Amateur-built RV-6 N788LL and Piper PA-32R-300 N823AG accident near Williston, Florida

Probable cause

The pilots of both airplanes did not maintain an adequate visual lookout to see and avoid each other.

NTSB analysis

The airplanes were both on approach to the destination airport, operating under visual conditions, when they collided about 3 nautical miles southeast of the destination airport. The wreckage of both airplanes came to rest within 100 yards of one another. The Piper was flying on a course to the right of the RV-6’s departure airport. Around the same time, the RV-6 departed, and both airplanes' flight paths nearly paralleled one another as they continued on course to the destination airport. During the next 7 minutes, the Piper made a gradual descent from 5,200 feet mean sea level (msl) to 1,700 feet msl at a ground speed of about 132 knots. The Piper continued on the same heading until about 2 miles before impact, where it made a gradual left turn. The RV-6 (altitudes unknown) continued on the same flight path until about 4 miles before impact, where it began a slow right turn.

The last portion of recorded radar data of the RV-6 and the Piper showed the airplanes were converging on respective true courses of about 328 and 294 degrees. Based upon this radar data, the expected collision angle was calculated to be about 34 degrees. The collision angle between the airplanes was physically determined by measuring the mass intrusion signature of the RV-6's propeller blade into the left wing of the Piper. This signature corresponds to a collision angle of about 44 degrees. Based on this measurement and radar derived ground speeds, the RV-6's convergence angle was calculated to be about 66 degrees right and the Piper’s was 70 degrees left.

Text from the NTSB. Open the NTSB docket for ERA10FA180 for the full record.