# NTSB CEN18LA311: Cessna 188, N5523S, Watkins, MN, August 2, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 2, 2018, 10:35 local (15:35 UTC) - Place: Watkins, MN - Coordinates: 46.814167, -94.408607 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.8142&lon=-94.4086&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report November 6, 2019 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Flight Standards - NTSB case key (mKey): 97990 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN18LA311 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97990/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97990 - Page: https://openairdocs.org/ntsb/CEN18LA311 ## Probable cause A partial loss of engine power for reasons that could not be determined because a postaccident examination revealed no evidence of preimpact mechanical malfunctions or failures that would have precluded normal operation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Cessna 188, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=2073002), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/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: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Cessna 188, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=2073002), [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: [Cessna 188, 2 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2073002), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis During the agricultural application flight, the commercial pilot noticed a loss of engine speed (rpm) after completing an application pass. He subsequently observed a decrease in engine oil pressure combined with an increase in oil temperature. As he returned for a forced landing to the corn field being sprayed, the oil pressure was about 7 psi. The pilot indicated that the engine was "coughing" at that point, and he decided to shut the engine down; the loss of engine power was not catastrophic. He subsequently landed in the field, and the airplane sustained substantial damage to the right wing. A postaccident examination revealed no evidence of preimpact mechanical malfunctions or failures that would have precluded normal operation. Thus, the reason for the partial loss of engine power could not be determined. ## Factual narrative On August 2, 2018, about 1035 central daylight time, a Cessna 188 airplane, N5523S, was substantially damaged during a forced landing following a partial loss of engine power near Watkins, Minnesota. The pilot was not injured. The airplane was registered to a private individual and operated by Classic Arrow Inc. as a Title 14 Code of Federal Regulations Part 137 agricultural application flight. Day visual meteorological conditions prevailed. The flight was not operated on a flight plan. The local flight originated from the Litchfield Municipal Airport (LJF), Litchfield, Minnesota, about 0945.The pilot reported that the airplane was fully fueled before the flight. After takeoff, he flew about 20 minutes to the field to be sprayed. He proceeded to survey for hazards and completed a few spray passes. He subsequently noted a loss of engine speed (rpm) after completing an application pass. He pushed the propeller control forward in an attempt to increase the engine/propeller speed which was successful for a short period of time. However, the engine speed began to decrease again, and he observed a decrease in oil pressure combined with an increase in the oil temperature. He moved all engine controls – throttle, propeller, and mixture – full forward. As he returned for a forced landing to the corn field being sprayed, the oil pressure was about 7 psi. As the airplane came over the field, the engine was "coughing." After impacting the corn, the airplane "angled up on the nose" before coming to rest. He recalled the weather conditions as "very good," with a light wind, clear sky, and more than 10 miles visibility. The pilot informed a Federal Aviation Administration (FAA) inspector that the loss of engine power was not catastrophic in nature. Rather, the pilot observed the oil pressure dropping with the oil temperature rising and decided to pull the mixture to shut the engine off. He subsequently landed in the corn field just below the airplane. The FAA inspector reported that the airplane sustained substantial damage to the right wing. Postaccident airframe and engine examinations conducted by the inspector revealed no anomalies that could be attributed to a preimpact failure or malfunction. ## Aircraft - Registration: [N5523S](https://openairdocs.org/aircraft/N5523S), registered now, S/N 188-0023, built 1966 (OpenAirDocs) - Reported make and model: Cessna 188 (Undesignat) - Registry model: [Cessna 188](https://openairdocs.org/model/cessna-188) (registry code 2073002) (OpenAirDocs) - Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 188-0023 - Year built: 1966 - Airframe hours: 2700 - Engines: Continental O-470-R 230 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, February 14, 2018 - Departed: LJF, Litchfield, MN - Destination: LJF, Litchfield, MN - Airport: LJF, Litchfield Muni - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 21; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; seat: single; restraint: 4-point; flight hours: 566 total, 124 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 70° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: 3,300 ft broken - Temperature: 64 °F, dew point 55 °F - Altimeter: 30.05 inHg - Observed at: LJF, 14 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 20180802009529A](https://openairdocs.org/incident/20180802009529A), Aug 2, 2018: Cessna 188, Watkins, MN, Substantial damage. Engine oil pressure was dropping and the oil temperature began to rise. Pilot shut engine immediately down and landed in corn field directly below him. ## Docket (4 files) The files NTSB released with the investigation on June 26, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97990. 620 KB in all. - Pilot's Statement (item 1, .PDF, 55 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40473734&FileExtension=.PDF&FileName=Pilot%27s%20Statement-Master.PDF - FAA Inspector Statement (item 2, .PDF, 92 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40473735&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Master.PDF - Maintenance Records - Airframe (item 3, .PDF, 142 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40473736&FileExtension=.PDF&FileName=Maintenance%20Records%20-%20Airframe-Master.PDF - Maintenance Records - Engine (item 4, .PDF, 331 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40473737&FileExtension=.PDF&FileName=Maintenance%20Records%20-%20Engine-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.