod.%20Note%20the%20damage%20to%20the%20cylinder%20skirt-Master.PDF - Photo 4 - Further disassembly revealed the upper segment of the connecting rod still attached to the wrist pin (item 7, .PDF, 2.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40426910&FileExtension=.PDF&FileName=Photo%204%20-%20Further%20disassembly%20revealed%20the%20upper%20segment%20of%20the%20connecting%20rod%20still%20attached%20to%20the%20wrist%20pin-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.