On December 21, 2018, about 1145 central standard time, a Cessna 172M, N254RA, registered and operated by Reynolds Aviation, Beach City, Texas, sustained substantial damage when it collided with a tower wire about 10 miles south of the Abilene Regional Airport (AB), Abilene, Texas. The commercial pilot, who was the sole occupant, was not injured. Visual meteorological conditions prevailed and a flight plan was not filed. The pipeline aerial observation flight was being conducted under the provisions of Code of Federal Regulations Part 91. The flight originated about 1000 from the Draughon-Miller Central Texas Regional Airport (TPL), Temple, Texas, and was enroute to the Winston Field Airport (SNK), Snyder, Texas. The pilot stated that he was conducting an aerial pipeline inspection. He stated that he was looking down in the cockpit, writing down pipeline observation information. At the same time, he felt a pull to the left. The airplane struck a tower wire. The pilot stated that he did not see the tower wires. The pilot was able to control the airplane, immediately declared an emergency, and landed the airplane at ABI, which was about 10 miles north of the wire strike. Inspection of the airplane revealed a 4-foot section of the left wing was torn off the airplane, just outboard of the left aileron. Figure 1. Overhead Image of Pipeline Route and Tower/Wire LocationsThe pilot stated in NTSB Form 6120, that many pipeline patrol operations have an observer on board in addition to the pilot, one writing down information, and one looking outside the airplane. He also stated that he could have waited to write down information after passing the tower area.