Aviation Accident Summaries

Aviation Accident Summary CEN10LA459

Batesville, TX, USA

Aircraft #1

N7470C

SCHEMPP-HIRTH VENTUS-2B

Aircraft #2

N8829A

ALEXANDER SCHLEICHER GMBH & CO ASW 27-18

Analysis

While participating in a soaring competition, a Schempp-Hirth glider and an Alexander Schleicher glider collided while in flight. The Schempp-Hirth glider was outbound from the last way point for the competition course and the Alexander Schleicher glider was inbound to this same point. The courses inbound and outbound from this way point are near reciprocals of one another. According to the pilot of the Alexander Schleicher glider and the damage to both gliders, the empennage and tailwheel of the Schempp-Hirth glider impacted the right horizontal stabilizer and elevator of the Alexander Schleicher glider. The speed, altitude, and course of each glider would not have allowed enough time for either pilot to see the other glider and react with enough time to avoid a collision. An examination of the airframe and related systems of both gliders revealed no anomalies.

Factual Information

**This report was modified on 7-13-2011. Please see the public docket for this accident for details of the changes made.** HISTORY OF FLIGHT On August 4, 2010, approximately 1820 central daylight time, N7470C, a Schempp-Hirth Ventus-2B glider, collided with N8829A, an Alexander Schleicher GmbH & Company ASW 27-18 glider, while both were competing in a soaring competition near Batesville, Texas. Both gliders were substantially damaged. Visual meteorological conditions prevailed at the time of the accident. Both flights were being conducted under the provisions of 14 Code of Federal Regulations Part 91 without flight plans. The commercial glider pilot on board the Schempp-Hirth glider was fatally injured. The private glider pilot on board the Alexander Schleicher glider was not injured. Both gliders were air towed from Garner Field Airport (KUVA), Uvalde, Texas. The two gliders were participating in a soaring competition; there were approximately 28 gliders competing. Both gliders had departed KUVA between 1255 and 1310 the day of the accident. The course consisted of five legs. Leg one departed KUVA and proceeded south southeast to Callagan. Leg two reversed course at Callagan and proceeded to the northeast towards Uno Mas road. Leg three reversed course at Uno Mas road and proceeded north northwest to Leakey. Leg four reversed course at Leakey and proceeded south to Batesville. The fifth and final leg reversed course again, nearly 180 degrees, and proceeded back to KUVA. According to a written statement, and subsequent verbal statements provided by the pilot of the Alexander Schleicher glider, he was en route from turn point Leakey to turn point Batesville (leg four), in straight and level flight, at an approximate altitude of 4,000 feet, and an estimated speed of 100 knots. The pilot of the Alexander Schleicher glider observed several gliders who he assumed were en route to KUVA. He did not observe the Schempp-Hirth glider until the gear door appeared over his glider. The Schempp-Hirth glider passed over the top of his glider canopy, flying in the opposite direction, and impacted the tail of his glider. The pilot of the Alexander Schleicher glider was able to continue flying the glider and landed without further incident in a nearby field, north of Batesville. According to a Federal Aviation Administration (FAA) inspector who assisted in the investigation, the Schempp-Hirth glider was between 3,000 and 4,000 feet at an estimated speed of 100 to 150 knots. The FAA reported that the Schempp-Hirth glider had completed the final turn at Batesville and was northbound at the time of the collision. A participant in the soaring competition observed the Schempp-Hirth glider after the collision. He noted that the empennage was broken and that only a portion of the empennage remained attached through control cables. He stated that he observed the Schempp-Hirth glider spin twice. The Schempp-Hirth glider impacted terrain in a nose low attitude. PERSONNEL INFORMATION Schempp-Hirth Pilot The Schempp-Hirth glider pilot, age 51, held a commercial pilot certificate with a glider rating. He held a third class medical certificate issued on February 23, 2009. The certificate contained the limitation "must wear corrective lenses." According to the Schempp-Hirth glider pilot's family, he successfully completed the requirements of a flight review on August 29, 2009. The family was unable to locate his flight log; however, they estimated his total flight time as over 6,000 hours. He had previous experience competing in soaring events. Alexander Schleicher Pilot The Alexander Schleicher glider pilot, age 54, held a private pilot certificate with glider and airplane single engine land ratings. He did not hold, nor was he required to hold, a medical certificate. The Alexander Schleicher glider pilot indicated he had logged approximately 1,000 hours of total flight time; 23 of which were logged in the make and model of the accident glider. He successfully completed the requirements of a flight review on May 7, 2010. He had previous experience competing in soaring events. AIRCRAFT INFORMATION Schempp-Hirth The Schempp-Hirth Ventus-2B glider (serial number 150), was manufactured in 2003. It was registered with the FAA on an experimental airworthiness certificate for exhibition and air racing purposes. The glider was registered to and operated by the pilot, and was maintained under a condition inspection program. A review of the maintenance records indicated that a condition inspection had been completed on July 4, 2009, at an airframe total time of 623.32 hours. Alexander Schleicher The Alexander Schleicher GmbH & Company ASW 27-18 glider (serial number 29034), was manufactured in 2008. It was registered with the FAA on an experimental airworthiness certificate for exhibition and air racing operations. The glider was registered to an individual, operated by the pilot, and was maintained under an annual inspection program. The pilot reported that an annual inspection had been completed on March 12, 2010. The glider had a total airframe time of 208 hours at the time of the accident. METEOROLOGICAL INFORMATION The closest official weather observation station was Hondo Municipal Airport (KHDO), Hondo, Texas, located 31 nautical miles (nm) east of the accident site. The elevation of the weather observation station was 930 feet mean sea level. The routine aviation weather report (METAR) for KHDO, issued at 1751, reported winds 140 degrees at 12 knots, gusting to 17 knots, visibility 10 miles, sky condition clouds broken at 7,000 feet, temperature 37 degrees Celsius (C), dew point 20 degrees C, altimeter 29.95 inches. FLIGHT RECORDERS The Alexander Schleicher glider was equipped with an EW Avionics microreader which is a GPS-based flight recorder. The unit was sent to the National Transportation Safety Board (NTSB) Vehicle Recorders Lab in Washington, D.C., for download. The FLASH memory device was read out from the SD card for extraction of flight data associated with this accident. Downloaded data included date, time, latitude, longitude, pressure altitude, GPS altitude, fix validity, and fix accuracy. The Schempp-Hirth glider was equipped with multiple recording devices. While on scene, the FAA secured two data logger units, and sent them to the NTSB Vehicle Recorders Lab in Washington, D.C., for download. The units were sent utilizing the United Parcel Service of America (UPS) overnight service; however, the units never arrived in Washington, D.C., and were never located by UPS. In January of 2011, the NTSB investigator-in-charge removed the remaining instrumentation, two Cambridge Aero Instruments Model 303 units, from the glider and sent them to the NTSB Vehicle Recorders Lab in Washington D.C. for download. No accident data was recovered from either unit. WRECKAGE AND IMPACT INFORMATION The wreckage of the Schempp-Hirth glider was located in level terrain vegetated with tall grass and five to six foot tall brush. The glider came to rest inverted, was fragmented, and the debris extended approximately 1,000 feet from the main wreckage. The Alexander Schleicher glider performed a forced landing to a plowed field. MEDICAL AND PATHOLOGICAL INFORMATION The autopsy was performed, on the pilot of the Schempp-Hirth glider, by the Bexar County Medical Examiner's Office on August 5, 2011. The autopsy concluded that the cause of death was due to multiple blunt force injuries. Toxicological tests were performed on specimens that were collected during the autopsy. Results were negative for all tests conducted. ADDITIONAL INFORMATION Schempp-Hirth Examination The wreckage of the Schempp-Hirth glider was recovered and relocated to a storage facility in Lancaster, Texas. The examination was conducted by an NTSB investigator on September 28, 2010. The cabin and forward fuselage of the glider were fragmented. Dirt and grass was embedded in the fiberglass of the forward fuselage. The canopy was fragmented. The left wing included the left flap, left spoiler, and left aileron. The left spoiler was in the deployed position and was bent forward. The left flap was unremarkable and in the retracted position. The left aileron separated from the wing and was fragmented. The wing was crushed and broken. Control continuity to the left aileron, spoiler, and flap was confirmed. The right wing included the right flap, right spoiler, and right aileron. The wing was broken into at least four large sections. The right spoiler was deployed and bent rearward. The right flap was broken upward and aft at midspan. The right aileron remained partially attached to the wing and was fractured at midspan. Control continuity to the right aileron, spoiler, and flap was confirmed. The empennage included the vertical and horizontal stabilizer, elevator, and rudder, and was separated from the aft fuselage. The elevator was intact and free of damage. The very bottom and aft portion of the empennage was crushed and fragmented. Control continuity to the rudder and elevator was confirmed. Alexander Schleicher Examination The airframe and systems of the Alexander Schleicher glider were examined by FAA inspectors while they were on scene. The right side of the horizontal stabilizer and elevator separated. A diagonal witness mark approximately 1.5 inches wide and 4 to 6 inches in length was noted on the right side of the rudder. A black witness mark, consistent with the color and texture of a tire, was noted on the separated portion of the right horizontal stabilizer. The airframe and related systems were otherwise unremarkable.

Probable Cause and Findings

Both glider pilots’ inability to see and avoid the other resulting in a mid-air collision.

 

Source: NTSB Aviation Accident Database

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