NTSB Factual Report

HISTORY OF THE FLIGHT

On July 14, 2007, at 1745 eastern daylight time, a Burkhart Grob Flugzeugbau G102 ASTIR CS, N775SS, registered to Knauff & Grove Inc. and operated by a private individual, as a 14 Code of Federal Regulations Part 91, personal flight, collided with trees during approach to the Ridge Soaring Gliderport (79N), Unionville, Pennsylvania. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local flight. The pilot, the sole occupant, was killed and the glider incurred substantial damage. The flight originated earlier that day, about 1640, from the same gliderport.

Witnesses stated that they observed the glider flying on the downwind leg after hearing the pilot's radio call that he was entering the landing pattern. The downwind leg and the turn onto base leg were performed at a steady airspeed and an appropriate, nose-below-the-horizon, attitude at perhaps 200 feet above the trees along the ridge-line. As the glider finished the base leg turn, the nose of the glider pitched suddenly and rapidly down so the glider was in a vertical attitude, which it held for some three seconds, as it disappeared into the forest. There was no attempt to raise the nose before the glider entered the trees. The witness went to the aid of the pilot. The pilot remained in the wreckage suspended in the trees. The pilot complained about having trouble breathing and apologized for damaging the glider. The witness stated the pilot said "I don't know why I did that."

AIRCRAFT INFORMATION

The glider, a Burkhart Grob Flugzeugbau G102 ASTIR CS, a single-seater glider, was manufacture in 1976. The last inspection to the glider, an annual, was conducted in July 2007, at a total time of 963 hours in service. The glider had cumulated a total of five flight hours since the inspection at the time of the accident. The glider's maintenance logbook records were examined by a Federal Aviation Administrator (FAA) inspector; no discrepancies were noted.

PERSONNEL INFORMATION

The pilot, age 65, held a private pilot certificate with airplane single engine land, instrument airplane, and glider ratings. He was last issued a third-class medical certificate on June 27, 2002, with limitations; must wear corrective lenses. The pilot reported a mental disorder and a prior surgery, and documented, at the time of the medical, a total of 1,700 flight hours in all aircraft. The pilot's glider logbook, dating from May 19, 1999, to July 28, 2007, was reviewed; a total of 114 hours glider time was documented with proper endorsements being noted.

METEOROLOGICAL INFORMATION

The UNV automatic surface weather observation site is located 4 miles southeast of the accident site. At 1740 the automatic surface weather observation was winds 220 degrees, gusting 10 to 16 knots, visibility 10 statue miles, clear, temperature 84 degrees Fahrenheit (F), dew point 8 degrees F; altimeter 30.05 inch of mercury.

WRECKAGE AND IMPACT INFORMATION

The glider came to rest suspended in the air among the trees in a right wing low attitude with the right wing tip contacting the ground. The left wing leading edge made contact with several tree branches, which the glider got lodge to and remained in an unstable condition. The fuselage from aft of the cockpit to the empennage stayed intact, both wings remained attached to the fuselage. The bottom of the forward fuselage, cockpit section, broke and remained attached by flight control cables suspended in the air. The canopy was missing and the cockpit section was ripped open. A wreckage examination by the responding FAA inspector established flight control continuity and no discrepancies were noted.

MEDICAL AND PATHOLOGICAL INFORMATION

A postmortem examination of the pilot was conducted under the authority of the Coroner of Centre County, Bellefonte, Pennsylvania, on July 15, 2007. The cause of death for the pilot was attributed to multiple traumatic injuries. The autopsy report noted the presence of small tumors in one adrenal gland (pheochromocytoma) and one parathyroid gland (parathyroid adenoma). The autopsy report also noted the presence of severe heart disease, with 90% occlusion of a coronary artery and the "suggestion of a tiny amount of acute thrombus" in one section of that coronary artery.

The FAA's Civil Aeromedical Institute (CAMI) conducted a toxicological examination on June 13, 2007. Levels of Mirtazapine were present in the blood and urine. Levels of Dihydrocodeine, Hydrocodone, Hydromorphone, Oxazepam, Temazepam, Nordiazepam, Ibuprofen, and Acetaminophen were present in the urine. No alcohol was detected.

The pilot's most recent application for medical certificate in 2002 indicated a history of back surgery in 1982 and of previous treatment with antidepressants, though no detail was provided regarding those treatments.

NTSB Probable Cause

The pilot's failure to maintain control of the glider for undetermined reasons.