# NTSB GAA16CA489: Burkhart Grob Flugzeugbau G109, N909G, Emigrant Gap, CA, September 9, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: September 9, 2016, 14:30 local (21:30 UTC) - Place: Emigrant Gap, CA - Coordinates: 39.281944, -120.711944 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.2819&lon=-120.7119&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of lift](https://openairdocs.org/ntsb-events/500) - 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): 94016 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA16CA489 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94016/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94016 - Page: https://openairdocs.org/ntsb/GAA16CA489 ## Probable cause The pilot's inappropriate decision to continue the flight into higher elevation under high-density altitude conditions, which degraded the glider's climb performance and resulted in impact with trees short of the intended runway. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Burkhart Grob Flugzeugbau G109, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=1660204), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Performance/control parameters: climb rate](https://openairdocs.org/ntsb-findings/01062035): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Burkhart Grob Flugzeugbau G109, 1 case](https://openairdocs.org/ntsb-findings/01062035/cases.md?model=1660204), [All aircraft, 265 cases](https://openairdocs.org/ntsb-findings/01062035/cases.md) - [Temp/humidity/pressure: high density altitude](https://openairdocs.org/ntsb-findings/03031020): Environmental issues › Conditions/weather/phenomena · Decision related to condition; cases with it: [Burkhart Grob Flugzeugbau G109, 1 case](https://openairdocs.org/ntsb-findings/03031020/cases.md?model=1660204), [All aircraft, 278 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Burkhart Grob Flugzeugbau G109, 1 case](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=1660204), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md) - [Temp/humidity/pressure: high density altitude](https://openairdocs.org/ntsb-findings/03031020): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Burkhart Grob Flugzeugbau G109, 1 case](https://openairdocs.org/ntsb-findings/03031020/cases.md?model=1660204), [All aircraft, 278 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Burkhart Grob Flugzeugbau G109, 1 case](https://openairdocs.org/ntsb-events/400/sequence.md?model=1660204), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Enroute: Loss of lift](https://openairdocs.org/ntsb-events/500) (defining event); cases with it: [Burkhart Grob Flugzeugbau G109, 1 case](https://openairdocs.org/ntsb-events/500/sequence.md?model=1660204), [All aircraft, 252 cases](https://openairdocs.org/ntsb-events/500/sequence.md) - [Enroute: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Burkhart Grob Flugzeugbau G109, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=1660204), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot of a powered glider reported that while en-route to his planned destination, he became concerned about the glider's capability, even with the engine operating, to clear rising terrain ahead. The pilot further reported that he was advised by air traffic control that the nearest airport was about 5 nautical miles (NM) ahead and along his route. The pilot decided to continue to this airport, even though lower terrain was available behind him. During the diversion into the higher elevation, the pilot reported that the glider was "low over the terrain" and he determined that he had to make an off-airport landing. Subsequently, the pilot landed the glider into trees about ½ NM from the diversion airport. The right wing and fuselage sustained substantial damage. The pilot reported no preaccident mechanical malfunctions or failures with the powered glider that would have precluded normal operation. About the time of the accident, at the diversion airport, an automated weather observing system reported the wind at 240 degrees true at 7 knots, a temperature of 80 degrees Fahrenheit (27 Celsius), and a dew point of 43 degrees Fahrenheit (6 Celsius). The airport's elevation was 5,283 feet above mean sea level (MSL) and the density altitude was 7,563 feet above MSL. According to the Federal Aviation Administration Koch Chart, the powered glider would have experienced a 62% decrease to the normal rate of climb. The high density altitude likely contributed to the glider's inability to clear the trees en-route to the diversion airport. ## Factual narrative The pilot of a powered glider reported that while en-route to his planned destination, he became concerned about the glider's capability, even with the engine operating, to clear rising terrain ahead. The pilot further reported that he was advised by air traffic control that the nearest airport was about 5 nautical miles (NM) ahead and along his route. The pilot decided to continue to this airport, even though lower terrain was available behind him. During the diversion into the higher elevation, the pilot reported that the glider was "low over the terrain" and he determined that he had to make an off-airport landing. Subsequently, the pilot landed the glider into trees about ½ NM from the diversion airport. The right wing and fuselage sustained substantial damage. The pilot reported no preaccident mechanical malfunctions or failures with the powered glider that would have precluded normal operation. About the time of the accident, at the diversion airport, an automated weather observing system reported the wind at 240 degrees true at 7 knots, a temperature of 80 degrees Fahrenheit (27 Celsius), and a dew point of 43 degrees Fahrenheit (6 Celsius). The airport's elevation was 5,283 feet above mean sea level (MSL) and the density altitude was 7,563 feet above MSL. According to the Federal Aviation Administration Koch Chart, the powered glider would have experienced a 62% decrease to the normal rate of climb. The high density altitude likely contributed to the glider's inability to clear the trees en-route to the diversion airport. ## Aircraft - Registration: [N909G](https://openairdocs.org/deregistered/N909G-2018-06-01), registration cancelled 2018-06-01, S/N 6134, built 1982 (OpenAirDocs) - Reported make and model: BURKHART GROB FLUGZEUGBAU G109 (UNDESIGNAT) - Registry model: [Burkhart Grob Flugzeugbau G109](https://openairdocs.org/model/burkhart-grob-flugzeugbau-g109) (registry code 1660204) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Glider - Serial number: 6134 - Year built: 1982 - Airframe hours: 1095 - Engines: Limbach 2000 reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 2, 2016 - Departed: LHM, LINCOLN, CA - Destination: MEV, MINDEN, NV - Airport: BLU, Blue Canyon - Nyack - Equipment: Handheld GPS, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 73; injuries: none; flight instructor, commercial; last flight review August 21, 2016; seat: left; restraint: 4-point; flight hours: 2,330 total, 796 in this make and model, 2,016 as pilot in command, 13 in the last 90 days, 7 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 43 °F - Altimeter: 30.23 inHg - Observed at: KBLU, 1 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 20160909017919A](https://openairdocs.org/incident/20160909017919A), Sep 9, 2016: Burkhart Grob Flugzeugbau G109, Emigrant Gap, CA, Substantial damage. While in cruise flight a motor glider encountered rising terrain and adverse atmospheric conditions. Pilot was in contact with ATC center and advised of… ## Docket (3 files) The files NTSB released with the investigation on November 7, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94016. 3.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446218&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - NTSB Performance Information (item 2, .PDF, 165 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446219&FileExtension=.PDF&FileName=NTSB%20Performance%20Information-Master.PDF - Accident Photo (Courtesy of Operator) (item 3, .PDF, 1 photo, 81 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446220&FileExtension=.PDF&FileName=Accident%20Photo%20(Courtesy%20of%20Operator)-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.