On August 22, 2004, at 1350 eastern daylight time, an amateur built S-51D, N151BW, was substantially damaged during landing at the Bowman Field Airport (LOU), Louisville, Kentucky. The certificated airline transport pilot was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the flight which originated at the Clark County Airport (JVY), Jeffersonville, Indiana. The personal flight was conducted under 14 CFR Part 91. According to the pilot, shortly after touchdown on runway 24, he placed the propeller into the Beta range and the airplane began to veer to the right. He then applied left rudder to compensate, and as the airplane began to move, the right wingtip scraped the runway. After realigning the airplane on the centerline of the runway, the pilot released left rudder input and the left main landing gear collapsed. As the airplane veered to the left, the pilot applied right rudder, and the right main landing gear collapsed. The airplane then slid to a stop on the remaining runway. Examination of the airplane by a Federal Aviation Administration (FAA) inspector after the accident revealed that the left wing spar was buckled. No pre-impact mechanical deficiencies were noted with the airplane. Additionally, according to the FAA inspector, the pilot had recently purchased the airplane, and the accident occurred during his first hour, and fifth landing in it. The winds reported at LOU, at 1353, were from 110 at 7 knots.