On July 8, 1999, about 1545 Eastern Daylight Time, a Cessna 172, N7164Q, was substantially damaged while landing at Mattituck Airport (21N), Mattituck, New York. The student pilot was not injured. Visual meteorological conditions prevailed for the local flight. No flight plan was filed for the instructional solo flight conducted under 14 CFR Part 91. The student pilot was practicing solo takeoffs and landings to Runway 01 at 21N. He stated: "During the second landing and as I approached the runway I experienced gusty winds. I touched down on the main gears however I could not keep the aircraft in a straight line and lost control over it." According to the certified flight instructor, the student pilot had completed three solo flights before the accident flight. The student pilot had approximately 40 hours of flight experience. While landing, the airplane veered off the left side of the runway, and struck shrubbery. The flight instructor further stated that he included a 10-knot wind restriction when he endorsed the student pilot's logbook for solo privileges. When asked about the wind conditions, the flight instructor stated that he did not obtain a weather briefing, and wind conditions were not reported at 21N. However, the wind socks indicated the wind was less than 10 knots. Examination of the wreckage by a Federal Aviation Administration Inspector did not reveal any pre-impact mechanical malfunctions, nor did the student pilot report any. At an airport approximately 10 miles southwest of the accident site, at 1553, the reported winds were from 350 degrees at 18 knots, gusting to 23 knots.