On April 2, 1995, at 0330 central daylight time, a Beech G18S, N512E, was substantially damaged during landing roll at Springdale, Arkansas. The airline transport rated pilot was not injured. Visual meteorological conditions prevailed for the Springdale Air Service Title 14 CFR Part 135 on-demand cargo flight from Little Rock, Arkansas to Springdale. The operator reported the following information. During the landing rollout, the pilot observed flames coming from the right engine nacelle. He stopped the airplane on the runway, exited, and attempted, without success, to extinguish the fire with a hand held fire extinguisher. The fire continued to burn until put out by the local fire department. Fire consumed the right engine nacelle, inboard right wing, and a portion of the right side of the fuselage. Due to the extent of the fire damage to the right engine nacelle, the source of the fire could not be determined.