Aviation Accident Summaries

Aviation Accident Summary DEN08LA127

Midlothian, TX, USA

Aircraft #1

N47JD

Schempp-Hirth Ventus A

Analysis

Witnesses to the accident said the glider appeared to be flying normally when it suddenly pitched up and down, then flew into the ground. This was substantiated by flight data from an onboard recorder. The pilot was fatally injured and portions of the glider's wings and empennage were seperated from the fuselage. The pilot was an 11 time national soaring champion with approximately 50 years experience flying gliders and airplanes. The pilot had very recent symptoms, recent test results, and autopsy findings consistent with serious coronary artery disease. He also had abnormal rhythms on ECG monitoring that would have likely increased his risk of sudden death. The pilot was in the process of scheduling a cardiac catheterization and possible angioplasty. He may have been impaired or incapacitated by pain, an abnormal heart rhythm, or sudden cardiac death. The circumstances of the accident are consistent with an abrupt physical inability to continue controlling the aircraft.

Factual Information

HISTORY OF FLIGHT On July 23, 2008, about 1225 central daylight time (CDT), a Schempp-Hirth Ventus-A glider, N47JD, impacted terrain approximately two miles south of the Texas Soaring Association (TSA) Gliderport (TA11), Midlothian, Texas. The commercial pilot was fatally injured. The glider was destroyed. The personal flight was being conducted under the provisions of Title 14 Code of Federal Regulations Part 91 without a flight plan. Visual meteorological conditions prevailed at the time of the accident. The local flight originated at TA11. The pilot was flying a recreational flight and at the same time providing pre-contest soaring condition reports for a soaring competition at TA11. The pilot was not officially associated with, nor a participant in the competition. Witness reports state the glider appeared to be flying normally when it suddenly climbed abruptly then nosed over into a steep dive and disappeared from view in a forested area. Recovered flight data from an on board recording device substantiated the witness testimony. On scene examination of the glider revealed portions of both wings and the empennage were separated from the fuselage by impact with trees and terrain. PERSONNEL INFORMATION The 85 year old pilot held an Airline Transport Pilot (ATP) certificate with ratings for airplane single-engine land, airplane single engine sea, airplane multi-engine land, airplane multi-engine sea, and a commercial pilot certificate with a glider rating. His last Federal Aviation Administration (FAA) second-class medical was issued on August 30, 1996. The pilot’s log books were not available for examination. The pilot indicated 10,633 total hours on his last application for second-class medical examination on August 30, 1996. The pilot began flying glider aircraft in 1938. He had won eleven National Gliding Championships and been a member of the United States Soaring Team during ten World Soaring Championships. He was the author of approximately 100 Flight Test Evaluation articles for Soaring Magazine. AIRCRAFT INFORMATION The 1981-model Schempp-Hirth Ventus-A, serial number 29, was a mid-wing glider, with a retractable nose landing gear, and was configured for one occupant. The glider was classified as Experimental in Racing and Exhibition categories. According to the airframe logbook, the glider's most recent inspection was completed on April 1, 2008 in accordance with FAR 43, Appendice D (currently Code of Federal Regulations -CFR), with an airframe total time of 5008.8 hours. FLIGHT DATA RECORDER The glider was equipped with a Volkslogger flight data recorder (model/serial number unknown). The device was downloaded at the Texas Soaring Association facilities under the supervision of the FAA. The data included a flight originating at TA11 on July 23, 2008, at 1708:23 UTC (1208:23 CDT) and ending at 1724:59 UTC (1224:59 CDT) for a 16 minute and 36 second duration. During the final two minutes of the flight the data shows the glider making several steep descents and climbs, ending with the loss of approximately 1,700 feet in approximately 20 seconds. METEOROLOGICAL INFORMATION At 1245, the weather observation facility at Midlothian, Texas (KJWY) reported wind from 100 degrees at 8 knots, visibility 10 miles, scattered clouds at 4,000 feet, temperature 90 degrees Fahrenheit, dew point 68 degrees Fahrenheit, and a barometric pressure of 29.99 inches of Mercury. WRECKAGE AND IMPACT INFORMATION The wreckage was located in a wooded area 2.25 miles south of TA11. The debris field encompassed an area approximately 175 feet long and 50 feet wide, on a magnetic heading of 190 degrees. The initial impact point was located approximately 12 feet above the ground in a mesquite tree at the north end of the debris field. The right wing impacted a tree 25 feet south of the initial impact tree eight feet above the ground. The left wing impacted a tree 40 feet south of the initial impact point and four feet above the ground. The right wing was separated from the fuselage near the wing root, with two large sections located near the initial impact point. Approximately one-third of the left wing remained attached to the fuselage. The empennage was separated from the fuselage and lying 76 feet from the initial impact point in the line of travel of the fuselage. Both elevators and ailerons were separated from the empennage and wings, respectfully. The cockpit nose was folded underneath the fuselage and the cockpit sidewalls were each pushed outboard. Schempp-Hirth Ventus-A gliders utilize control rod assemblies for aileron, elevator, and airbrake controls. They use cable assemblies to control the rudder. Examination of the wreckage revealed multiple tie rod ends and linkages for the elevator, left and right aileron and airbrake control systems fractured. All fracture surfaces were examined and displayed 45 degree fracture and shear lip characteristics. When accounting for each separation of the control rods, aileron, airbrake, and elevator controls were continuous from the cockpit controls to each control surface. The rudder control cables were continuous from the rudder pedals to the point the empennage separated from the fuselage just forward of the horizontal stabilizers. The broken control cable ends exhibited broom-straw characteristics. MEDICAL AND PATHOLOGICAL INFORMATION The pilot had seen his cardiologist 6 days before the accident. The pilot reported at that visit he had an episode of dizziness the week prior accompanied by left arm pain. The cardiologist performed a stress echocardiogram on the day of that visit, the report of which noted: "stress induced wall motion abnormalities suggest ischemia." The cardiologist indicated he was "concerned about proximal LAD stenosis" and planned to schedule "left heart catheterization and possibly angioplasty in the next 1 to 2 weeks." Electrocardiographic (ECG) monitoring performed on the day of the cardiologist visit was interpreted as showing "Frequent ventricular premature contractions" and "Occasional supraventricular ectopy, including two atrial runs of non-sustained supraventricular tachycardia." On autopsy, it was noted that the pilot's "coronary arterial system has varying degrees of calcific atherosclerosis; the left anterior descending coronary artery has up to 90% stenosis, the circumflex coronary artery has up to 80% stenosis and the right coronary has up to 80% stenosis." The Office of the Medical Examiner of Dallas County, located in Dallas, Texas, performed an autopsy on the pilot on July 24, 2008. The cause of death was determined to be blunt force injuries. The following medical information is from the medical records maintained on the pilot by the FAA Aerospace Medical Certification Division: 8/30/96 – Electronic record of the pilot’s most recent application for 2nd Class Airman Medical Certificate notes "No" for "Do You Currently Use Any Medication," and "No" for "Heart or vascular trouble." "Total Pilot Time" is noted as 10,633 hours "To Date" and 155 hours in the "Past 6 months." Blood pressure is noted as 106/64. The FAA, Toxicology Accident Research Laboratory, located in Oklahoma City, Oklahoma, conducted toxicological testing on the pilot. Testing for carbon monoxide, cyanide, volatiles and drugs were negative. A prescription medicine bottle bearing the pilot’s name was recovered from the accident scene with the top in place. The prescription was marked "NITROQUICK .4mg."

Probable Cause and Findings

The pilot's inability to maintain aircraft control due to an incapacitating cardiac event. Contributing to the accident was the pilot's poor decision to fly with known serious medical issues.

 

Source: NTSB Aviation Accident Database

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