# NTSB SEA02LA025: Cessna 210L, N1713X, Great Falls, MT, January 9, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 9, 2002, 11:10 local (18:10 UTC) - Place: Great Falls, MT - Coordinates: 47.289882, -111.340797 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.2899&lon=-111.3408&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 28, 2002 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 54165 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA02LA025 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/54165/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=54165 - Page: https://openairdocs.org/ntsb/SEA02LA025 ## Probable cause The pilot's intentional continuation of a visual flight rules (VFR) flight into instrument meteorological conditions (IMC), and his failure to maintain clearance from the terrain. Factors include low ceilings, snow, mountainous/hilly terrain, and trees. ## Analysis While attempting to fly through an area of mountainous/hilly terrain, the pilot encountered lowering ceilings and snow, and as he continued, got off of his planned course. Although he was initially able to remain below the clouds, he eventually entered an area where his attempts to maintain clearance from the terrain resulted in the aircraft entering the bottom portion of the cloud layer. Because he was having difficulty keeping visual contact with the terrain, he initiated a course-reversal turn. During the turn, the aircraft clipped a tree top, and then impacted a number of other trees. Prior to his departure, the pilot received two weather briefings. The briefing he received earlier in the day indicated his planned route would be VFR at the time of his departure. The briefing he received about 90 minutes prior to departure indicated that the route would be mostly VFR, but that there was an update that showed areas of possible mountain obscuration. ## Factual narrative On January 9, 2002, approximately 1110 mountain standard time, a Cessna 210L, N1713X, impacted trees while the pilot was trying to execute a low-altitude course reversal in mountainous terrain about 40 miles southeast of Great Falls, Montana. The private pilot, who was the sole occupant, was not injured, but the aircraft, which was owned by Sletton Construction Company, of Great Falls, Montana, sustained substantial damage. The 14 CFR Part 91 business flight, which departed Great Falls in visual meteorological conditions about 25 minutes before the accident, entered an area of instrument meteorological conditions while en route to Cheyenne, Wyoming. No flight plan had been filed. The ELT was not set off by the impact, but was later activated by the pilot. According to the pilot, while heading toward Cheyenne, lowering clouds, snow, and rising terrain made him stray from the route that he had planned. As he tried to maneuver through the mountainous terrain, he was initially able to stay below the clouds and clear of the ground. Eventually, he entered an area where his attempts to maintain clearance from the terrain resulted in the aircraft entering the bottom of the cloud layer. Because he was having trouble maintaining visual contact with the ground through the clouds and snow, he attempted to reverse his course, but clipped a tree during the turn. He immediately rolled the aircraft wings-level, and tried to maintain control as it collided with other trees and fell to the snow covered terrain. After the aircraft came to a stop, and the pilot assured himself there was not going to be a fire, he activated the ELT. Around 0700 on the morning of the accident, the pilot called Great Falls Automated Flight Service Station for a weather briefing. At that time, he was advised that his planned route of flight was forecast to be VFR at the time he intended to depart. About 90 minutes prior to his departure, the pilot called back for an update briefing. He was then advised that although the route was still forecast to be mostly VFR, there was now an update that showed possible areas of mountain obscuration. At that time, the briefer advised the pilot that VFR flight was not recommended in areas of the forecast mountain obscuration. In the Operator Safety Recommendation portion of the NTSB Form 6120.1/2 (How Could This Accident Have Been Prevented), the pilot stated, "Pilot should have turned around and gone back when weather deteriorated." ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, maneuvering - turn to reverse direction - vfr flight into imc - intentional, pilot in command (cause) - clearance - not maintained, pilot in command (cause) - weather condition - low ceiling (contributing factor) - weather condition - snow (contributing factor) - terrain condition - mountainous/hilly (contributing factor) - object - tree(s) (contributing factor) ## Aircraft - Registration: [N1713X](https://openairdocs.org/deregistered/N1713X-2004-05-05), registration cancelled 2004-05-05, S/N 21060735 (OpenAirDocs) - Reported make and model: Cessna 210L - Registry model: [Cessna 210L](https://openairdocs.org/model/cessna-210l) (registry code 2073448) (OpenAirDocs) - Category: Airplane - Serial number: 21060735 - Airframe hours: 4487 - Engines: Continental IO-520-L8B 285 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Registered owner: Sletton Construction Co. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 8, 2001, 56 hours before - Departed: GTF, Great Falls, MT - Destination: CYS, Cheyenne, WY ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review August 3, 2000; seat: left; flight hours: 1,447 total, 486 in this make and model, 1,369 as pilot in command, 4 in the last 90 days, 4 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Instrument (IMC), Day - Wind: calm - Visibility: 0.5 statute miles - Temperature: 25 °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 20020109000369A](https://openairdocs.org/incident/20020109000369A), Jan 9, 2002: Cessna 210L, Monarch, MT, No damage. (-23) Pilot stated he encountered rapidly deteriorating weather conditions in mountainous terrain. During a turn initiated to reverse course and fly back out… ## Docket (1 files) The files NTSB released with the investigation on January 31, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=54165. 477 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2 (item 1, .PDF, 477 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40378450&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%2F2-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.