On August 8, 2002, at 1600 central daylight time, a Piper PA-28-151 single-engine airplane, N43473, was substantially damaged during a forced landing following a loss of engine power near Masterson, Texas. The non-instrument rated commercial pilot, sole occupant of the airplane, was not injured. The airplane was owned and operated by a private individual under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the personal flight, and a flight plan was not filed. The local flight originated from the Perry Lefors Field Airport (PPA), near Pampa, Texas, approximately 1500. The FAA inspector, who traveled to the accident site, reported that the 1,000-hour pilot experienced a loss of engine power and landed in a rocky pasture east of Masterson, Texas. The right wing spar, main landing gear attachment fittings, and the engine firewall were structurally damaged. A detailed inspection of the Lycoming O-320-E3D engine revealed that an aluminum sliver, consistent with a piece of thread which was found missing on the carburetor housing boss, was found between the needle valve and carburetor housing seat, preventing unrestricted operation of the needle valve, which resulted in the fuel starvation of the engine. Despite several attempts by the Investigator-In-Charge to obtain a completed Pilot/Operator Aircraft Accident Report (NTSB Form 6120.5) from the pilot, one was not obtained.