On July 5, 1999, at 1900 central daylight time, a Bellanca BL17-30A airplane, N9520E, was substantially damaged when it collided with terrain while on final approach to the Terry County Airport, near Brownfield, Texas. The non-instrument rated private pilot, sole occupant of the airplane, sustained minor injuries. The airplane was registered to and operated by the pilot. Visual meteorological conditions prevailed for the Title 14 CFR Part 91 personal flight. The 35-nautical mile flight originated from the Lubbock International Airport, near Lubbock, Texas, approximately 1845. The pilot reported to a local law enforcement officer, who responded to the accident site, that the engine lost power on final approach, and "he was not quick enough to switch the fuel selector to the other tank." The officer reported that the wing tanks were compromised during impact with the ground, and he found evidence that some fuel spilled on the ground. A pilot, who witnessed the accident at the Terry County Airport, stated that he observed the airplane stall as it cleared the powerlines at the approach end of runway 20. The witness reported that "the left wing of the airplane dropped abruptly and the airplane nosed down impacting the ground in a left wing low attitude, approximately 100 yards short of the landing threshold." Examination of the airplane by the airport manager revealed that both wings were "destroyed by the impact with the ground." Additionally, the 3-bladed propeller separated from the engine. There was no fire. Examination of the fuel system by an FAA inspector revealed that the airplane was equipped with an extended range fuel system which encompassed a total of 7 fuel cells. There were 3 cells in each wing and a fuselage tank aft of the baggage compartment. In the recommendation block of the enclosed NTSB Form 6120.1/2, the pilot stated that the accident could have been prevented by "better fuel management" and "better attention to all gauges (fuel pressure, manifold pressure) to possibly be aware sooner of a possible problem." The pilot further stated that he estimated that he had approximately 40 gallons of fuel aboard the airplane prior to his departure from Lubbock.