# NTSB GAA16CA205: Burkhart Grob Flugzeugbau G103 Twin Astir, N40880, Marana, AZ, April 24, 2016 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: April 24, 2016, 14:30 local (21:30 UTC) - Place: Marana, AZ - Coordinates: 32.264999, -111.123611 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.2650&lon=-111.1236&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of lift](https://openairdocs.org/ntsb-events/500) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report July 14, 2016 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: Federal Aviation Administration - NTSB case key (mKey): 93075 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA16CA205 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93075/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93075 - Page: https://openairdocs.org/ntsb/GAA16CA205 ## Probable cause The glider's loss of lift as a result of unfavorable wind conditions for glider operations, consequently resulting in a collision with trees. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Burkhart Grob Flugzeugbau G103 TWIN ASTIR, 1 case](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=1660202), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) - [Wind: downdraft](https://openairdocs.org/ntsb-findings/03034035): Environmental issues › Conditions/weather/phenomena · Effect on equipment; cases with it: [Burkhart Grob Flugzeugbau G103 TWIN ASTIR, 1 case](https://openairdocs.org/ntsb-findings/03034035/cases.md?model=1660202), [All aircraft, 178 cases](https://openairdocs.org/ntsb-findings/03034035/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Burkhart Grob Flugzeugbau G103 TWIN ASTIR, 1 case](https://openairdocs.org/ntsb-events/400/sequence.md?model=1660202), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Maneuvering: Loss of lift](https://openairdocs.org/ntsb-events/500) (defining event); cases with it: [Burkhart Grob Flugzeugbau G103 TWIN ASTIR, 2 cases](https://openairdocs.org/ntsb-events/500/sequence.md?model=1660202), [All aircraft, 252 cases](https://openairdocs.org/ntsb-events/500/sequence.md) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Burkhart Grob Flugzeugbau G103 TWIN ASTIR, 2 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1660202), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis According to the pilot, while maneuvering the glider about 2,900 feet above ground level, the pilot determined that the wind conditions were not conducive to sustain flight and turned toward the runway in order to establish an approach. He recalled that while maneuvering toward the runway, he encountered downdrafts and began to lose altitude rapidly. He reported that he issued a mayday call about ¾ of a statute mile from the runway, established a nose up attitude to decrease the airspeed, and the glider impacted the trees. The glider sustained substantial damage to the right wing and fuselage. The pilot reported that there were no mechanical failures or anomalies with the glider prior to or during the flight that would have prevented normal flight operation. ## Factual narrative According to the pilot, while maneuvering the glider about 2,900 feet above ground level, the pilot determined that the wind conditions were not conducive to sustain flight and turned toward the runway in order to establish an approach. He recalled that while maneuvering toward the runway, he encountered downdrafts and began to lose altitude rapidly. He reported that he issued a mayday call about ¾ of a statute mile from the runway, established a nose up attitude to decrease the airspeed, and the glider impacted the trees. The glider sustained substantial damage to the right wing and fuselage. The pilot reported that there were no mechanical failures or anomalies with the glider prior to or during the flight that would have prevented normal flight operation. ## Aircraft - Registration: [N40880](https://openairdocs.org/deregistered/N40880-2022-10-01), registration cancelled 2022-10-01, S/N 3795, built 1983 (OpenAirDocs) - Reported make and model: BURKHART GROB FLUGZEUGBAU G103 TWIN ASTIR (TWIN II) - Registry model: [Burkhart Grob Flugzeugbau G103 TWIN ASTIR](https://openairdocs.org/model/burkhart-grob-flugzeugbau-g103-twin-astir) (registry code 1660202) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 3795 - Year built: 1983 - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Tucson Soaring Club Inc - Registered owner: Tucson Soaring Club Inc - Airworthiness certificate: Standard, Utility - Last inspection: 100 hour, March 1, 2016, 7,568.8 hours before - Departed: AZ67, TUCSON, AZ - Destination: AZ67, Marana, AZ - Airport: AZ67, El Tiro - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 65; injuries: none; private; airplane ratings: single-engine land; last flight review January 17, 2015; seat: rear; restraint: 4-point; flight hours: 190 total, 42 in this make and model, 181 as pilot in command, 2 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 18 °F - Altimeter: 29.87 inHg - Observed at: KMZJ, 6 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 20160424024999A](https://openairdocs.org/incident/20160424024999A), Apr 24, 2016: Burkhart Grob Flugzeugbau G103 TWIN ASTIR, Tucson, AZ, Substantial damage. Narrative as outlined by pilot, This was the second flight of the day, with one flight ending 30 minutes prior to the flight of this report. Both fights were… ## Docket (2 files) The files NTSB released with the investigation on July 11, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93075. 2.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40442206&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photo (Courtesy of FAA) (item 2, .PDF, 1 photo, 104 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40442207&FileExtension=.PDF&FileName=Photo%20(Courtesy%20of%20FAA)-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.