# NTSB IAD02LA059: Schleicher ASK21, N341KS, Woodstock, VA, June 16, 2002 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 16, 2002, 15:45 local (19:45 UTC) - Place: Woodstock, VA - Coordinates: 38.883335, -78.502777 - Nearby events: https://openairdocs.org/map.md?lat=38.8833&lon=-78.5028&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report August 26, 2003 - Report: Approved by Office Director - Parties: FAA/FSDO - NTSB case key (mKey): 54984 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=IAD02LA059 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/54984/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=54984 - Page: https://openairdocs.org/ntsb/IAD02LA059 ## Probable cause The pilot's failure to recognize the loss of orographic lift conditions. A factor was the loss of orographic lift. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, maneuvering - weather condition - other (contributing factor) - weather evaluation - inadequate, pilot in command (cause) - stall/mush - inadvertent, pilot in command - In flight collision with object, maneuvering - object - tree(s) ## Analysis After being released from the tow plane, the pilot flew the glider for about 10 miles along a ridge. According to the pilot, he failed to recognize that the wind speed necessary to generate sufficient orographic lift had diminished, and also failed to execute a turn toward the valley while he had sufficient altitude to clear the terrain. As he executed a turn "into very weak ridge lift," the glider stalled, and mushed into trees. The pilot reported that his evaluation of the weather conditions prior to his departure predicted "good orographic lift" in the area. He also reported no mechanical deficiencies with the glider. ## Factual narrative On June 16, 2002, about 1545 eastern daylight time, a Schleicher ASK21 glider, N341KS, was substantially damaged when it impacted trees, then terrain, while maneuvering near Woodstock, Virginia. The certificated commercial pilot and the passenger received minor injuries. Visual meteorological conditions prevailed and no flight plan was filed for the flight that departed the Front Royal-Warren County Airport (FRR), Front Royal, Virginia. The local personal flight was conducted under 14 CFR Part 91. After he departed behind a tow airplane about 1530, the pilot flew toward the Massanutten Ridge. The glider was released from the tow airplane in the vicinity of Signal Knob, and flew about 10 miles along the ridge. In a written statement, the pilot reported that while he was ridge soaring along Massanutten mountain, he "failed to recognize that the wind speed necessary to generate sufficient orographic lift had diminished." He also stated that he "failed to execute an alternate plan of turning toward the Shenandoah Valley, while he had enough altitude above the trees to safely make the turn." The pilot reported that when he attempted to make the turn toward the valley, "into very weak ridge lift," the glider stalled and "mushed" into the trees. The glider slid through the trees, then impacted the ground in a nose low attitude. The pilot also stated that he evaluated the weather conditions prior to his departure by visual observation, and talking to other pilots. He noted there was an overcast cloud layer about 4,000 feet, and the shadows from the clouds demonstrated there was "good orographic lift" in the area. The winds at the surface were from 270 degrees at 10 knots, and at the ridge top they were from 270 degrees about 15-20 knots. The pilot reported approximately 445 hours of total flight experience, 186 of which, were in make and model. He also reported no mechanical deficiencies with the glider. According to the pilot, the glider sustained substantial damage to both wings, the fuselage, and the horizontal stabilizer. Weather reported at Winchester Regional Airport (OKV), Winchester, Virginia, 24 miles to the northeast, at 1540, included wind from 280 degrees at 12 knots, gusting to 17 knots, 10 miles visibility, and clear skies. ## Aircraft - Registration: [N341KS](https://openairdocs.org/deregistered/N341KS-2002-08-08), registration cancelled 2002-08-08, S/N 21252, built 1985 (OpenAirDocs) - Reported make and model: Schleicher ASK21 - Registry model: [Schleicher ASK-21](https://openairdocs.org/model/schleicher-ask-21) (registry code 38015GY) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 21252 - Airframe hours: 2860 - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Frederic Winter - Registered owner: The K-21 Group - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 1, 2002, 60 hours before - Departed: FRR, Front Royal, VA - Destination: FRR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; injuries: minor; commercial; last flight review April 7, 2001; seat: rear; flight hours: 420 total, 186 in this make and model, 365 as pilot in command, 2 in the last 90 days, 2 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 280° at 12 knots, gusting 17 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 57 °F - Altimeter: 29.78 inHg - Observed at: OKV, 24 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 20020616017729A](https://openairdocs.org/incident/20020616017729A), Jun 16, 2002: Schler ASK21, Woodstock, VA, No damage. (-23) Pilot stated that he was ridge flying, lost lift, made decision too late to try to find a place to land. While trying to make a turn back to the ridge… ## Docket (3 files) The files NTSB released with the investigation on June 24, 2003, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=54984. 1.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446104&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot Statement (item 2, .PDF, 66 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40179943&FileExtension=.PDF&FileName=Pilot%20Statement-Master.PDF - Pilot Summary of Interview (item 3, .PDF, 50 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40179944&FileExtension=.PDF&FileName=Pilot%20Summary%20of%20Interview-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.