On May 9, 2003, approximately 1415 Pacific daylight time, an experimental Allen Starduster Too SA-300, N147DA, registered to Hawkeye Aviation Inc., operated by the pilot as a 14 CFR Part 91 instructional flight, collapsed the landing gear during the landing roll at Yakima Air Terminal, Yakima, Washington. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local flight. The private pilot and flight instructor were not injured. The aircraft was substantially damaged. During a telephone interview, the private pilot reported that the purpose of the flight was to fulfill an insurance requirement for him to accomplish 15 hours of dual instruction in the aircraft. The pilot reported that he had accomplished about six landings without incident prior to the final landing. The pilot stated that during the landing roll on runway 27, when the tailwheel contacted the surface, a severe vibration was felt. The aircraft immediately weathervaned to the right into the wind. Left rudder control and braking action were not effective and the aircraft subsequently ground looped. The left main landing gear collapsed and the left side lower wing contacted the surface. Post-accident inspection of the aircraft by a Federal Aviation Administration Inspector from the Spokane, Washington, Flight Standards District Office, reported that the rear spar on the lower left side wing was cracked. The inspector also reported that there was a loss of friction to the tailwheel anti-shimmy clutch. Both steering springs were also disconnected. At 1356 the airport was reporting the winds from 40 degrees at 7 knots.