# NTSB CEN21LA316: Cessna 172F, N5340R, Eagle Butte, SD, July 11, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: July 11, 2021, 09:15 local (15:15 UTC) - Place: Eagle Butte, SD · Wheat field about 2 miles from the airport - Coordinates: 44.989766, -101.2589 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.9898&lon=-101.2589&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 103461 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA316 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103461/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103461 - Page: https://openairdocs.org/ntsb/CEN21LA316 ## Probable cause A total loss of engine power due to the fatigue failure of the No. 6 connecting rod. ## 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 · Fatigue/wear/corrosion (probable cause); cases with it: [Cessna 172F, 3 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=2072414), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Cessna 172F, 3 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=2072414), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna 172F, 10 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2072414), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) ## Analysis The pilot reported that, while in cruise flight, the engine began running rough, and shortly after, lost all power. The pilot executed a forced landing into a wheat field, during which the airplane nosed over and came to rest inverted, resulting in substantial damage to the fuselage and left lift strut. Examination revealed a large hole in the top of the engine case adjacent to the No. 6 cylinder. Further examination revealed that the No. 6 connecting rod failed in fatigue, which resulted in the total loss of engine power. ## Factual narrative On July 11, 2021, about 1000 eastern daylight time, a Cessna 172, N5340R, was substantially damaged when it was involved in an accident near Eagle Butte, South Dakota. The pilot was uninjured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, about 6 miles from Cheyenne Eagle Butte Airport (84D), he noticed that the engine’s oil temperature was high, and he heard a “clattering noise.” He reduced the engine power by about 100 rpm and diverted to 84D. About 2 miles from the airport, the engine lost all power. Unable to reach the runway, he performed a forced landing to a wheat field. During touchdown, the nose wheel impacted rising terrain, the airplane bounced, the nose gear separated, and the airplane nosed over, coming to rest inverted. The airplane sustained substantial damage to the left lift strut and fuselage. Examination revealed a large hole in the top of the engine case adjacent to the No. 6 cylinder. The cylinder and connecting rod were removed and sent for examination at the NTSB laboratory in Washington, DC. The examination of the connecting rod revealed fatigue cracking in multiple locations along the outer surface at the transition from the neck to the crankshaft bore. The fatigue crack propagated about halfway through the connecting rod cross section before the remainder fractured from overstress. The fatigue initiation sites were collocated with deep grinding marks. ## Aircraft - Registration: [N5340R](https://openairdocs.org/deregistered/N5340R-2023-12-11), registration cancelled 2023-12-11, S/N 17252868, built 1965 (OpenAirDocs) - Reported make and model: CESSNA 172F - Registry model: [Cessna 172F](https://openairdocs.org/model/cessna-172f) (registry code 2072414) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17252868 - Year built: 1965 - Airframe hours: 3864.5 - Engines: CONT MOTOR 0-300 SER 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 13, 2021, 12 hours before - Departed: KPIR, Pierre, SD - Destination: Same as departure - Airport: 84D - Equipment: Stall warning system, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review June 23, 2020; seat: left; restraint: lap only; flight hours: 347 total, 300 in this make and model, 347 as pilot in command, 18 in the last 90 days, 12 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 5 knots - Temperature: 64 °F, dew point 48 °F - Altimeter: 30.13 inHg - Observed at: KD07, 32 nm away - METAR: KD07 111156Z AUTO 24005KT 18/09 A3013 RMK AO1 SLP189 7//// T01830094 10217 20150 55002 $ ## 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 20210711010609A](https://openairdocs.org/incident/20210711010609A), Jul 11, 2021: Cessna 172F, Eagle Butte, SD, Substantial damage. July 11, 2021 at 09:45AM central daylight time, a Cessna 172F sustained substantial damage when the aircraft had an engine failure and made an emergency… ## Docket (4 files) The files NTSB released with the investigation on October 13, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103461. 7.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13607342&FileExtension=pdf&FileName=Accident%20Reporting%20Form%206120_Redacted-Rel.pdf - Engine exam summary (item 2, PDF, 4 pages, 615 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13608405&FileExtension=pdf&FileName=Examination%20Summary-Rel.pdf - Materials laboratory factual report (item 3, PDF, 17 pages, 21 photos, 4.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13623321&FileExtension=pdf&FileName=22-016%20-%20Materials%20Lab%20Factual%20Report%20(CEN21LA316)-Rel.pdf - Photos (item 4, PDF, 2 pages, 673 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13607910&FileExtension=pdf&FileName=Photo%20Array-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. --- 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.