# NTSB ATL02LA027: Flugzeugbau DG-200, N5457T, Benton, TN, December 29, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: December 29, 2001, 15:00 local (20:00 UTC) - Place: Benton, TN - Coordinates: 35.226387, -84.584724 - Nearby events: https://openairdocs.org/map.md?lat=35.2264&lon=-84.5847&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 29, 2003 - Report: Approved by Office Director - Parties: FAA Nashville FSDO-03 - NTSB case key (mKey): 53962 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL02LA027 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/53962/pdf - Page: https://openairdocs.org/ntsb/ATL02LA027 ## Probable cause The pilot's inadvertent encounter with a downdraft while maneuvering in a ridge lift during a turn resulting in an in-flight collision with trees. ## Analysis The glider pilot was flying north in a ridge lift about 400 feet above a plateau area where he had previously found good thermals. He started a turn towards the front of the ridge towards a valley and encountered a severe sink rate. He continued the turn and the sink rate increased between 1,500 to 3,000 feet per minute and the glider collided with trees. The pilot did not experienced a mechanical failure or malfunction of the airframe or flight control system. ## Factual narrative On December 29, 2001, at about 1500 eastern standard time, a Glaser-Dirks Flugzeugbau DG-200,glider, N5457T, registered to a private owner, operating as a 14 CFR Part 91 personal flight collided with trees while maneuvering in the vicinity of Benton, Tennessee, following the loss of thermal lifting. Visual meteorological conditions prevailed and no flight plan was filed. The glider sustained substantial damage. The private pilot reported minor injuries. The flight originated from Chilhowee Glider Port, Benton, Tennessee, at 1300. The pilot stated he was flying north in a ridge lift. He turned back over a plateau area where he had previously encountered good thermals. He looked at his airspeed indicator before turning and it indicated 90 knots. He continued his turn toward the front of the ridge toward the valley and encountered a severe sink rate about 180-degrees into the turn. The vertical speed indicator went from a climb to a 1,300 foot per minute descent. According to the pilot, the glider was about 400 feet above ground level which under normal circumstances should have been enough altitude to clear the ridgeline. As he continued the turn, the sink rate increased between 1,500 feet per minute to 3,000 feet per minute. The glider descended into trees short of the ridgeline. The pilot further stated he did not experience any mechanical failure or malfunction of the airframe or flight control system. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, maneuvering - weather condition - downdraft (cause) - In flight collision with object, maneuvering - object - tree(s) ## Aircraft - Registration: [N5457T](https://openairdocs.org/deregistered/N5457T-2002-03-05), registration cancelled 2002-03-05, S/N 2-57A, built 1978 (OpenAirDocs) - Reported make and model: Flugzeugbau DG-200 - Registry model: [Glaser-Dirks Flugzeugbau DG-200](https://openairdocs.org/model/glaser-dirks-flugzeugbau-dg-200) (registry code 3802506) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 2-57A - Airframe hours: 1207 - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Christopher J. Ruf - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, March 23, 2001, 79 hours before - Departed: 92A, Benton, TN ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; injuries: none; private; last flight review July 22, 2000; seat: front; flight hours: 422 total, 204 in this make and model, 386 as pilot in command, 17 in the last 90 days, 2 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 10 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 48 °F, dew point 43 °F - Altimeter: 29.98 inHg - Observed at: CHA, 166 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 20011229035339A](https://openairdocs.org/incident/20011229035339A), Dec 29, 2001: Glaser DG200, Benton, TN, Substantial damage. (.19) On December 29, 20001, at about 1500 eastern standard time, a Glaser-dirks flugzeugbau DG-200, N5457T, registered to a private owner, operating as a 14… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; 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.