Aviation Accident Summaries

Aviation Accident Summary DEN08LA137

Brackettville, TX, USA

Aircraft #1

N777UN

Schempp-Hirth Ventus 2A

Aircraft #2

N110RG

AB Sportine Aviacija Genesis 2

Analysis

According to the pilot of N110RG, he was stabilized in a right 55 degree bank and had completed three turns when he heard a loud bang and immediately "lost control." The right wing dropped, the glider rolled to the right, and went inverted. The pilot of N110RG exited the glider and deployed his parachute. During the egress he was seriously injured. According to the pilot of N777UN, he had observed two gliders in the thermal in front of him and entered the thermal underneath them. After two turns in the thermal, he lost sight of the two gliders and collided, shortly thereafter, with N110RG. His left wing and winglet impacted the right wing of the other glider. The pilot of N777UN landed uneventfully. N110RG was destroyed and N777UN sustained minor damage. The damage to the right wing, sustained during the collision, rendered N110RG uncontrollable. Soaring procedure recommend that the pilot exit a thermal if visual contact is lost with another glider and cannot be established via a radio call.

Factual Information

On August 9, 2008, at 1532 central daylight time, a Schempp-Hirth Ventus 2A glider, N777UN, collided with an AB Sportine Aviacija Genesis 2 glider, N110RG, during a sailplane race six miles north of Brackettville, Texas. Visual meteorological conditions prevailed at the time of the accident. The local flights were being conducted under the provisions of Title 14 Code of Federal Regulations Part 91 without flight plans. The pilot of N777UN was uninjured, while the pilot of N110RG sustained serious injuries. Both flights departed Garner Field Airport (UVA), Uvalde, Texas, approximately 1300. The gliders involved in this midair collision were competing in the Soaring Society of America, 15 meter class National Sailplane Race. According to a telephone conversation with and subsequent accident report form submitted by the pilot of N110RG, he was following behind another glider at an altitude of 5,000 feet, heading for the first turn point in the competition. The glider in front of him entered a thermal and the pilot of N110RG established visual contact with the other pilot before entering the thermal behind him. He stabilized a right 55 degree bank and had completed three turns when he heard a loud bang and immediately "lost control." The right wing dropped, the glider rolled to the right, and went inverted. The pilot of N110RG exited the glider and deployed his parachute. During the egress, he was struck in the neck by some portion of the glider. The parachute deployed without issue; however, the landing was hard, resulting in serious injuries. According to the Federal Aviation Administration (FAA) inspector who traveled to the accident, N110RG impacted terrain six miles north of Brackettville. The glider wreckage was inverted and exhibited signatures of a "right hand spin" prior to impact. A "heavy rub mark and gash" was noted on the bottom side of the right wing. The gash transitioned into a tear and partial separation of fiberglass. Material and paint transfer in the gash were consistent with the winglet of N777UN. The inspector stated that this damage would have inhibited the use of the right aileron and spoileron. According to a telephone conversation with and subsequent accident report form submitted by the pilot of N777UN, he had observed two gliders in the thermal in front of him and entered the thermal underneath them. After two turns in the thermal, he lost sight of the two gliders and collided, shortly thereafter, with N110RG. His left wing and winglet impacted the right wing of the other glider. The pilot of N777UN landed uneventfully at UVA. The FAA inspector reported that the winglet on N777UN was swept back 45 degrees. Material and paint transfer in the winglet were consistent with the surface area of the wing of N110RG. According to the FAA Glider Flying Handbook - Chapter 10, Soaring Techniques, it is recommended that if the pilot looses sight of another glider in a thermal and cannot establish position via radio contact, "leave the thermal." Radio procedures during a soaring competition are not permitted.

Probable Cause and Findings

The failure of the pilot of N777UN to exit the thermal upon losing visual contact with the other gliders, resulting in a midair collision.

 

Source: NTSB Aviation Accident Database

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