On October 3, 1998, at 1210 mountain daylight time, a Piper PA-28-180 airplane, N8194W, owned and operated by the pilot, was substantially damaged during a forced landing following a loss of engine power near Horizon City, Texas. The airline transport rated pilot was seriously injured, one passenger sustained minor injures and two additional passengers were not injured. Visual meteorological conditions prevailed for the Title 14 CFR Part 91 personal flight, that was en route to El Paso, Texas. The flight originated from the San Antonio International Airport, San Antonio, Texas, at 0830 and no flight plan was filed. The pilot reported in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) that during the preflight inspection, he checked the airplane's fuel tanks and noted that each wing fuel tank was filled to within "1 inch" of the top. He added that no water was found when fuel was drained from each of the airplane's three fuel sumps. The pilot who had accumulated a total of 5,700 flight hours, calculated a flight time of 3 hours and 30 minutes for the flight from San Antonio to El Paso, where he planned to refuel the airplane. The pilot stated that once airborne, the airplane encountered unforecasted headwinds and he recalculated the time en route to be a total of four hours. During the flight the pilot observed that the fuel gauges were reading lower than he expected, but he thought the airplane had enough fuel to reach the West Texas Airport, El Paso, Texas. Subsequently, the right tank ran out of fuel. Fifteen minutes later, after flying for a total of 3 hours and 50 minutes, the left tank ran out of fuel and the engine lost power. A forced landing was executed to rough and uneven terrain, 7 miles southeast of the West Texas Airport. An FAA inspector examined the airplane at the accident site and reported that ground scars indicated that the airplane initially impacted a sandy, brush covered "hillock", approximately 10 feet in diameter. The airplane came to rest upright on a second hillock, 35 feet from the initial impact point. The left fuel drain was opened and no fuel came out. The right fuel drain was not accessible. No fuel was found on the ground in the vicinity of the airplane. A stick was inserted into each fuel tank to determine the level of fuel in each tank. The left tank was empty and the right tank contained 1/4 inches of fuel. The FAA inspector added that the lower section of the engine firewall was damaged. The right wheel was found separated from the airplane and the right landing gear strut assembly was bent rearward, toward the trailing edge of the flap.