On December 21, 1996, at 0920 mountain standard time, a Raven S-60A hot air balloon, N4396K, registered to and operated by a private owner, landed hard near Rio Rancho, New Mexico. The balloon was not damaged. The private pilot was not injured, one passenger sustained a minor injury, and the other passenger was seriously injured. Visual meteorological conditions prevailed and a flight plan was not filed for the Title 14 CFR Part 91 personal local flight that originated 1 hour prior to the accident. According to the pilot, at takeoff the surface wind speed was less than 4 knots; however, by the time of landing, the wind speed had increased to 12 to 15 knots. The pilot stated that the "approach was normal with passengers braced for a high speed landing." She further stated that she followed "standard procedure" for a high speed landing and pulled the top out of the balloon at about 15 to 20 feet agl. As the top was pulled, the balloon was "hit by a windshear causing the air to exit faster than normal, and therefore, a hard landing." During the touchdown, one of the passengers, who was a balloon student pilot, broke his arm when he "slipped" and fell against one of the propane tanks. According to the other passenger, who was a commercial balloon pilot, "there was nothing I could observe unusual or threatening to our normal descent in preparation for a landing. The "windshear" seemed to "throw" us straight down." She stated that the passenger who broke his arm "was in the center of the basket and appeared to slide forward while we were dragging to a stop." She further stated that "the impact was not more severe than I have experienced, however, it was hard."