# NTSB WPR11CA191: Cessna 172N, N492SF, Snohomish, WA, April 6, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: April 6, 2011, 14:00 local (21:00 UTC) - Place: Snohomish, WA - Coordinates: 47.904724, -122.1025 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.9047&lon=-122.1025&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 20, 2011 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 78804 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11CA191 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/78804/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=78804 - Page: https://openairdocs.org/ntsb/WPR11CA191 ## Probable cause The pilot's failure to maintain clearance from a hangar while taxiing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Object/animal/substance: residence/building](https://openairdocs.org/ntsb-findings/03022022): Environmental issues › Physical environment · Response/compensation (probable cause); cases with it: [Cessna 172N, 3 cases](https://openairdocs.org/ntsb-findings/03022022/cases.md?model=2072434), [All aircraft, 58 cases](https://openairdocs.org/ntsb-findings/03022022/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Cessna 172N, 150 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2072434), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [Cessna 172N, 15 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=2072434), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Taxi: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 172N, 134 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2072434), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that while taxiing to the parking area after landing, he noticed that the steering became difficult. He added power and pulled back on the control yoke, noting that the aircraft movement became smooth. As he initiated a right turn to the parking area, the airplane suddenly moved to the left and the left wing struck a hangar. The left wing sustained structural damage. He further reported that following the collision, he turned off the engine, exited the airplane, and noticed that the nose wheel tire was flat. The pilot reported that there were no additional mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation. ## Factual narrative The pilot reported that while taxing to the parking area after landing, he noticed that the steering became difficult. The pilot added power and pulled back on the control yoke, noting that the aircraft movement became smooth. As he initiated a right turn to the parking area, the airplane suddenly moved to the left and the left wing struck a hangar. The left wing sustained structural damage. The pilot further reported that following the collision, he shut down the engine, exited the airplane, and noticed that the nose wheel tire was flat. The pilot reported that there were no additional mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation. ## 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: 9226 - Engines: LYCOMING O-320-H2AD 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: R. Desselle - Registered owner: Snohomish Flying Service Inc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 28, 2010, 19 hours before - Departed: S43, Snohomish, WA - Destination: S43, Snohomish, WA - Airport: S43, Harvey Field Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 73; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review September 21, 2010; seat: left; flight hours: 264 total, 211 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 4 knots - Visibility: 10 statute miles - Lowest ceiling: 3,500 ft broken - Temperature: 45 °F, dew point 32 °F - Altimeter: 29.82 inHg - Observed at: PAE, 7 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 20110406005719A](https://openairdocs.org/incident/20110406005719A), Apr 6, 2011: Cessna 172N, Snohomish, WA, Substantial damage. Nose tire went flat during taxi after flight. Pilot elected to continue to taxi although he knew there was a problem. During attempt to park in taxi spot, hit… ## 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 SEA06LA049](https://openairdocs.org/ntsb/SEA06LA049), Jan 31, 2006: Cessna 172N (N492SF), Snohomish, WA, substantial damage. 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. ## Docket (1 files) The files NTSB released with the investigation on April 19, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=78804. 303 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 303 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40346558&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF 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.