On July 22, 2010 about 1145 central daylight time, an Aero Commander S2R, N51AR, was taxiing for take-off when it collided with a parked and unoccupied airplane, Piper PA-18A 150, N2287W, at McCook Ben Nelson Regional Airport (MCK) McCook, Nebraska. The fuselage, empennage, and both wings of N2287W were substantially damaged from impact with N51AR. Both airplanes were substantially damaged by the postimpact fire. The pilot of N51AR sustained serious injuries and no other persons were injured. N51AR was owned by Griff H Mallek DBA and was operated by Red Willow Aviation Spraying, Inc. under the provisions of 14 Code of Federal Regulations Part 137 as an aerial application flight. Visual meteorological conditions prevailed at the time of the accident and a flight plan had not been filed for the local flight. N51AR was refueling and reloading while parked on the ramp with the propeller operating. During that time N2287W arrived and parked on the airport ramp directly in front of N51AR. The occupants of N2287W exited the airplane and left the area. The pilot of the tailwheel equipped N51AR completed refueling and reloading and then began to taxi for take-off. He made no turns and taxied straight ahead. N51AR taxied directly into the parked and unoccupied airplane and the operating propeller impacted the second airplane. Witnesses reported that both airplanes were immediately engulfed in fire. The pilot of N51AR evacuated the airplane unassisted and the fire was extinguished by firefighters.