On January 30, 1993, about 0745 hours mountain standard time, a Thunder and Colt Airborne America, Colt 160A balloon, N128TC, experienced a hard landing near Chandler, Arizona. The balloon was being operated as a visual flight rules (VFR) local area sightseeing flight under Title 14 CFR Part 91 when the accident occurred. The balloon, registered to and operated by Naturally High Balloon Co. Inc., Phoenix, Arizona, was not damaged. The certificated commercial balloon pilot and 6 passengers were not injured. One passenger received serious injuries. Visual meteorological conditions prevailed. An Operations Inspector, Federal Aviation Administration, Scottsdale Flight Standards District Office, reported that the accident was first reported to his office about June 1, 1993. The injured passenger indicated that during landing, the balloon was bounced along the ground by gusty wind conditions, throwing the passengers into the balloon structure. Following the landing, the injured passenger was transported to a local hospital. The passenger received an ankle and spine injury that prevented the passenger from working for the following 5 months. Medical documentation of the passenger's injuries was received by the FAA. In an interview with the FAA on June 4, 1993, the pilot indicated that he was aware that the passenger was injured; however, was unaware of the severity. The Safety Board's Southwest Regional Office was notified of the accident by FAA personnel on July 22, 1993. On July 23, 1993, the pilot was sent a letter of investigation and a Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2, via certified mail. A return receipt that was received in the regional office on July 28, 1993, indicated that the pilot signed for the pilot/operator report package on July 26, 1993. The pilot did not return the pilot/operator report. An additional letter of investigation, along with another pilot/operator report was sent to the pilot on August 27, 1993, again via certified mail. The second pilot/operator package was received, unopened, in the regional office on September 20, 1993. The U.S. Post Office indicated on the unopened package that delivery was attempted on August 30, 1993; a second notice issued on September 4, 1993; and then returned to the Safety Board on September 13, 1993, as unclaimed. No further communication was received from the pilot. All information concerning the pilot in this report was obtained from a review of FAA records on file in the Airmen and Medical Records Center located in Oklahoma City. The pilot holds a commercial pilot certificate, issued on March 14, 1989, and limited to hot air balloons with an airborne heater. The pilot does not possess a medical certificate, nor is one required for balloon operations; however, the pilot submitted an application for a medical certificate on March 27, 1991. The FAA did not issue a medical certificate; however, the pilot noted on the application that he had accumulated 1,400 hours of aeronautical experience, of which 100 hours were accrued in the previous 6 months.