On February 18, 2002, at 1330 central standard time, a Cessna 177 airplane, N3402T, was substantially damaged when it impacted terrain near Pond Creek, Oklahoma. The airplane was registered to and operated by Eagle Sky Patrol, of Lead, South Dakota. The commercial pilot, who was the sole occupant of the airplane, sustained serious injuries. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 pipeline patrol flight. The flight originated from the Pratt Industrial Airport, Pratt, Kansas, at 1155, and its destination was the Captain Jack Thomas/El Dorado Airport, El Dorado, Kansas. On the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), and in a telephone interview with the NTSB investigator-in-charge, the pilot reported that he was checking exposed pipe and damaged markers at 300 feet agl. Before "dozing off," he stated that "everything was quiet and nothing to report," and that he remembered seeing Pond Creek Airport and passing markers 97 and 98. The next thing he remembered was the airplane hitting the ground, sliding approximately 240 feet, and coming to rest upright in a wheat field. The pilot secured the airplane, called for assistance, and exited the airplane. A 72-hour sleep log provided by the pilot indicated that on February 15, he slept 7 hours 5 minutes; on February 16, he slept 7 hours 25 minutes; and on February 17, he slept 7 hours 15 minutes. An examination of the airplane by an FAA inspector revealed the nose landing gear had been sheared off, the firewall was buckled, and both propeller blades were bent aft. The left main landing gear had separated and impacted the left horizontal stabilizer. The left wing root area was buckled.