San Andreas, CA, USA
N50912
Aeronca O-58B
A witness observed the aircraft descend in controlled, gliding flight and "pancake" onto a rock outcropping. He didn't think the crash site was where a pilot would intentionally land. There were more suitable areas in the nearby vicinity. Earlier in the day the airplane was fueled to capacity (2.5-hours endurance). The pilot had flown to an airport about 50 minutes distant and was returning at the time of the accident. The accident site is about 5 miles from the origin airport. Inspection of the aircraft failed to reveal any mechanical anomaly. An autopsy of the pilot revealed, among the findings: 1) Acute thrombus, diagonal branch of left anterior descending coronary artery; 2) Severe coronary artery atherosclerosis; and 3) Cardiomegaly with left ventricular hypertrophy.
On July 6, 2001, at 1125 hours Pacific daylight time, an Aeronca O-58B, N50912, impacted hilly terrain about 5 miles north of the Calaveras County Airport, San Andreas, California. The commercial certificated pilot sustained fatal injuries, and the airplane was substantially damaged. The owner/pilot was operating the airplane under the provisions of 14 CFR Part 91. The personal cross-country flight departed Auburn, California, at an unknown time, and was destined for the Calaveras County Airport. Visual meteorological conditions prevailed and no flight plan was filed. An electrical contractor was driving north on Gold Strike Road, which passes about 100 yards from the accident site, and witnessed the crash occur. He was traveling 40 - 45 miles per hour and said the airplane was in front of him over Gold Strike Road and traveling a little faster than he was. The airplane was about 20 feet above the road when it came to a curve in the road. When he rounded the curve and next saw the plane, it had deviated away from the road and continued ahead in a controlled manner until it impacted on a rock outcropping. He got to the airplane within 30 - 45 seconds and called to the pilot but the pilot showed no sign of life. He didn't think the crash site was where a pilot would intentionally land. There were more suitable areas to the right nearer the road. An area resident who lives about 1.5 miles north of the accident site observed an airplane fly over his home from north to south about 1100 on the day of the accident. After looking up at the plane, he turned his attention away but heard an unusually loud "pop" sound after which the engine sound ceased. His view of the plane was then blocked by a hill to the south of his location. He said the surface winds at his location were gusting out of the south about 30 knots. An inspector from the Federal Aviation Administration (FAA) Flight Standards District Office in Sacramento, California, responded to the site, which was in a ravine about 5 miles north of the Calaveras County Airport. All of the aircraft was present at the site and there was no fire. According to the inspector, the ravine was oriented northwest-southeast. A county road (Gold Strike Road) paralleled the ravine on the northeast side, passing about 100 yards from the accident site, and the ravine slopped upward about 35 degrees on each side. The aircraft was located on the southwest face of the ravine and was headed parallel to it (315 degrees magnetic). To the southeast the slopes of the ravine were grass covered and opened into a more-or-less open field; however, the airplane came to rest in a small rock outcropping. In front of the aircraft was an area of scrub oak trees. There were no ground scars outside the immediate area of the wreckage and the inspector said it appeared the airplane "pancaked" onto the rocks with low forward airspeed and stopped almost instantaneously. The inspector said that, had the aircraft landed about 500 feet sooner (to the southeast), it would have been in an open, grassy field. There was damage to the aircraft's engine and engine mount, the firewall and lower fuselage, and the main landing gear. The engine was visibly intact and there was no visible oil externally on the engine. The remainder of the aircraft was intact. Although the airplane was resting in a tail-low attitude, there was no fuel in the (overhead) fuel tank and no fuel smell at the site. The airplane carries a portion of its fuel in a header tank forward of the instrument panel. The fuel sump bowl, below the header tank, was broken by impact. The emergency locator transmitter beacon activated and was turned off by the inspector. The aircraft was equipped with lap-type occupant restraint belts but no shoulder belt restraints. One blade of the wooden propeller was shattered and the other was undamaged. Early responders reported turning off the fuel valve and moving the magneto switch from "both" to "off." The carburetor heat was "off." The aircraft was further examined by a Safety Board investigator at the facilities of Plain Parts, Pleasant Grove, California on July 26, 2001. The engine was mechanically intact and there was compression and valve action at all 4 cylinders when the propeller was rotated. The spark plug electrodes were light gray in color and free of deposits. The spark plugs sparked across the electrodes when the magnetos were rotated by hand. The carburetor was broken from the engine and the carburetor heat box was crushed. The carburetor inlet screen was clear and the firewall fuel sump was broken. The manager of the Calaveras County Airport told the FAA inspector that the pilot fueled the airplane earlier in the morning (added 11 gallons fuel), and told her he was flying to Auburn for breakfast. The direct line distance from Calaveras County airport to the Auburn airport is 53 nautical miles. The total fuel capacity of the airplane is 12 gallons. According to the Teledyne Continental party representative, 12 gallons fuel equates to about 2.5 hours endurance and the airplane cruises about 70 knots. Another pilot, who had breakfast with him at Auburn, reported the pilot was alert, jovial, and, to him, entirely (physically) normal. An autopsy of the pilot was performed by the Calaveras County Office of the Coroner. Among the Final Anatomic Findings were: 1) Acute thrombus, diagonal branch of left anterior descending coronary artery; 2) Severe coronary artery atherosclerosis; and 3) Cardiomegaly with left ventricular hypertrophy.
An in-flight collision with terrain for undetermined reasons.
Source: NTSB Aviation Accident Database
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