On July 26, 1998, approximately 2200 mountain daylight time, a Cessna 172M, N5147N, collided with terrain while in cruise flight near Franktown, Colorado. The private pilot, the sole occupant onboard, was not injured. The aircraft was being operated as a personal flight under Title 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan had been filed. The flight originated at Front Range Airport, Watkins, Colorado, at 2045. According to the pilot's accident report, he had flown to Centennial Airport to practice touch and go landings. He said he departed the airport traffic pattern on an easterly heading, tuned the no. 1 navigation receiver to the Falcon Vortac, and rotated the OBS (Omni Bearing Selector) to 350 degrees. It was his intention to cross the 360 degree radial (sic, 180 degree radial), and then fly direct to the Falcon Vortac and direct to Front Range Airport. By flying this route, he would avoid the Buckley ANG and Denver International Airport airspace. After he flew what he thought was an easterly heading (the evidence indicates it was most probably a south-southeasterly heading) for 8 to 10 minutes and noting the CDI (Course Deviation Indicator) needle had failed to center, he made a shallow 360 degree turn and looked for recognizable landmarks. He then rotated the OBS to go direct to the Falcon Vortac and "reset the directional gyro to the magnetic compass, making a significant correction." (In a telephone interview with the pilot, he said he then descended to 6,500 feet msl). After flying this heading for a minute, the airplane collided with terrain. The accident location was near Franktown, Colorado, about 11 miles south-southeast of Centennial Airport (see the attached Denver TCA chart). Weather conditions at Centennial Airport (the point of departure) consisted of clear skies and greater than 10 miles visibility. The pilot said it was a dark night. Airplane damage consisted of a bent propeller, nose landing gear bent aft, broken windshield, crumbled engine cowling, and a broken left wing tip.