# NTSB LAX96LA215: Beech A36TC, N214MS, Sonora, CA, June 2, 1996 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 2, 1996, 11:40 local (18:40 UTC) - Place: Sonora, CA - Coordinates: 37.98085, -120.39051 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.9808&lon=-120.3905&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report September 5, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 29457 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX96LA215 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29457/pdf - Page: https://openairdocs.org/ntsb/LAX96LA215 ## Probable cause failure of the number 1 connecting rod due to oil starvation caused by inadequate bearing crush. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, cruise - normal - engine assembly,bearing - blocked(total) (cause) - engine assembly,connecting rod - failure (cause) - engine assembly,connecting rod - starvation (cause) - Forced landing, emergency descent/landing - In flight collision with object, emergency descent/landing - terrain condition - none suitable (contributing factor) - object - tree(s) ## Analysis The flight was level at 17,500 feet msl when 40 minutes into the flight the engine began to run extremely rough. This lasted for about 10 to 15 seconds when the engine abruptly stopped. Postaccident examination of the engine revealed that the number 1 connecting rod failed causing a catastrophic failure of the engine. Subsequent examination of the engine revealed that the number 1 main bearing oil supply hole had been blocked from supplying oil to the number 1 connecting rod. Examination of the number 1 main bearing halves revealed that there were operational movements indicated on a bearing half. Evidence was found to indicate the half had fractured/disintegrated and blocked the oil supply hole. The number 1 connecting rod then failed from oil starvation. ## Factual narrative On June 2, 1996, about 1140 hours Pacific daylight time a Beech A36TC, N214MS, was substantially damaged during a forced landing near Sonora, California. Visual meteorological conditions prevailed for the personal cross-country flight and no flight plan was filed. The pilot and passenger received minor injuries. The flight originated at Reno, Nevada, on the day of the accident destined for Lancaster, California. The pilot reported that they were in level flight at 17,500 feet msl. About 40 minutes into the flight the engine began to run extremely rough. This lasted for about 10 to 15 seconds when the engine abruptly stopped. A postaccident examination of the engine revealed that the number 1 connecting rod failed at the crankshaft. The failed rod components/pieces were sent to the Safety Board Materials Laboratory Division for examination. According to the examination of the submitted pieces, they had all been subjected to extensive post-separation mechanical and heat damage. Examination of the limited undamaged portions of the fractures revealed features typical of over stress separation. The entire engine was shipped to the manufacturer's facility at Mobile, Alabama. The engine was subjected to additional analysis under FAA oversight. According to the report, the number 1 main bearing oil supply hole had been blocked from supplying oil to the number 1 connecting rod. The rod failed due to oil starvation. One half of the number 1 main bearing revealed evidence of operational movement leading to a fracture/disintegration of the bearing half. ## Aircraft - Registration: [N214MS](https://openairdocs.org/deregistered/N214MS-1998-05-21), registration cancelled 1998-05-21, S/N EA64 (OpenAirDocs) - Reported make and model: Beech A36TC - Registry model: [Beech A36TC](https://openairdocs.org/model/beech-a36tc) (registry code 1151603) (OpenAirDocs) - Category: Airplane - Serial number: EA-64 - Engines: Continental TSIO-520-UB 300 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Registered owner: Murphy Safety Switch Of Calif. - Airworthiness certificate: Standard, Normal - Departed: RNO, RENO, NV - Destination: WJF, LANCASTER, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 3,465 total, 1,300 in this make and model, 3,335 as pilot in command, 14 in the last 90 days, 7 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 93 °F, dew point 57 °F - Observed at: STK ## 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 19960602012269A](https://openairdocs.org/incident/19960602012269A), Jun 2, 1996: Beech A36TC, Sonora, CA, Substantial damage. Lost power en route. Had thrown a rod. Oil blocked on rod bearing caused siezure and rod to break. 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.