At 1250 central time, an amateur-built Vans RV-8 suffered a loss of control and crashed near Van, Texas. The pilot and passenger were killed. The airplane was one of four airplanes that departed as a formation flight from Gilmer Municipal Airport. Prior to departure, the lead pilot obtained weather and discussed formation procedures with the other pilots, including lost sight procedures. The accident airplane flew in the number two slot, 45 degrees behind the left wing of the lead airplane. The remaining two airplanes were to the right of the lead. The formation flight encountered unexpected clouds, which they elected to climb to avoid. During the climb, the visibility deteriorated and the flight flew into a sudden heavy rain. The flight lead advised the other pilots to execute the previously discussed lost sight procedures. Three of the airplanes landed uneventfully at other airports. Ground witnesses described the accident airplane as flying with fluttering wings and reported that the aircraft engine was cutting in and out before the airplane suddenly dove into the ground. The weather at the time of the accident was described by a witness as very low clouds and poor visibility.