On May 4, 1997, at 0915 central daylight time, a Lockheed P-38L multiengine airplane, N9005R, registered to Air-Srv., Inc., and operated by Lone Star Flight Museum, collided with a ground operations vehicle while taxiing near Galveston, Texas. The airline transport rated pilot, sole occupant of the airplane, was not injured. A ground operations person was seriously injured, and the airplane sustained minor damage. Visual meteorological conditions prevailed for the proposed Title 14 CFR Part 91 maintenance flight. A flight plan was not filed for the local flight that was originating from Scholes Field Airport at the time of the accident. According to a witness, the P-38L aircraft was being marshaled by ground personnel. The first marshal started moving the aircraft forward and began turning it to the left. The aircraft turned 180 degrees and it appeared to the witness that it was going to be handed off to the second marshal; however, the aircraft continued to turn left striking a yellow cart and the cart's driver with the left propeller. The second marshal reported in a written statement that he was in position at the taxi line to marshal the aircraft. The first marshal started the aircraft moving towards him. The aircraft "pivoted quickly on the left wheel through about 135 degrees and [he] assumed direction of the aircraft." He tried to bring the aircraft forward, but it continued to turn left. He then directed the aircraft to turn right. He heard the left engine increase RPM as if to assist in a right turn, but the aircraft continued turning left. He "directed [the aircraft to] stop, but the aircraft struck the vehicle." The pilot reported to the investigator-in-charge that he was going to test fly the aircraft prior to the air show, and during his "walk around of the aircraft," he did not see the yellow cart. He further reported that the ground operations person put up the aircraft's crew ladder, and proceeded to the rear of the aircraft. He allowed the engines to warm up for approximately 8 to 10 minutes prior to taxiing. The first marshal directed him to move the aircraft from east to west, and he had not quite completed the 180 degree turn when the left propeller struck the yellow cart. The pilot also reported that he saw the yellow cart just as the left propeller hit the cart, and he never saw the second marshal until after the collision. The ground operations person reported to the investigator-in-charge that maintenance was performed on the aircraft the day prior to the accident, and it was to be test flown prior to the air show. The aircraft was towed to the ramp, and he had parked the cart to the left and rear of the left wing tip prior to the pilot arriving. He stood to the left side of the aircraft while the pilot started the engines. He noticed that the crew ladder was not secured, and after gaining the pilot's attention, went to the rear of the aircraft and secured it. He was to follow the aircraft while it taxied, so he went to the yellow cart. He was "getting ready to start it (looking down) when I heard one of the P-38 engines go to power." He looked up, and "all I could see was the left engine cowling almost in my lap as the aircraft completed a quick left turn."