CHI06LA157 · Good RV-6A

An amateur-built RV-6A airplane and an amateur-built RV-8 airplane, collided in-flight during an overhead recovery maneuver. The formation flight of four airplanes was arriving prior to an air show. They were scheduled to perform in the air show later that day. The flight leader stated that the flight was established southbound over the approach end of runway 18 when he initiated an overhead recovery for landing. He stated that he pulled up and started a turn to return for landing. He reported that shortly after starting his turn he felt the impact of the other airplane. He was able to maintain control and subsequently landed on runway 36. A ground-based witness reported that the four airplanes flew over his position northbound in a diamond formation at 800 - 1,000 feet above ground level (agl). He noted that the formation appeared "evenly spaced and steady." The formation proceeded to make a descending turn. As the formation was established southbound, about 200 feet agl, the lead airplane executed a climbing left turn away from the other airplanes. Approximately two seconds later the second airplane began a left climbing turn. The witness reported that this airplane "appeared to turn and climb much more aggressively than the lead aircraft." Prior to completion of the turns, the witness stated the second airplane "merged with the lead aircraft from below and from the left." He noted seeing debris separate from the airplanes due to the collision. The second airplane subsequently entered a "near vertical, slow spiral descent in a nose down attitude." Post accident inspection of the RV-6A airplane did not reveal any anomalies associated with a pre impact failure. The pilot of the RV-8 stated that there were no failures or malfunctions with the airplane prior to the accident.

Verbatim NTSB analysis and probable cause from the NTSB dataset