On October 6, 1996, at 1123 hours Pacific daylight time, a Piper PA-28-180, N6614J, operated by the pilot, collided with terrain about 2 miles south of the Ely Airport, Ely, Nevada. Visual meteorological conditions prevailed, and a visual flight rules flight plan was filed. The airplane was destroyed by impact forces and a postimpact ground fire. The private pilot and three passengers were seriously injured. The flight was originating at the time of the accident. Witnesses reported that the airplane took off using runway 18, which is 5,998 feet long. The airport's elevation is 6,255 feet mean sea level. The National Transportation Safety Board calculated that the approximate density altitude was 8,000 feet. The pilot reported that the pretaxi, taxi, and engine run-up procedures were accomplished without any complications. He leaned the mixture for takeoff, extended the wing flaps one notch, and took off. The airplane initially climbed at a 400- to 500-foot-per-minute rate, but then the engine started to "cough/sputter every five seconds or so . . ." The pilot further reported that he reset the mixture control to the full rich position and verified that the carburetor heat was off; however, the engine continued to sputter. Unable to maintain altitude, the pilot turned left toward an emergency landing area. The airplane crashed into an open field while in a left wing low attitude. Several witnesses observed the crash. One of the witnesses reported that seconds before the impact, the airplane was "swaying back and forth." Another witness reported seeing the airplane's nose pitch up and down several times. Thereafter, the airplane entered a steep left bank and descended until impacting the ground. The left, rear seated passenger reported that nothing unusual occurred during the engine run-up or takeoff roll. He then described the accident flight as follows: "Climb out was normal for approximately 30 seconds, reaching an estimated altitude of 100 to 200 feet. At this time the engine began to run rough. The best description of how the engine was running is to compare it to a four cylinder engine running on three cylinders. The pilot tried several things to improve engine performance. I vaguely remember the pilot switching fuel tanks and I think he adjusted the carburetor heat . . . None off his attempts corrected the problem and the engine continued to run rough, not getting worse or better. Our angle of attack was getting rather steep and the pilot commented that he would adjust the flaps . . ." The airplane turned left, and seconds later it crashed. During an October 11, 1996, telephone interview, the passenger reported that when the engine started sputtering, it sputtered consistently throughout the remainder of the flight. The airplane seemed to stall as it descended into the terrain. The fire damaged airframe and engine were recovered from the accident site and examined by representatives from the Federal Aviation Administration, The New Piper Aircraft Company, and Textron Lycoming Engines. In summary, the parties reported finding no evidence of any preimpact malfunctions with the airframe or catastrophic failures within the engine. However, due to the extent of the fire, various engine components and accessories could not be completely examined. These components included the magnetos, the carburetor, the engine driven fuel pump, and various portions of the induction system.