On March 27, 2000, about 1400 Eastern Standard Time, a Robinson R-22B, a helicopter, N2260W, was substantially damaged while landing at the Dillant-Hopkins Airport, Keene, New Hampshire. The certificated flight instructor (CFI) and commercial pilot were not injured. Visual meteorological conditions prevailed and no flight plan had been filed for the local instructional flight conducted under 14 CFR Part 91. The CFI stated he was providing flight instruction to the commercial pilot, who was training for a CFI rating. According to the CFI, the commercial pilot was practicing an autorotation to Runway 20. The CFI further stated: "As [the helicopter] approached approximately 50 feet above the runway, [the commercial pilot] started the cyclic flare, the helicopter nose pitched up and all seemed quite normal. As the flare was held, it appeared that we were starting to fall through the bottom. I failed to react soon enough to this situation and the helicopter contacted the ground landing on the aft portion of the skids...." The helicopter's main rotor severed the tail boom, and the helicopter rolled onto its left side. The pilots did not report any mechanical problems with the helicopter. The CFI reported 1,180 hours of total flight experience, of which 497 hours were in rotorcraft, with 279 hours in the make and model of the accident helicopter. Additionally, the CFI reported 40 hours of flight time as a flight instructor.