Motorized Glider N807B Experienced An In Flight Breakup While Maneuvering Near Minden Nevada

A Schempp-Hirth Nimbus-4DM motorized glider, N807BB, experienced an in-flight breakup while maneuvering near Minden, Nevada. The commercial glider pilot and a passenger were fatally injured, and the glider was destroyed. The glider had departed from Minden-Tahoe airport at 1240 and was operated by the owner/pilot under the provisions of 14 Code of Federal Regulations (CFR) Part 91. No flight plan was filed for the local area soaring flight. The glider was certificated in the United States in the experimental category for exhibition and racing, and it was also certificated in Germany in the standard class, utility category.

A glider pilot who witnessed the in-flight breakup stated that his glider was soaring about 1,000 feet below the accident glider when he observed the accident glider in a high-speed spiral with a 45-degree nose-down attitude. After two full rotations, the rotation stopped, the flight stabilized on a northeasterly heading, and the nose pitched further down to a near-vertical attitude. The accident glider was observed to level its attitude, with the wings bending upward and the wing tips coning higher. The outboard wing tip panels departed from the glider, the wings disintegrated, and the fuselage dove into the ground.

Other witnesses who were flying gliders in the area stated that the accident glider was in a tight turn, as if climbing in a thermal, when it entered the spiral. In the later portion of the sequence observed by these witnesses, the glider appeared to be recovering from a spin.

The accident glider was climbing in a thermal when one witness saw it at 9,000 feet msl. The glider then departed the thermal on an easterly heading for another thermal. When the witness saw the glider again, he stated that it was coming directly towards him at a 45-degree nose-down angle with the wings bowed. The witness was 180 degrees into a 360-degree turn and heard a Mayday call (later determined to have come from another glider pilot who saw the accident sequence). He did not see the accident occur, but did see fiberglass particles scattering down.

Another witness saw the accident glider climb from 9,000 feet to 11,000 feet msl. He also saw the glider in a spiraling 45-degree nose-down angle. He stated that the nose-down attitude increased to 80 degrees after completing one to two 360-degree turns. The witness reported that the glider became stabilized on a westerly heading with the wings bowed up 45 degrees. He then observed the wings collapse.

Another witness caught something out of the corner of his eye moving at a very high rate of speed. He reported that the accident glider spiraled down and completed one 360-degree turn. He stated that he could not tell if the glider was in level flight when the wings failed.

One ground witness reported that the accident glider had a 45-degree nose-down attitude and was in a "hard over left hand turn."