On September 27, 2000, at 1450 mountain daylight time, a Piper PA-31-350, N114SA, landed with the landing gear retracted at Cal Black Memorial Airport, Blanding, Utah, Near Halls Crossing, Utah. The airline transport certificated pilot and his four passengers were not injured and the aircraft sustained substantial damage. The flight was operating as an "on demand" air taxi flight under Title 14 CFR Part 135 and no flight plan was filed. The flight departed Bullfrog Basin Airport, Glen Canyon National Recreation Area, Utah, at 1447. According to the pilot, he had picked up some passengers at the Bull Frog Basin Airport, 9 miles northwest of Cal Black Airport, and was picking up more passengers at Cal Black. He made a straight in approach to landing at Cal Black and during the approach was discussing the shortened runway, which was undergoing repairs, with the UNICOM operator. He said that he made his approach to runway 19 at Cal Black and lowered landing flaps, but due to the distraction of his UNICOM conversation, he forgot to lower the landing gear. According to his statement, he heard the landing gear warning horn when he reduced power for landing, but it was then too late to initiate a go-around. He said the aircraft slid to a stop following landing and he assisted his passengers from the aircraft, which had suffered damage to the belly, propellers and flaps.