On August 20, 1997, approximately 0745 mountain daylight time, a Piper PA-31-350, N35164, operated by Flight Line, Inc., d/b/a American Check Transport, was substantially damaged when it collided with a truck while taxiing for takeoff at Hayden, Colorado. The commercial pilot-in-command, commercial pilot-rated passenger, and the truck driver were not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the nonscheduled domestic cargo flight being operated under Title 14 CFR Part 135. The flight was originating when the accident occurred. According to the company's director of operations, the pilot-rated passenger was aboard the airplane for familiarization purposes. Although he was an employee of the company, he did not have any flight crew duties. In the accident report, the director of operations said that after the cargo had been unloaded and loaded between the airplane and a UPS (United Parcel Service) truck, the pilot prepared for the next trip leg. He thought the truck had moved out of the way. As he began to taxi, the airplane's horizontal stabilizer struck the corner of the truck.