# NTSB GAA16CA479: Schleicher ASW 27, N27BZ, Benton, TN, September 4, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: September 4, 2016, 13:45 local (17:45 UTC) - Place: Benton, TN - Coordinates: 35.115833, -84.355003 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.1158&lon=-84.3550&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Hard landing](https://openairdocs.org/ntsb-events/092) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 15, 2016 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 93999 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA16CA479 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93999/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93999 - Page: https://openairdocs.org/ntsb/GAA16CA479 ## Probable cause The glider pilot's descent below the glidepath and the subsequent hard, off-airport landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: glide](https://openairdocs.org/ntsb-findings/01062027): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Schleicher ASW-27, 1 case](https://openairdocs.org/ntsb-findings/01062027/cases.md?model=3801501), [All aircraft, 7 cases](https://openairdocs.org/ntsb-findings/01062027/cases.md) - [Attention/monitoring: task monitoring/vigilance](https://openairdocs.org/ntsb-findings/02021520): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Schleicher ASW-27, 1 case](https://openairdocs.org/ntsb-findings/02021520/cases.md?model=3801501), [All aircraft, 330 cases](https://openairdocs.org/ntsb-findings/02021520/cases.md) - [Environmental issues](https://openairdocs.org/ntsb-findings/03030000): Environmental issues › Conditions/weather/phenomena · Effect on equipment; cases with it: [Schleicher ASW-27, 2 cases](https://openairdocs.org/ntsb-findings/03030000/cases.md?model=3801501), [All aircraft, 57 cases](https://openairdocs.org/ntsb-findings/03030000/cases.md) - [Planning/preparation: weather planning](https://openairdocs.org/ntsb-findings/02061020): Personnel issues › Task performance · Pilot; cases with it: [Schleicher ASW-27, 2 cases](https://openairdocs.org/ntsb-findings/02061020/cases.md?model=3801501), [All aircraft, 156 cases](https://openairdocs.org/ntsb-findings/02061020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Loss of lift](https://openairdocs.org/ntsb-events/500); cases with it: [Schleicher ASW-27, 5 cases](https://openairdocs.org/ntsb-events/500/sequence.md?model=3801501), [All aircraft, 252 cases](https://openairdocs.org/ntsb-events/500/sequence.md) - [Landing: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Schleicher ASW-27, 1 case](https://openairdocs.org/ntsb-events/060/sequence.md?model=3801501), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Schleicher ASW-27, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=3801501), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis According to the pilot of the glider, he released from the tow airplane at 2,000 feet above ground level and turned to the south toward a ridge in search of orographic lift. The pilot reported that he found "weak lift" in the vicinity of the ridge and when he reached the south end of the ridge, he turned back to the departure airport because he could not maintain altitude. The pilot recalled that while in route back to the airport, he encountered sink, descended below the glide path to the airport and initiated an off airport landing to a large field. The pilot reported that during approach, he over flew a set of powerlines that were perpendicular to his glide path and noticed a second set of powerlines ahead that were also perpendicular to his glide path. The pilot recalled that he turned to avoid the powerlines, encountered more sink, leveled the wings and landed hard in the field. The glider sustained substantial damage to the tailboom. The pilot reported that there were no mechanical malfunctions or anomalies during the flight that would have prevented normal flight operations. ## Factual narrative According to the pilot of the glider, he released from the tow airplane at 2,000 feet above ground level and turned to the south toward a ridge in search of orographic lift. The pilot reported that he found "weak lift" in the vicinity of the ridge and when he reached the south end of the ridge, he turned back to the departure airport because he could not maintain altitude. The pilot recalled that while in route back to the airport, he encountered sink, descended below the glide path to the airport and initiated an off airport landing to a large field. The pilot reported that during approach, he over flew a set of powerlines that were perpendicular to his glide path and noticed a second set of powerlines ahead that were also perpendicular to his glide path. The pilot recalled that he turned to avoid the powerlines, encountered more sink, leveled the wings and landed hard in the field. The glider sustained substantial damage to the tailboom. The pilot reported that there were no mechanical malfunctions or anomalies during the flight that would have prevented normal flight operations. ## Aircraft - Registration: [N27BZ](https://openairdocs.org/aircraft/N27BZ), registered now, S/N 27213, built 2003 (OpenAirDocs) - Reported make and model: SCHLEICHER ASW 27 (NO SERIES) - Registry model: [Schleicher ASW-27](https://openairdocs.org/model/schleicher-asw-27) (registry code 3801501) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 27002 - Year built: 1995 - Airframe hours: 1295 - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Mittell Aviation LLC - Registered owner: Mittell Aviation LLC - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, April 6, 2016 - Departed: 92A, Benton, TN - Destination: 92A, Benton, TN - Airport: 92A, Chilhowee, runway 03, 2,600 × 200 ft, grass/turf - Equipment: Electronic multifunction display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; injuries: none; private; last flight review January 30, 2016; seat: single; restraint: 4-point; flight hours: 5,000 total, 950 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Altimeter: 30.21 inHg - Observed at: KDZJ, 25 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 20160904023869A](https://openairdocs.org/incident/20160904023869A), Sep 4, 2016: Schleicher ASW-27, Benton, TN, Substantial damage. Aircraft was towed and released at approximately 2000 feet and then proceeded to fly 6 to 7 miles from the departing airport. The aircraft encountered several… ## Docket (2 files) The files NTSB released with the investigation on November 18, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93999. 2.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446632&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photo (item 2, .PDF, 262 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446633&FileExtension=.PDF&FileName=Photo-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.