On August 18, 2010, at 0931 central daylight time, a Piper Aerostar 601P, N601PP, received substantial damage on impact with terrain near Baraboo, Wisconsin. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The airline transport pilot sustained serious injuries. The flight originated from Reedsburg Municipal Airport (C35), Reedsburg, Wisconsin, about 0926 and was en route to Baraboo Wisconsin Dells Airport (DLL), Baraboo, Wisconsin. According to the Federal Aviation Administration, the airplane had the left cylinder temperature probes replaced at C35. The pilot was repositioning the airplane to DLL. While approaching DLL, the pilot noticed a differential reading between the left and right engine cylinder/exhaust temperatures. While preparing to land, the pilot moved his seat back so as to get a better view of the engine temperature gauges located on the right side of the panel. While he was recording the gauge indications on paper, the airspeed decreased, the sink rate increased, and the airplane impacted trees and a corn field about 1/2 mile north of the approach end of runway 19.