At 13:11, a Cessna Caravan was destroyed during a precautionary landing near Hillsborough and the pilot suffered minor injuries. The airplane had two auxiliary fuel tanks installed in the passenger cabin the day before and the FAA had issued a special flight permit for overweight operations. The airplane was filled with 585 gallons of Jet-A and the gross weight of the airplane was about 10,000 pounds. As the airplane passed through about 800 to 900 feet, the pilot smelled turbine fuel. He stopped the climb and attempted to locate the source of the fumes, but failed. He requested radar vectors to the closest airport and initiated a descent. He then noticed about 1 inch of standing fuel on the floor of the cabin, and turned off the radios. During the descent, the amount of fuel in the cockpit area continued to increase, so the pilot elected to land in an open field rather than continue toward the airport. He reported that due to fuel fumes and raw fuel in the cockpit, his vision was blurred, his eyes burned, and he had difficulty breathing. He positioned the airplane for landing into the wind. On final approach, the fuel was up over his ankles and his sectional charts were floating on top of the fuel. After touchdown, he applied maximum reverse thrust and brakes. The plane hit a ditch, shearing off the nose wheel. The pilot escaped the cabin before a post crash fire erupted that consumed the airplane. The two cabin tanks were mounted such that the fuel takeoffs were not visible to the pilot. The pilot reported that he had not actuated the auxiliary tank system on the flight.