On March 3, 2002, at 1500 Pacific standard time, an Aeronca C-3, N17438, impacted terrain in a junkyard while in an uncontrolled descent shortly after takeoff from the Sonoma Skypark Airport, Sonoma, California. The airplane was owned and operated by the private pilot under the provisions of 14 CFR Part 91. The airplane sustained substantial damage. The pilot received minor injuries, and a passenger who held a student pilot certificate was seriously injured. Visual meteorological conditions prevailed for the local area flight, and no flight plan had been filed. The pilot informed emergency medical services (EMS) personnel that during the takeoff climb he felt something "snap" on the control stick. The airplane veered sharply to the left. He attempted to correct back to the right, but was unable to do so. The airplane nose dived to the ground with the left wing low. In a written statement to the National Transportation Safety Board, the student pilot indicated that she had been at the airport that morning to do some flying in her airplane. Later in the day she went down to the hangar that housed the accident airplane. The owner and another person were getting the airplane ready to fly. The other person was going to fly it around the area. While the airplane was out flying, the owner asked her if she would "like to solo the C3 next;" she replied with a negative response. The owner asked her a couple of more times if she wanted to fly the airplane. He also told her that it flew just like her own airplane, and she wouldn't have a problem flying it. She stated that she said she would fly it as long as he went up with her first. When the airplane returned, the owner had her get in the airplane and taxi around to get used to the rudder pedals. After she was done taxiing the airplane, she took it over to the fuel pit to refuel it. She then called her dad and asked if she could solo the C-3; she told him that she was going to fly with the owner first. After she fueled the airplane, they got into the airplane and started to taxi to the runway. The student pilot reported that the pilot had her sit in the left seat, the side that had a control stick, rudder pedals, and brakes. The right side, where the owner was seated, had only rudder pedals. She was unsure whether there were brakes on his side. Once on the runway, she advanced the throttle with her right hand and held the control stick with her left hand. She indicated that she didn't know the airplane, so if she had been doing something wrong she figured the owner would have said something. She encountered no difficulties during the takeoff. Once they had climbed over the trees, she stated that the "left wing dropped abruptly." She corrected it "and got the plane back straight [and] level. Or the wings level [at least]." She stated that the owner reached over and grabbed the controls. The student pilot let go of the flight controls, and recalled losing altitude and seeing a house go by. A witness to the accident stated that he saw the airplane veer to the left and then "went right and nose [dived] into the ground." Another witness traveling on Highway 37 reported that the engine was not "sputtering." She was unfamiliar with airplanes, but stated that the engine did not sound like anything was wrong with it. She did note that the airplane was "very low." A Federal Aviation Administration (FAA) inspector examined the airplane. He established flight control continuity, and the control linkages appeared attached and intact. He examined the engine. The spark plugs appeared normal. The inspector manually rotated the propeller; he observed valve train movement, and obtained thumb compression on the two cylinders. The magneto remained attached to the engine and produced spark on one lead. He removed the magneto, manually rotated it, and it produced spark at all of the terminals. He observed no mechanical discrepancies.