# NTSB CHI08LA230: Cessna 172RG, N6520R, Tomahawk, WI, August 2, 2008 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: August 1, 2008, 19:15 local (Aug 2, 2008, 00:15 UTC) - Place: Tomahawk, WI - Coordinates: 45.469444, -89.467224 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.4694&lon=-89.4672&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report June 11, 2009 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 68702 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI08LA230 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/68702/pdf - Page: https://openairdocs.org/ntsb/CHI08LA230 ## Probable cause A total loss of engine power due to a loss of all of the engine's oil as a result of the safety wire on the governor idler gear shaft's oil plug breaking, leading to the oil plug coming unscrewed. Contributing to the accident was the lack of a suitable area for a forced landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng oil sys](https://openairdocs.org/ntsb-findings/01058550): Aircraft › Aircraft power plant · Not specified (probable cause); cases with it: [Cessna 172RG, 2 cases](https://openairdocs.org/ntsb-findings/01058550/cases.md?model=2072438), [All aircraft, 130 cases](https://openairdocs.org/ntsb-findings/01058550/cases.md) - [Fluids: oil](https://openairdocs.org/ntsb-findings/01071020): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Cessna 172RG, 3 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md?model=2072438), [All aircraft, 174 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md) - [Terrain](https://openairdocs.org/ntsb-findings/03021000): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Cessna 172RG, 1 case](https://openairdocs.org/ntsb-findings/03021000/cases.md?model=2072438), [All aircraft, 267 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Cessna 172RG, 3 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=2072438), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Emergency descent: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Cessna 172RG, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2072438), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Cessna 172RG, 3 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2072438), [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 172RG, 10 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072438), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot reported that he noticed smoke in the cabin and turned back to the departure airport. Oil began to accumulate on the windshield, which obscured his forward visibility. He made a five-mile straight-in approach using the airplane's global positioning system. He said that he attempted to maintain 2,500 feet above mean sea level and began to lose engine power about three miles from the airport. The engine "sputtered then froze" about two miles from the airport. The pilot then made a forced landing on a field that the passenger saw out of his window. The pilot said that the airplane came to rest at the end of that field, where it impacted trees at about 30 knots. Subsequent to the accident the propeller and starter ring gear were removed. The oil plug on the nose of the engine case that covers the governor idler gear shaft was not in place and it was found in the cowling. A safety wire that had secured the oil plug was observed attached to engine case with a separation at its plug end. ## Factual narrative On August 1, 2008, about 1915 central daylight time, a Cessna 172RG, N6520R, piloted by a private pilot, sustained substantial damage on impact with terrain following an in-flight loss of engine power near the Tomahawk Regional Airport (TKV), Tomahawk, Wisconsin. The personal flight was operating under 14 CFR Part 91. Visual meteorological conditions prevailed at the time of the accident. No flight plan was on file. The pilot and a passenger sustained minor injuries. The local flight originated from TKV about 1900. The pilot reported that he and his passenger noticed light smoke in the cabin during cruise at 2,500 feet above mean sea level (MSL) about five miles east-northeast of TKV. He turned left to return to TKV and opened the windows to vent the cabin. He stated that all the airplane's instruments indicated normal. After the turn, oil began to accumulate on the windshield, which obscured his forward visibility. He made a five mile straight-in approach using the airplane's global positioning system. He said that he attempted to maintain 2,500 feet MSL and began to lose engine power about three miles from TKV. The engine "sputtered then froze" about two miles from TKV. The pilot made a forced landing on a field that the passenger saw out of his window. The pilot said that the airplane came to rest at the end of that field where it impacted trees at about 30 knots. Subsequent to the accident, the propeller and starter ring gear were removed. The oil plug on the nose of the engine case that covers the governor idler gear shaft was not in place and it was found in the cowling. Safety wire that had secured the plug was observed attached to engine case with a separation at its plug end. The pilot's safety recommendation stated he had accumulated 23 hours of simulated instrument training. He said, "Without the instrument time I am certain the loss of all forward visibility would have been unnerving." ## Aircraft - Registration: [N6520R](https://openairdocs.org/deregistered/N6520R-2010-01-07), registration cancelled 2010-01-07, S/N 172RG0189, built 1979 (OpenAirDocs) - Reported make and model: CESSNA 172RG - Registry model: [Cessna 172RG](https://openairdocs.org/model/cessna-172rg) (registry code 2072438) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 172RG0189 - Airframe hours: 6840 - Engines: LYCOMING O-360-F1A6 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: 6520r LLC - Registered owner: 6520r LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 11, 2007 - Departed: TKV, TOMAHAWK, WI - Airport: TKV, Tomahawk Regional Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review July 23, 2008; seat: left; flight hours: 119 total, 31 in this make and model, 44 as pilot in command, 2 in the last 90 days, 2 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 340° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 52 °F - Altimeter: 29.90 inHg - Observed at: RHI, 17 nm away ## 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 20080801846329A](https://openairdocs.org/incident/20080801846329A), Aug 1, 2008: Cessna 172RG, Tomahawk, WI, Destroyed. (-23) On August 1, 2008 at approximately 1948 central daylight time (CDT), Cessna 172RG, N6520R made an emergency landing 2 miles from Tomahawk (ktkv) airport… 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.