On May 5, 2002, about 1000 eastern daylight time, a D'Apuzzo D-260 homebuilt airplane, N112JF, was substantially damaged while landing at Aeroflex-Andover Airport (12N), Andover, New Jersey. The certificated private pilot was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight conducted under 14 CFR Part 91. The pilot stated that about 0930, he departed a private airstrip in Nazareth, Pennsylvania, and flew to 12N. As the airplane touched down on runway 21, the pilot heard a "pop". The left main gear collapsed, and the airplane traveled off the left side of the runway. It came to rest in the grass, and the lower left wing spar sustained damage. The pilot added that he did not land hard. A witness stated that the airplane touched down hard and the landing gear sustained a side load. The witness then heard a "pop," and the airplane veered left. Another witness reported: "...the plane approach at a severe sideway angle. The plane attempted to straighten out but was unable to do so. As the plane touched down it bounced hard." Examination of the left main landing gear by a Federal Aviation Administration inspector revealed that two 5/16-inch bolts secured the spring gear to the airframe. One of the two bolts had sheared, and the other was bent. The sheared bolt was forwarded to the Safety Board's Material Laboratory for further examination. According to a Safety Board Metallurgist, the failure was consistent with a direct shear ductile overstress separation. The reported wind at an airport approximately 10 miles northeast of the accident site, at 0953, was variable at 3 knots.