# NTSB SEA06LA049: Cessna 172N, N492SF, Snohomish, WA, January 31, 2006 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 31, 2006, 10:25 local (18:25 UTC) - Place: Snohomish, WA - Coordinates: 47.913612, -122.108886 - Nearby events: https://openairdocs.org/map.md?lat=47.9136&lon=-122.1089&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 30, 2006 - Report: Approved by Office Director - Parties: FAA/FSDO - NTSB case key (mKey): 63179 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA06LA049 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/63179/pdf - Page: https://openairdocs.org/ntsb/SEA06LA049 ## Probable cause Carburetor heat was not used during the initial climb in probable serious carburetor icing conditions during cruise power. Carburetor icing conditions and wet terrain were factors. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, takeoff - initial climb - weather condition - carburetor icing conditions (contributing factor) - carburetor heat control - not activated (cause) - fuel system,carburetor - ice - Forced landing, emergency landing after takeoff - On ground/water encounter with terrain/water, emergency landing - terrain condition - water (contributing factor) - Nose over, emergency landing ## Analysis The pilot reported that shortly after takeoff, the engine lost power after the aircraft attained an altitude of about 250 to 300 feet above ground level. The flight instructor took over the flight controls and accomplished an off airport landing in an open field that was flooded by recent rains. During the landing roll, the airplane nosed over. The wings and a lift strut were damaged, fuel was leaking from the fuel tank(s), and the top of the vertical stabilizer was crushed. After the wreckage was recovered the engine was prepared for an engine run. It was found that the engine started and ran smoothly with no anomalies noted during the run that lasted about 5 minutes in duration. The nearest weather reporting facility located 6 nautical miles to the west was reporting a temperature of 42 degrees F, and dew point of 36 degrees F. The carburetor icing probability chart indicated that for the reported temperature and dew point, the aircraft was operating in probable serious carburetor icing conditions at cruise or climb power. ## Factual narrative On January 31, 2006, about 1025 Pacific standard time, a Cessna 172N, N492SF, registered to and operated by Snohomish Flying Service as a 14 CFR Part 91 local instructional flight, experienced a loss of engine power shortly after takeoff from Harvey Field, Snohomish, Washington. During the off airport landing in a flooded pasture, the airplane nosed over. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft was substantially damaged and the flight instructor and airline transport pilot receiving instruction for an add-on rating/certificate were not injured. Both pilots reported that shortly after takeoff, the engine lost power after the aircraft attained an altitude of about 250 to 300 feet above ground level. The flight instructor took over the flight controls and accomplished an off airport landing in an open field that was flooded by recent rains. During the landing roll, the airplane nosed over. The wings and a lift strut were damaged, fuel was leaking from the fuel tank(s), and the top of the vertical stabilizer was crushed. On February 1, 2006, a Federal Aviation Administration Inspector from the Seattle, Washington, Flight Standards District Office, witnessed the start and run-up of the engine after the wreckage had been recovered from the field. The inspector reported that after the fuel system was flushed out, the engine was started, and after a few minutes ran smoothly. The rpm was increased to 1800 and a magneto check was accomplished with no abnormalities noted. The engine was run for about 5 minutes and then shut down. No evidence of a mechanical failure or malfunction was noted during the engine run. At 0953, the weather facility at Everett, Washington, Paine Field located 6 nautical miles to the west was reporting a temperature of 42 degrees F, and dew point of 36 degrees F. The carburetor icing probability chart indicated that for the reported temperature and dew point, the aircraft was operating in probable serious carburetor icing conditions at cruise or climb power. ## Aircraft - Registration: [N492SF](https://openairdocs.org/aircraft/N492SF), registered now, S/N 17268310, built 1976 (OpenAirDocs) - Reported make and model: Cessna 172N - Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17268310 - Airframe hours: 8729 - Engines: Lycoming O-320-H2AD 160 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Snohomish Flying Service - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 1, 2005, 65 hours before - Departed: S43, Snohomish, WA - Destination: S43 - Airport: S43, Harvey Field ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 49; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter, airplane; medical: class 2; last flight review September 1, 2005; seat: right; flight hours: 6,239 total, 77 in this make and model, 5,857 as pilot in command, 27 in the last 90 days, 11 in the last 30 days - Student pilot; injuries: none - Pilot; age 45; injuries: none; flight instructor, airline transport, commercial; airplane ratings: multi-engine land; instrument ratings: airplane, helicopter; medical: class 1; last flight review September 1, 2005; seat: left; flight hours: 8,506 total, 5 in this make and model, 4,200 as pilot in command, 52 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 150° at 12 knots - Visibility: 10 statute miles - Lowest ceiling: 4,700 ft broken - Temperature: 43 °F, dew point 36 °F - Altimeter: 29.89 inHg - Observed at: PAE, 6 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 20060131002789A](https://openairdocs.org/incident/20060131002789A), Jan 31, 2006: Cessna 172N, Snohomish, WA, Substantial damage. (-23) The pilot and instructor stated normal taxi and run up. Normal take off. During climb out lost power and instructor took over the control. Landed in a… ## Other investigations on N492SF (1) 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. - [NTSB WPR11CA191](https://openairdocs.org/ntsb/WPR11CA191), Apr 6, 2011: Cessna 172N (N492SF), Snohomish, WA, substantial damage. Probable cause: The pilot's failure to maintain clearance from a hangar while taxiing. 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.