# NTSB SEA98LA166: Cessna 175, N8512X, Missoula, MT, August 15, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 15, 1998, 16:20 local (22:20 UTC) - Place: Missoula, MT - Coordinates: 46.84959, -113.989448 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.8496&lon=-113.9894&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 15, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 43739 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA98LA166 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/43739/pdf - Page: https://openairdocs.org/ntsb/SEA98LA166 ## Probable cause A complete loss of crankcase oil due to a missing oil filler tube followed by the failure of a connecting rod. Factors include encountering a small pine tree during the landing roll. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, cruise - fluid,oil - exhaustion (cause) - engine assembly,connecting rod - fractured (cause) - Forced landing, emergency descent/landing - Nose over, landing - roll - object - tree(s) (contributing factor) ## Analysis While in cruise flight, the pilot smelled smoke and noticed a loss of oil pressure. He therefore found an open field in which he could make an emergency landing. After arriving over the field, the engine stopped running and the pilot made a forced landing. During the landing roll, the aircraft's nose gear was torn off when it hit a small pine tree. After the gear was torn off, the aircraft nosed over. A post-accident inspection of the engine revealed that the number three connecting rod had failed and passed through the crankcase. It was also noted that the oil filler tube was missing, and no oil was found in the crankcase. ## Factual narrative On August 15, 1998, approximately 1620 mountain daylight time, a Cessna 175, N8512X, nosed over during a power-off forced landing about 15 miles southwest of Missoula, Montana. The private pilot and his passenger were not injured, but the aircraft, which was owned and operated by Hinkle Aviation, of Caldwell, Idaho, sustained substantial damage. The 14 CFR Part 91 personal pleasure flight, which departed Kalispell, Montana, about 50 minutes prior to the accident, was being operated in visual meteorological conditions. No flight plan had been filed, and there was no report of an ELT activation. According to the pilot, while at cruise, smoke started accumulating in the cabin, so he started checking for abnormal instrument indications. Soon thereafter, he noticed that the oil pressure had dropped to zero. He then reversed course in order to return to an open field he had flown over a few minutes earlier. As he arrived over the field, the engine stopped running, and he attempted a forced landing. His touchdown was successful, but as the aircraft neared the edge of the field, the nose gear hit a small pine tree. When the gear hit the tree, the entire nose gear assembly was torn from the fuselage and the aircraft nosed over. A post accident inspection of the engine revealed that the oil filler tube had separated from the engine and was not found at the accident site. Almost all of the engine oil had drained from the crankcase, and the number three connecting rod had failed and come through the side of the case. ## Aircraft - Registration: [N8512X](https://openairdocs.org/deregistered/N8512X-2013-04-29), registration cancelled 2013-04-29, S/N 17557112, built 1962 (OpenAirDocs) - Reported make and model: Cessna 175 - Registry model: [Cessna 175C](https://openairdocs.org/model/cessna-175c) (registry code 2072508) (OpenAirDocs) - Registry engine: [Continental GO-300 series](https://openairdocs.org/engine/continental-go-300-series) (registry code 17024, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17557112 - Airframe hours: 1999 - Engines: Continental GO300-E 175 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Bill Hinkle, doing business as Hinkle Aviation - Registered owner: Hinkle Aviation - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, July 25, 1998, 20 hours before - Departed: S27, KALISPELL, MT - Destination: EUL, CALDWELL, ID ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 77 total, 7 in this make and model, 35 as pilot in command, 7 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 45° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °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 19980815031349A](https://openairdocs.org/incident/19980815031349A), Aug 15, 1998: Cessna 175C, Alberton, MT, Substantial damage. (-23)The pilot stated that his wife noticed smoke in the cockpit. When he removed his sunglasses, he confirmed that there was smoke in the cockpit. He also… 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.