After having trouble maintaining altitude and aligning the airplane with the localizer, the pilot conducted a visual approach for runway 20L. The aircraft touched down, and continued off the end of the runway, striking localizer equipment, which substantially damaged the left wing. No mechanical malfunctions were reported by the pilot or identified post-accident. The recorded winds on the field were calm approximately 15 minutes prior to the accident. The pilot reported he had been ill for several days prior to the accident, and post-accident medical testing revealed he was dehydrated due to the illness. Additionally, the pilot reported he did not eat anything on the day of the accident. The pilot was airborne for approximately 8 hours, including fuel stops and periods of maneuvering due to weather. According to the Federal Aviation Administration, the pilot held a third-class medical certificate with a limitation for his diabetic condition.