According to the pilot, the tower controller cautioned for wind shear and then cleared the flight to depart. The pilot delayed momentarily to assess the wind conditions and then departed. The airplane climbed to 75 feet, and then began to lose altitude as if the airplane was "being pushed down." The pilot applied corrective measures but was unable to arrest the descent. The airplane impacted the runway resulting in substantial damage to the airplane. The automated special weather observation report, issued shortly after the time of the accident, reported winds variable from 100 degrees to 160 degrees at 7 knots with light rain.