# NTSB WPR11LA038: Cessna T210N, N6179Y, Baggs, WY, November 6, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: November 6, 2010, 14:30 local (20:30 UTC) - Place: Baggs, WY - Coordinates: 41.467777, -107.768058 - Nearby events: https://openairdocs.org/map.md?lat=41.4678&lon=-107.7681&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report December 27, 2011 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 77741 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11LA038 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/77741/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=77741 - Page: https://openairdocs.org/ntsb/WPR11LA038 ## Probable cause The failure of a connecting rod cap retaining bolt during cruise flight, which resulted in a loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Cessna T210N, 2 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2073456), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md) - [Terrain: rough terrain](https://openairdocs.org/ntsb-findings/03021015): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Cessna T210N, 2 cases](https://openairdocs.org/ntsb-findings/03021015/cases.md?model=2073456), [All aircraft, 442 cases](https://openairdocs.org/ntsb-findings/03021015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna T210N, 9 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2073456), [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: [Cessna T210N, 9 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2073456), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna T210N, 14 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2073456), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that during cruise flight, he heard and felt a solid “thump” that seemed to come from the engine compartment. Shortly thereafter, the oil pressure dropped and the engine eventually lost power. The pilot initiated a power-off forced landing on a rough and rutted dirt road. Although the initial touchdown was successful, due to the condition of the road, the pilot was unable to keep the airplane on the road surface, and it entered rough and uneven terrain. The nose of the airplane then dug into the terrain, and the airplane nosed over. The postaccident engine examination found that most of the engine oil had exited through a hole in the crankcase. Further examination found that the No. 1 connecting rod cap retaining bolt failed, ultimately resulting in the separation of the connecting rod from the crankshaft. The damage to the fracture surface on the portion of the retaining bolt that was recovered and the missing remainder of the bolt precluded any determination of bolt failure mode. ## Factual narrative On November 6, 2010, about 1430 mountain daylight time, a Cessna T210N, N6179Y, impacted the terrain during a forced landing about 30 miles north of Baggs, Wyoming. The commercial pilot and his passenger were not injured, but the airplane, which was owned and operated by the pilot, sustained substantial damage. The 14 Code of Federal Regulations Part 91 personal cross-country flight, which departed Broken Bow, Nebraska, about two hours prior to the accident, was en route to Brigham City, Utah. The flight was being operated in visual meteorological conditions. No flight plan had been filed. According to the pilot, while in cruise flight he suddenly heard and felt a solid "thump" that appeared to have come from the area of the engine compartment. Soon thereafter, the oil pressure started to drop and the engine started losing power. About two minutes after the oil pressure started dropping, the engine began making a knocking sound and the propeller began to slow. Eventually the engine stopped producing any power, and the pilot attempted a forced landing on a nearby narrow dirt road. Although the touchdown was successful, the pilot was unable to keep the airplane aligned with the rough and rutted road, and it therefore departed the road surface and went into the nearby rough and uneven terrain. After the airplane encountered the rough terrain, its nose dug in, and it flipped over onto its top. An on-scene inspection by an Airworthiness Inspector from the Casper Flight Standards District Office (FSDO) determined that there was a hole in the side of the engine crankcase, and that much of the engine oil had escaped through that hole. The airplane was recovered to the facilities of Beegles Aircraft Service, in Greeley, Colorado, where it underwent a full teardown inspection under the oversight of a Federal Aviation Administration (FAA) Airworthiness Inspector from the Denver FSDO. The teardown included inspection of all engine accessories and external components, and the separation of the two crankcase halves in order to remove and inspect all the internal engine components. No anomalies, contamination, or evidence of malfunction were found in any of the engine accessories, to include the magnetos, ignition harness, sparkplugs, fuel pump, oil pump, fuel manifold valve, fuel injection nozzles, oil cooler, and oil filter. The cylinders, piston, and valve train were all without evidence of anomaly or malfunction. Upon splitting the crankcase it was determined that all the main journal bearings showed significant wear, with some degree of the underlying copper material showing through; but none of the journals displayed evidence of significant thermal damage. In addition there was no significant thermal damage to any of the crankshaft main journals, and no evidence of hard particle passage on the main journals surfaces. It was noted that the slot that holds the retention tang for one-half of the number two main bearing had elongated, but there was noevidence that the main bearing had shifted, or that the flow of lubricating oil had been interrupted. An inspection of the crankshaft revealed evidence of severe thermal stress in the area of the number one and number two connection rod journals. Although the crankshaft oil transfer tubes were clear and unrestricted, both connecting rod journals displayed characteristics consistent with heat buildup due to a localized lack of lubrication. Both had turned a light reddish tan color and both were completely void of any lubrication. The number two connecting rod was still attached to its journal, but the large end of the connecting rod, as well as the rod cap retaining bolts, were reddish tan in color and void of lubrication. The number one connecting rod had separated from its journal, and one side of the rod cap was found to be without its retaining bolt. The greatly distorted large end of the connecting rod, as well as the remaining rod cap retaining bolt, was also reddish tan in color and void of lubrication. The castellated nut end of the missing rod cap retaining bolt, along with damaged pieces of connecting rod bearing material, was found in the oil sump. The recovered bolt section, which had fractured and sustained damage in the area of the fracture, did not display any evidence of being exposed to the overheat condition. Due to the damage to the area around the fracture surface on the nut end of the bolt, and due to the fact that the head end of the bolt was not located, the mode of failure of the bolt could not be established. A review of the aircraft log books revealed that from October 3, 2007, to May 3, 2010, a period of 31 months, the airplane had accumulated a total of 4.0 hours of flight time. During that period of time, there were no annual inspections performed, and there were no entries in the engine log book to indicate that the relevant engine preservation procedures, defined in Teledyne Continental Motors Service Letter SIL99-1, had been complied with. From May 3, 2010, to October 20, 2010, the airplane, then under new ownership, accumulated approximately 242 hours of flight time. The log book review also revealed that at the time of the accident, the engine had accumulated 1,591 hours since its last major overhaul. According to Teledyne Continental Motors Service Letter SIL98-9A, the recommended time between major overhauls for the TSIO-520-R series engine is 1,400 hours. A log book entry also indicated that on October 20, 2010, about two weeks before the accident, the number two and three cylinders were reinstalled after being overhauled due to low compression. ## Aircraft - Registration: [N6179Y](https://openairdocs.org/deregistered/N6179Y-2016-07-29), registration cancelled 2016-07-29, S/N 21064283, built 1981 (OpenAirDocs) - Reported make and model: CESSNA T210N - Registry model: [Cessna T210N](https://openairdocs.org/model/cessna-t210n) (registry code 2073456) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 21064283 - Airframe hours: 3044 - Engines: CONT MOTOR TSIO-520 SER 310 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Justin A. Thompson - Registered owner: CMS Automotive - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 30, 2010 - Departed: KBBW, Broken Bow, NE - Destination: KBMC, Brigham City, UT ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 40; injuries: none; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review May 6, 2009; seat: left; flight hours: 824 total, 289 in this make and model, 691 as pilot in command, 116 in the last 90 days, 40 in the last 30 days, 10 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 28 °F, dew point 25 °F - Altimeter: 29.95 inHg ## Docket (3 files) The files NTSB released with the investigation on November 25, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=77741. 1.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 270 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357302&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Excerpt from Continental Motors Report (item 2, .PDF, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357953&FileExtension=.PDF&FileName=Excerpt%20from%20Continental%20Motors%20Report-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 3, .PDF, 54 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357979&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.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.