# NTSB SEA94LA196: Cessna T210M, N761TK, Rathdrum, ID, July 26, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 25, 1994, 17:57 local (Jul 26, 1994, 00:57 UTC) - Place: Rathdrum, ID - Coordinates: 47.840141, -116.879226 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.8401&lon=-116.8792&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 13, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 41988 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA94LA196 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41988/pdf - Page: https://openairdocs.org/ntsb/SEA94LA196 ## Probable cause THE FATIGUE FAILURE OF THE CRANKSHAFT AND A SLIPPED BEARING. ## 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 - engine assembly,crankshaft - fatigue (cause) - engine assembly,bearing - slipped (cause) - Forced landing, descent - emergency - Nose over, landing - roll - terrain condition - soft ## Analysis THE PILOT REPORTED THAT THE ENGINE LOST POWER WHILE IN CRUISE FLIGHT. A FORCED LANDING WAS MADE TO AN OPEN FIELD WHERE DURING THE LANDING ROLL, THE AIRPLANE NOSED OVER. DURING THE ENGINE INSPECTION, IT WAS FOUND THAT THE CRANKSHAFT BROKE AT THE NUMBER 2 JOURNAL. TESTING REVEALED A FATIGUE CRACK EMANATING FROM THE RADIUS INWARD, AND THE PRESENCE OF SCORE MARKS INDICATE THAT THE BEARING INSERTS SHIFTED AFT DURING ENGINE OPERATION AND WERE RUBBING AGAINST THE JOURNAL RADIUS. ## Factual narrative On July 25, 1994 at 1757 Pacific daylight time, a Cessna T210M, N761TK, experienced a loss of engine power while in cruise flight. The pilot initiated a forced landing to an open field near Rathdrum, Idaho. During the landing roll, the nose gear collapsed and the airplane nosed over. Visual meteorological conditions prevailed at the time and a U.S. Forest Service flight following flight plan was filed. The airplane was substantially damaged and the commercial pilot was not injured. The flight had departed from Bonners Ferry, Idaho, on July 25, 1994 at 1730 and was en route to Spokane, Washington. The pilot reported that while cruising at 1,000 feet above ground level, the engine lost power. The pilot initiated a forced landing to an open field. During the landing roll, the nose gear collapsed and the airplane nosed over. During an engine inspection, it was found that the crankshaft was broken at the aft radius of the number two main journal. The crankshaft was removed and sent to the National Transportation Safety Board Materials Laboratory for a metallurgical examination. The specialist reported that the fatigue crack emanated from multiple origins at the radius between the number two main journal and the crankcheek. Most of the number two main journal bearing surface contained rotational wear marks and ladder cracking. Evidence of bearing insert metal had transferred onto the journal surface. Heat discoloration, circumferential scoring damage, and ladder cracking were also visible at the aft radius of this journal. The specialist reported that evidence on the other bearing journals indicated light to moderate scoring and heat damage on the surfaces of all six rod journals and main journals. The number three main bearing journal was severely overheated and scored. All of the rod journals bearing inserts indicated evidence of excessive rubbing and circumferential scoring. ## Aircraft - Registration: [N761TK](https://openairdocs.org/aircraft/N761TK), registered now, S/N 21062503, built 1978 (OpenAirDocs) - Reported make and model: CESSNA T210M - Registry model: [Cessna T210M](https://openairdocs.org/model/cessna-t210m) (registry code 2073451) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 21062503 - Airframe hours: 3174 - Engines: CONTINENTAL TSIO-520 310 horsepower reciprocating - Damage: Substantial damage - Flight: Positioning, Part 91 - Operator: Felts Field Aviation - Registered owner: Felts Field Aviation - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 14, 1994, 16 hours before - Departed: 65S, BONNERS FERRY, ID - Destination: SFF, SPOKANE, WA - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; flight instructor, commercial; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 7,000 total, 300 in this make and model, 5,000 as pilot in command, 80 in the last 90 days, 60 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 225° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 95 °F ## 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 19940725047369A](https://openairdocs.org/incident/19940725047369A), Jul 25, 1994: Cessna T210M, Rathdrum, ID, Substantial damage. Engine failed en route. Nosed over on forced landing. Crankshaft had broken. 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.