N2198Z

On June 3, 1995, at 1100 hours Pacific daylight time, a Cessna 180F, N2198Z, collided with a tree after a low pass at Templeton Meadows Airstrip, 10.5 statute miles west of Cartago, California. The aircraft was owned and operated by the pilot and was on a personal flight. The aircraft was substantially damaged. The certificated airline transport pilot and his passenger were seriously injured. The flight originated at Saline Valley Hot Springs private airstrip, 21.5 statute miles northeast of Lone Pine, California, at 1000 hours for a destination of Hanford Municipal Airport, Hanford, California. Visual meteorological conditions prevailed.

The aircraft was examined by the Forest Service area division chief. He reported the elevation of Templeton Meadows Airstrip is about 8,500 feet msl. The aircraft's right wing collided with a tree branch at a height of about 30 feet agl. The propeller broke off at engine crankshaft flange and was observed to have symmetrical damage. The throttle and propeller control were full forward. The mixture control was 1 inch out. The flaps were set at 40 degrees and the trim pitch was 1 inch nose up. The division chief stated his opinion that the aircraft collided with a tree while executing a low pass over a high-altitude remote dirt strip in mountainous terrain.

The pilot was interviewed by telephone on June 8. He reported that they passed over the Strawberry Meadows area of the Sierra Nevada Mountains and noted that the snow had melted around the Templeton Airstrip. The pilot and his passenger intended to return to the area in the next several weeks and the pilot decided to make a low pass over the airstrip to check for general condition of the runway. While performing the low pass at an altitude he said was 500 feet agl, he "encountered a downdraft or thermal which was greater than the ability of the aircraft to climb at that density altitude." The aircraft could not outclimb the rising terrain and the right wing collided with a tree. The pilot reported that the winds were generally calm and the temperature was warm. The pilot stated that there were no mechanical malfunctions or failures of the engine.

On June 21, 1995, the engine was examined at a storage facility in Santa Paula, California, with the assistance of a technical representative of Teledyne Continental Motors. A portion of the number 5 cylinder head was broken off by impact forces in the area of the intake port and the associated rocker cover was broken open. The crankshaft was rotated by hand and mechanical continuity was established throughout the engine. Cylinders number 1 through 4 and 6 produced compression when the crankshaft was rotated. The engine manufacturer's technical representative stated that cylinder number 5 did not produce compression because of the previously described impact damage. Both magnetos produced spark in proper sequence when the crankshaft was rotated. Fuel was present, and its appearance and odor was consistent with 80/87 Avgas. No evidence of any preimpact malfunction was noted.