During a Phase III inspection of the airplane, the Director of Maintenance for the operator noticed the firewall was damaged. The damage was reported to the nearest Federal Aviation Administration (FAA) Flight Standards District Office, and verified by the FAA. The damage occurred between the Phase II and Phase III inspection. The airplane had flown 48.2 hours since the Phase II inspection. According to the FAA, the damage was a result of a hard landing. The purpose of the flight and composition of the flight crew was not determined. In addition, the date, actual location, and time of the accident were not determined.