On October 18, 1997, at 0915 mountain daylight time (mdt), a Bellanca 7GCBC, N88119, operated by an airline transport pilot, sustained substantial damage when on approach, the airplane departed controlled flight and impacted into a field 100 yards from the approach end of a private airstrip. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under 14 CFR Part 91. There was no flight plan on file. The pilot and the passenger on board received minor injuries. The local flight originated at a private airstrip one mile north of Rapid City, South Dakota. In his written statement, the pilot said that the winds at the destination airstrip "appeared to be light on the ground and out of the north-northwest, judging by the windsock. I entered a normal traffic pattern, rolled out on final and flew final at my normal approach speed with full flaps. At approximately 100-120 feet, I hit a windshear. The wind either stopped or abruptly became a tailwind. The aircraft quickly settled." The pilot said that he rapidly applied power, but hit the ground before it could take effect. A witness on the ground, near the location of the accident, noticed that the wind was changing directions, "sometimes from the northwest, west, and east." The witness watched the airplane approach and fly over his location. The witness said that about 100 feet above the ground, "the airplane appeared to almost stop, then drop nearly vertical." The witness said that he heard the power being added before the airplane struck the ground. The Federal Aviation Administration (FAA) inspector who examined the airplane at the accident site found the airplane resting upright in a field. The left wing and internal structure [spars] were bent upward. The airplane's empennage was twisted right. The main landing gear were bent upward and broken off. The propeller showed torsional bending and chordwise scratches. Flight control continuity was confirmed. Examination of the engine, engine controls and other airplane systems revealed no anomalies.