CEN12LA553

NTSB accident investigation · Schleicher ASG29-15M · Uvalde, TX · August 17, 2012

Accident · Minor injuriesLimited investigationFinal report
Date
August 17, 2012, 15:20 local (20:20 UTC)
Place
Uvalde, TX
Injuries
1 minor, 1 uninjured
Phase of flight
Maneuvering
Aircraft
F-CIFBSchleicher ASG29-15MD-6080Schleicher ASG29-15M
Defining events
Maneuvering: Midair collisionManeuvering: Midair collision
Weather
Visual (VMC) · Day
Status
Completed · report May 9, 2013
Report
Approved by Office Director
NTSB office
Central Region
Parties
FAA Flight Standards District Office
Case key
84717

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

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.

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 · 2

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Schleicher ASG29-15M

Info processing/decision: identification/recognitionPersonnel issues › Action/decision · PilotAll aircraft: 559 casesProbable cause

Schleicher ASG29-15M

Info processing/decision: identification/recognitionPersonnel issues › Action/decision · Pilot of other aircraftAll aircraft: 559 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Schleicher ASG29-15M

Schleicher ASG29-15M

Analysis

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.

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

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.

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 · 2

Registration
F-CIFB
Reported as
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
Registration
D-6080
Reported as
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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot, aircraft 1
Age
33
Injuries
None
Certificates
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
Role
Pilot, aircraft 2
Age
51
Injuries
Minor
Certificates
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

The files NTSB released with the investigation on March 20, 2013, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.2 MB in all.