# NTSB DEN02TA052: Beech 58P, N123Z, Grand Junction, CO, June 10, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: June 9, 2002, 20:30 local (Jun 10, 2002, 02:30 UTC) - Place: Grand Junction, CO - Coordinates: 39.122501, -108.526664 - Nearby events: https://openairdocs.org/map.md?lat=39.1225&lon=-108.5267&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 6, 2002 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 54926 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN02TA052 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/54926/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=54926 - Page: https://openairdocs.org/ntsb/DEN02TA052 ## Probable cause the pilot's inadvertent flight into adverse weather conditions. A factor contributing to the accident was the terrain-induced turbulence. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, cruise - flight into adverse weather - inadvertent, pilot in command (cause) - weather condition - turbulence,terrain induced (contributing factor) - wing,spar - bent - wing,skin - buckled ## Analysis The pilot departed Grand Junction, Colorado (GJT) on fire assignment as a Forest Service lead airplane, to the Coal Seam Fire in Garfield County, Colorado, in the vicinity of Glenwood Springs. The pilot reported experiencing low-level wind shear and light, moderate, and severe turbulence from just after takeoff through arriving at the area of operation. Following a reconnaissance of the fire, the pilot reported climbing to approximately 5,000 feet agl (above ground level) to avoid the turbulence and wait for wind conditions to improve so that tanker operations (aircraft dropping fire suppressant chemicals on the wildfire) could begin. The pilot reported that wind conditions improved and tanker operations commenced. On conclusion of the tanker operations, the pilot returned to GJT. The pilot reported he was in the vicinity of the Book Cliffs, approximately 10 miles northeast of GJT, approximately 2,000 feet agl in a low power descent, and an airspeed of approximately 150-160 knots, when he encountered one significant event of severe turbulence. The pilot reported the winds were out of the southwest at 20 knots with gusts to 29 knots. The airplane continued to GJT and landed uneventfully. The aircraft damage was noted the following morning during a routine preflight inspection. An examination of the airplane showed the top skin of the airplane's left wing, between the fuselage and the left engine nacelle, was buckled. No other anomalies were found. The reported winds at GJT, 34 minutes prior to the event, were 180 degrees at 20 knots with gusts to 28 knots. ## Factual narrative On June 9, 2002, approximately 2030 mountain daylight time, a Beech 58P, N123Z, operated by the U. S. Department of Agriculture (USDA) Forest Service and piloted by an airline transport pilot, was substantially damaged when it encountered severe turbulence, approximately 10 miles east of Grand Junction, Colorado. Visual meteorological conditions prevailed at the time of the accident. The aerial observation flight was conducted in support of wildfire fighting efforts near Glenwood Springs, Colorado, as public use under the provisions of Title 14 CFR Part 91. No flight plan was on file. The pilot reported no injuries. The local flight originated at Grand Junction-Walker Field (GJT), Grand Junction, Colorado, about 1715, and was returning to GJT when the accident occurred. According to the USDA Safety Manager, the pilot departed GJT on fire assignment as a Forest Service lead airplane, to the Coal Seam Fire in Garfield County, Colorado, in the vicinity of Glenwood Springs. The airplane was operating by request of, and under the control of the Garfield County Sheriffs Department. The pilot reported experiencing low-level wind shear and light, moderate, and severe turbulence from just after takeoff through arriving at the area of operation. Following a reconnaissance of the fire, the pilot reported climbing to approximately 5,000 feet agl (above ground level) to avoid the turbulence and wait for wind conditions to improve so that tanker operations (aircraft dropping fire suppressant chemicals on the wildfire) could begin. The pilot reported that wind conditions improved and tanker operations commenced. On conclusion of the tanker operations, the pilot returned to GJT. The pilot reported he was in the vicinity of the Book Cliffs, approximately 10 miles northeast of GJT, approximately 2,000 feet agl in a low power descent, and an airspeed of approximately 150-160 knots, when he encountered one significant event of severe turbulence. The pilot reported the winds were out of the southwest at 20 knots with gusts to 29 knots. The airplane continued to GJT and landed uneventfully. The aircraft damage was noted the following morning during a routine preflight inspection. An examination of the airplane showed the top skin of the airplane's left wing, between the fuselage and the left engine nacelle, was buckled. Flight control continuity was confirmed. An examination of the engines, engines controls, and other airplane systems revealed no anomalies. At 1956, the Aviation Routine Weather Report for GJT was clear skies, visibility 9 statute miles, temperature 91 degrees Fahrenheit (F), dew point 14 degrees F, winds 180 degrees at 20 knots with gusts to 28 knots, and an altimeter setting of 29.55 inches of Mercury. At 2056, the winds at GJT were reported as 170 degrees at 16 knots with gusts to 24 knots. ## Aircraft - Registration: [N123Z](https://openairdocs.org/deregistered/N123Z-2014-12-16), registration cancelled 2014-12-16, S/N TJ-211, built 1979 (OpenAirDocs) - Reported make and model: Beech 58P - Registry model: [Beech 58P](https://openairdocs.org/model/beech-58p) (registry code 1152744) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: TJ-211 - Engines: Continental TSIO-520-WB 325 horsepower reciprocating; Continental TSIO-520-WB 325 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial observation, Public use - Registered owner: USDA Forest Service - Airworthiness certificate: Standard, Normal - Departed: GJT, Grand Junction, CO - Flight plan: Company VFR - Airport: GJT, Walker Field, runway 29, 10,501 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: none; airline transport, military, commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; last flight review October 1, 2001; seat: left; flight hours: 5,484 total, 1,880 in this make and model, 4,250 as pilot in command, 79 in the last 90 days, 41 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 20 knots, gusting 28 - Visibility: 9 statute miles - Lowest ceiling: none - Temperature: 91 °F, dew point 14 °F - Altimeter: 29.54 inHg - Observed at: GJT, 10 nm away ## Docket (2 files) The files NTSB released with the investigation on October 29, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=54926. 768 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 380 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40164160&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Weather Reports and Records (item 2, .PDF, 389 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40164161&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.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.