# NTSB SEA06CA103: Cessna 172M, N12808, Hamilton, MT, May 20, 2006 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: May 20, 2006, 14:00 local (20:00 UTC) - Place: Hamilton, MT - Coordinates: 46.254444, -114.125556 - Nearby events: https://openairdocs.org/map.md?lat=46.2544&lon=-114.1256&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report October 3, 2006 - Report: Approved by Office Director - NTSB case key (mKey): 63722 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA06CA103 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/63722/pdf - Page: https://openairdocs.org/ntsb/SEA06CA103 ## Probable cause The pilot's inadequate compensation for the wind conditions during the landing roll which resulted in his failure to maintain directional control. Factors included variable winds and gusty crosswinds. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, landing - roll - directional control - not maintained, pilot in command (cause) - compensation for wind conditions - inadequate, pilot in command (cause) - weather condition - variable wind (contributing factor) - weather condition - crosswind (contributing factor) - weather condition - gusts (contributing factor) ## Analysis As the pilot neared the airport, he was advised by the UNICOM operator that the winds were 270 degrees at 15 knots, gusting to 25 knots. As he rolled out on a left downwind for runway 16, the pilot determined that there was a strong crosswind due to the amount of crab required to hold a ground track parallel to the runway. As the pilot was turning onto final, the UNICOM operator advised him that at that point in time, the winds were blowing at 10 knots. In order to maintain the proper ground track on final, the pilot crabbed the aircraft into the wind, and then switched to a wing-low forward slip on short final. Although the touchdown was uneventful, about 50 feet into the ground roll, the aircraft encountered a strong crosswind gust from the right. The pilot was unable to adequately compensate for the effects of the gust, and the aircraft's right wing lifted, and the aircraft headed toward the left side of the runway. After departing the runway, the aircraft entered a large ditch, impacting its far side with sufficient force to result in substantial damage. After the accident, it was determined that due to building weather in the nearby mountains, the winds in the area were almost constantly changing direction and velocity. ## Factual narrative On May 20, 2006, approximately 1400 mountain daylight time, a Cessna 172M, N12808, departed the runway during the landing roll, and collided with the terrain of a nearby ditch at Ravalli County Airport, Hamilton, Montana. The private pilot and his three passengers where not injured, but the aircraft, which is owned and operated by Northstar Aviation, sustained substantial damage. The 14 CFR Part 91 personal pleasure flight, which departed Bozeman, Montana, about 90 minutes prior to the accident, was being operated in visual meteorological conditions. The aircraft had been on a visual flight rules flight plan. According to the pilot, as he neared the airport he was advised by the UNICOM operator that the winds were 270 degrees at 15 knots, gusting to 25 knots. As he rolled out on a left downwind for runway 16, the pilot determined that there was a strong crosswind due to the amount of crab required to hold a ground track parallel to the runway. As the pilot was turning onto final, the UNICOM operator advised him that at that point in time, the winds were blowing at 10 knots. In order to maintain the proper ground track on final, the pilot crabbed the aircraft into the wind, and then switched to a wing-low forward slip on short final. Although the touchdown was uneventful, about 50 feet into the ground roll, the aircraft encountered a strong crosswind gust from the right. The pilot was unable to adequately compensate for the effects of the gust, and the aircraft's right wing lifted, and the aircraft headed toward the left side of the runway. After departing the runway, the aircraft entered a large ditch, impacting its far side with sufficient force to result in substantial damage. After the accident, it was determined that due to building weather in the nearby mountains, the winds in the area were almost constantly changing direction and velocity. ## Aircraft - Registration: [N12808](https://openairdocs.org/deregistered/N12808-2007-01-23), registration cancelled 2007-01-23, S/N 17262278, built 1973 (OpenAirDocs) - Reported make and model: Cessna 172M - Registry model: [Cessna 172M](https://openairdocs.org/model/cessna-172m) (registry code 2072418) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17262278 - Engines: Lycoming O-320-E2C reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Northstar Aviation, Inc. - Airworthiness certificate: Standard, Normal - Departed: KBZN, Bozeman, MT - Destination: 6S5, Hamilton, MT - Flight plan: VFR - Airport: 6S5, Ravalli County Airport, runway 16 ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 49; private; airplane ratings: single-engine land; medical: class 3; flight hours: 74 total, 5 in this make and model, 21 in the last 90 days, 5 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 15 knots, gusting 25 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.