WPR09FA248 · Cessna 172N

A Cessna 172N and a Cessna 310P collided in flight in a common practice area for airwork. A witness was flying on a southerly heading within the immediate area of the collision and noticed a silhouette of an airplane, which appeared to be a Cessna 172 at his 10 to 11 o'clock position. The airplane appeared to be performing maneuvers and making turns in a counter-clockwise direction, followed by a turn in a clockwise direction. The witness stated that he noticed another airplane entering the area from the west, traveling at a high rate of speed on an easterly heading. He added that he was unable to see what kind of airplane it was and only saw a "black object" due to the sun being almost on the horizon. The witness continued to watch both airplanes and noted the fast moving airplane was continuing on an easterly heading while the Cessna 172N was still performing maneuvers on a southerly heading around the same altitude. The witness observed both airplanes collide, disintegrate into small pieces, and fall to the ocean below. Review of recorded radar data revealed that the Cessna 310P was maneuvering within a common practice area about 5 miles south of the shoreline at various altitudes. The data depicted the Cessna 172N on a southerly course at an altitude of 3,000 feet msl while conducting a series of shallow left and right turns prior to performing a left 360-degree turn to a southerly heading. The Cessna 310P was on an easterly heading at an altitude of 3,000 feet msl for about 2 minutes prior to the collision. The radar data depicted the two airplanes converging nearly perpendicular to one another about five miles south of the shoreline. During examination of the recovered wreckage, transfer marks were identified consistent with the radar-derived collision angle. Both airplanes were operating under visual conditions when they collided.

Verbatim NTSB analysis and probable cause from the NTSB dataset