On May 21, 2018, about 1230 central daylight time, a white Ryan Navion N4356K, and a green North American Navion, N8995H, collided in midair near the Walker County Airport-Bevill Field (JFX), Jasper, Alabama. The white Navion's airline transport pilot and passenger were uninjured. The green Navion's private pilot was uninjured. The white Navion sustained substantial damage to the right wing. The green Navion sustained minor damage to the propeller and the underside of the left wing. Both airplanes were privately owned and operated by the pilots as a Title 14 Code of Federal Regulations Part 91 personal formation flight of four airplanes. Visual meteorological conditions prevailed at the time and no flight plans were filed by either pilot. The formation flight originated from Abernathy Field Airport (GZS) Pulaski, Tennessee, about 1130 destined for JFX. Both airplanes were part of a formation flight of four airplanes practicing for an upcoming airshow. All the pilots in the formation had been briefed by the lead pilot prior to takeoff and included instructions for formation changes. Upon arrival to the destination airport, the flight was in a finger-four, heavy left formation, see figure 1a. The lead airplane was in the #1 position. The green Navion was in the #2 position. The white Navion was in the #3 position and the last airplane was in the #4 position. The white Navion's pilot reported that when they were about five miles north of JFX, with "two airplanes" length separation of approximately 80 ft, the lead pilot called for the flight to maneuver to "parade" and the flight closed separation to approximately 40 ft. The lead pilot then called for the flight to change to an echelon right formation, see figure 1b. The pilot of the white Navion stated that he initiated a right bank and descended and decelerated to pass below and behind the green Navion, however due to sun glare he lost sight of the green Navion. He asked his passenger if she could see the green Navion. She told him it was right above them. He immediately pushed the nose down when the collision occurred. The pilot in the #4 position stated it initially appeared the white Navion was not low enough to pass underneath the green Navion. He thought to transmit a warning to the pilot of the white Navion but changed his mind when he saw the airplane had clearance. He further stated just as the white Navion passed underneath the green Navion, the white Navion climbed into the green Navion. After the collision, all four airplanes continued to JFX and landed without further incident.