Amateur-built RV-8 N248DF accident near Reno, Nevada

Probable cause

The other pilot's failure to maintain clearance from the airplane during the line-abreast formation.

NTSB analysis

During the initial start of an air race, nine airplanes were positioned in a line-abreast formation. The RV-8 was positioned in the No. 7 slot, and the GP-4 was right of the RV-8 in the No. 8 slot. The RV-8 pilot reported that, during the race start, he felt an air current push down his airplane. He then moved forward of the No. 6 slot airplane and initiated corrections to reestablish his position within the formation. The GP-4 pilot reported that he saw the RV-8 descend below his airplane's left wing and that he reduced power while initiating a slight right bank in an attempt to "back out" of the formation. The pilot who was in the No. 9 slot reported that he observed the GP-4 move forward back into the formation very quickly. At that time, he noticed the pilot of the GP-4 trying to slow or correct his position to the right using ailerons. Shortly after, the propeller of the GP-4 struck the right aileron of the RV-8. Following the collision, the RV-8 entered an uncommanded left roll; however, the pilot was able to level the airplane and land uneventfully. The GP-4 pilot pitched his airplane upward and rolled right to avoid the surrounding airplanes and was also able to land the airplane uneventfully.

It is likely that, if the pilot of the GP-4 had maintained adequate lateral distance from the RV-8 while advancing forward to maintain a line-abreast formation, he would have been able to maintain clearance from the RV-8 as it descended and would not have needed to bank right, which further reduced the GP-4 pilot's visual contact with the RV-8 and led to the midair collision.

Text from the NTSB. Open the NTSB docket for WPR17LA209 for the full record.