On August 18, 1996, at 1600 central daylight time, a Taylorcraft 19, N6630N, sustained substantial damage on landing on runway 9 (2,640' x 100' dry/turf), near Shakopee, Minnesota. The pilot reported that the right main landing gear dug into the terrain and the airplane nosed over. The pilot and two passengers reported no injuries. The personal 14 CFR Part 91 flight was operating in visual meteorological conditions. No flight plan was on file. The airplane departed the same airport on a local flight about 1500 for a local flight. The pilot stated that during rollout at approximately 30 MPH the right main landing gear collapsed and the airplane nosed over. A subsequent examination found that the bungee cord attach tubing to the right main landing gear had failed from internal corrosion. This tube is not visible during normal pre-flight nor is it easily examined during an annual inspection because it is covered by the bungee cord which is only removed for replacement. The time in service for the airplane was 2,212 hours. It had been 37 hours since the last annual on August 2, 1995. Total time on the bungee cords was not determined.