# NTSB CEN12LA553: Schleicher ASG29-15M, Uvalde, TX, August 17, 2012 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: August 17, 2012, 15:20 local (20:20 UTC) - Place: Uvalde, TX - Coordinates: 29.113611, -99.944999 - Nearby events: https://openairdocs.org/map.md?lat=29.1136&lon=-99.9450&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining events: [Maneuvering: Midair collision](https://openairdocs.org/ntsb-events/250); [Maneuvering: Midair collision](https://openairdocs.org/ntsb-events/250) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report May 9, 2013 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 84717 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12LA553 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84717/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84717 - Page: https://openairdocs.org/ntsb/CEN12LA553 ## Probable cause (aircraft 1) The glider pilot’s inadequate visual lookout and collision avoidance just after joining a thermal in which other gliders were operating, which resulted in a midair collision with another glider. ## Probable cause (aircraft 2) Inadequate visual lookout and collision avoidance by another glider pilot, who had just joined a thermal in which other gliders were operating, which resulted in a midair collision with the glider. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · Pilot (probable cause), aircraft 1; cases with it: [All aircraft, 559 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md) - [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · Pilot of other aircraft (probable cause), aircraft 2; cases with it: [All aircraft, 559 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Midair collision](https://openairdocs.org/ntsb-events/250) (defining event), aircraft 1; cases with it: [All aircraft, 196 cases](https://openairdocs.org/ntsb-events/250/sequence.md) - [Maneuvering: Midair collision](https://openairdocs.org/ntsb-events/250) (defining event), aircraft 2; cases with it: [All aircraft, 196 cases](https://openairdocs.org/ntsb-events/250/sequence.md) ## Analysis (aircraft 1) The pilots of both gliders were engaged in an international gliding competition. The pilot of F-CIFB said he was circling at an altitude of about 6,000 feet mean sea level (msl) when he observed that the pilot of D-6080 was operating in a good “bubble” (thermal) about 325 feet below him. The pilot of F-CIFB maneuvered his glider into the same “bubble” behind D-6080. Shortly thereafter, he heard his glider’s proximity alarm sound "BELOW" and felt an impact. The pilot of D-6080 said he was climbing with several other gliders in a strong thermal when he was struck by F-CIFB from behind. He said he did not see the glider and was unaware of its presence. The collision occurred about 5,700 feet msl. The pilot of D-6080 parachuted to safety. The pilot of F-CIFB landed the glider uneventfully with minor damage to its left wing. The empennage of D-6080 was severed and later found some distance from the main wreckage. Damage was consistent with D-6080 being struck from below and behind by F-CIFB. ## Analysis (aircraft 2) The pilots of both gliders were engaged in an international gliding competition. The pilot of F-CIFB said he was circling at an altitude of about 6,000 feet mean sea level (msl) when he observed that the pilot of D-6080 was operating in a good “bubble” (thermal) about 325 feet below him. The pilot of F-CIFB maneuvered his glider into the same “bubble” behind D-6080. Shortly thereafter, he heard his glider’s proximity alarm sound "BELOW" and felt an impact. The pilot of D-6080 said he was climbing with several other gliders in a strong thermal when he was struck by F-CIFB from behind. He said he did not see the glider and was unaware of its presence. The collision occurred about 5,700 feet msl. The pilot of D-6080 parachuted to safety. The pilot of F-CIFB landed the glider uneventfully with minor damage to its left wing. The empennage of D-6080 was severed and later found some distance from the main wreckage. Damage was consistent with D-6080 being struck from below and behind by F-CIFB. ## Factual narrative (aircraft 1) On August 17, 2012, about 1520 central daylight time, a Schleicher ASG29-15M, French registration F-CIFB, collided in midair with another Schleicher ASG29-15M, German registration D-6080, about 18 miles southwest of Garner Field (KUVA), Uvalde, Texas. The pilot of F-CIFB was not injured. The glider sustained minor damage. The pilot of D-6080 sustained minor injuries. The glider was substantially damaged. Both gliders were registered to and operated by their respective pilots under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed at the time of the accident, and no flight plans had been filed. The local flights originated from KUVA approximately 1330. Both pilots were competing in the 15-meter class of the 32nd World Gliding Championship. According to the pilot of F-CIFB, he was circling about 30 kilometers (18 miles) west-southwest of Uvalde at an altitude of 1,800 to 1,900 meters (5,906 to 6,234 feet). He said D-6080 was about 100 meters (328 feet) below him in a thermal. He said one turn later, D-6080 was about 20 meters (66 feet) below him. He noted that D-6080 was in a good "bubble" (thermal), so he maneuvered his glider into the same bubble. He said he was about 100-150 meters (328 to 492 feet) behind D-6080. As he was about to complete a thermal turn, he heard the proximity alarm sound "BELOW," and felt a strong impact. He saw D-6080 falling in two pieces: the tail, and the wings and canopy. He observed the pilot bail out. At about this time, water from the ballast came into his cockpit. He returned to KUVA and landed uneventfully. According to the pilot of D-6080, he was climbing with several other gliders in a strong thermal when he was struck from behind by F-CIFB. He said he did not see the glider and was unaware of its presence. The collision occurred about 5,700 feet msl (above mean sea level). D-6080 pitched over inverted when the collision severed its tail assembly. The pilot jettisoned the canopy, exited the glider at about 4,000 feet agl (above ground level), and parachuted to safety. He watched his glider as it spiraled down. He landed in a rough field and was rescued about 90 minutes later. A Federal Aviation Administration inspector from the San Antonio Flight Standards District Office responded to the accident site. He observed that the empennage of D-6080 had been severed and was located some distance from the main body of wreckage. Collision signatures on both gliders were consistent with D-6080 being struck from below and behind by F-CIFB. His examination of F-CIFB revealed minor damage to its left wing. According to FAA's "Glider Flying Handbook," collision avoidance is of primary importance when thermalling with other gliders. All gliders in a particular thermal should circle in the same direction. The first glider in a thermal should establish the direction of turn and all other gliders joining the thermal should turn in the same direction. Two gliders in the samethermal at the same height or nearly so should position themselves across from each other so they can best maintain visual contact. A glider entering a thermal should not interfere with other gliders already in the thermal and not cause a hazard to other gliders. ## Factual narrative (aircraft 2) On August 17, 2012, about 1520 central daylight time, a Schleicher ASG29-15M, French registration F-CIFB, collided in midair with another Schleicher ASG29-15M, German registration D-6080, about 18 miles southwest of Garner Field (KUVA), Uvalde, Texas. The pilot of F-CIFB was not injured. The glider sustained minor damage. The pilot of D-6080 sustained minor injuries. The glider was substantially damaged. Both gliders were registered to and operated by their respective pilots under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed at the time of the accident, and no flight plans had been filed. The local flights originated from KUVA approximately 1330. Both pilots were competing in the 15-meter class of the 32nd World Gliding Championship. According to the pilot of F-CIFB, he was circling about 30 kilometers (18 miles) west-southwest of Uvalde at an altitude of 1,800 to 1,900 meters (5,906 to 6,234 feet). He said D-6080 was about 100 meters (328 feet) below him in a thermal. He said one turn later, D-6080 was about 20 meters (66 feet) below him. He noted that D-6080 was in a good "bubble" (thermal), so he maneuvered his glider into the same bubble. He said he was about 100-150 meters (328 to 492 feet) behind D-6080. As he was about to complete a thermal turn, he heard the proximity alarm sound "BELOW," and felt a strong impact. He saw D-6080 falling in two pieces: the tail, and the wings and canopy. He observed the pilot bail out. At about this time, water from the ballast came into his cockpit. He returned to KUVA and landed uneventfully. According to the pilot of D-6080, he was climbing with several other gliders in a strong thermal when he was struck from behind by F-CIFB. He said he did not see the glider and was unaware of its presence. The collision occurred about 5,700 feet msl (above mean sea level). D-6080 pitched over inverted when the collision severed its tail assembly. The pilot jettisoned the canopy, exited the glider at about 4,000 feet agl (above ground level), and parachuted to safety. He watched his glider as it spiraled down. He landed in a rough field and was rescued about 90 minutes later. A Federal Aviation Administration inspector from the San Antonio Flight Standards District Office responded to the accident site. He observed that the empennage of D-6080 had been severed and was located some distance from the main body of wreckage. Collision signatures on both gliders were consistent with D-6080 being struck from below and behind by F-CIFB. His examination of F-CIFB revealed minor damage to its left wing. According to FAA's "Glider Flying Handbook," collision avoidance is of primary importance when thermalling with other gliders. All gliders in a particular thermal should circle in the same direction. The first glider in a thermal should establish the direction of turn and all other gliders joining the thermal should turn in the same direction. Two gliders in the samethermal at the same height or nearly so should position themselves across from each other so they can best maintain visual contact. A glider entering a thermal should not interfere with other gliders already in the thermal and not cause a hazard to other gliders. ## Aircraft 1 - Registration: F-CIFB (not matched to a registry record) - Reported make and model: SCHLEICHER ASG29-15M - Category: Glider - Serial number: 29066 - Airframe hours: 150 - Damage: Minor damage - Flight: Air race/show, Part 91 - Operator: Louis Bouderlique - Registered owner: Federatio Francaise de Vol A Voile (FFVV) - Airworthiness certificate: Standard, Utility - Last inspection: Annual, March 10, 2012 - Departed: KUVA, Uvalde, TX - Destination: KUVA, Uvalde, TX - Airport: KUVA, Garner Field ## Aircraft 2 - Registration: D-6080 (not matched to a registry record) - Reported make and model: SCHLEICHER ASG29-15M - Category: Glider - Serial number: 29641 - Damage: Substantial damage - Flight: Air race/show, Part 91 - Operator: Peter Hartmann - Registered owner: Peter Hartmann - Airworthiness certificate: Standard, Utility - Departed: KUVA, Uvalde, TX - Destination: KUVA, Uvalde, TX - Airport: KUVA, Garner Field ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot, aircraft 1; age 33; injuries: none; airline transport, private; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review March 18, 2012; seat: single; flight hours: 6,000 total, 250 in the last 90 days - Pilot, aircraft 2; age 51; injuries: minor; private, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; seat: single; flight hours: 13,000 total, 3,500 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 5 knots, gusting 16 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 99 °F, dew point 63 °F - Altimeter: 29.90 inHg - Observed at: KUVA, 19 nm away ## Docket (6 files) The files NTSB released with the investigation on March 20, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84717. 1.2 MB in all. - NTSB Form 6120.1-2, Pilot-Operator Aircraft Accident Report (item 1, .PDF, 556 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40383994&FileExtension=.PDF&FileName=NTSB%20Form%206120.1-2,%20Pilot-Operator%20Aircraft%20Accident%20Report-Redacted.PDF - E-Mail from FAA Inspector (item 2, .PDF, 14 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40385198&FileExtension=.PDF&FileName=E-Mail%20from%20FAA%20Inspector-Redacted.PDF - Louis Bouderlique's Statement (item 3, .PDF, 421 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384035&FileExtension=.PDF&FileName=Louis%20Bouderlique%27s%20Statement-Master.PDF - Peter Hartmann's Statement (item 4, .PDF, 13 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40385496&FileExtension=.PDF&FileName=Peter%20Hartmann%27s%20Statement-Redacted.PDF - Weather Reports and Records (item 5, .PDF, 49 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40383432&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.PDF - Excerpt from FAA's Glider Flying Handbook, H-8083-13 (item 6, .PDF, 175 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40385506&FileExtension=.PDF&FileName=Excerpt%20from%20FAA%27s%20Glider%20Flying%20Handbook,%20H-8083-13-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.