Cessna 182 N9021X accident near San Juan, Puerto Rico

Probable cause

The pilot's failure to maintain adequate distance from helicopters during the approach for landing, resulting in an encounter with wake turbulence and subsequent loss of control.

NTSB analysis

The private pilot and pilot-rated passenger were approaching the airport for landing during a personal flight; the tower controller cleared the airplane to land behind a flight of two Blackhawk helicopters. The passenger reported that he and the pilot visually acquired the helicopters and were instructed by the controller to perform s-turns for spacing during final approach. As the airplane crossed the runway threshold, the passenger noted that the helicopters were clearing the runway. The airplane then encountered a "heavy downdraft" followed by a "burst" that pitched the airplane to the left. The pilot subsequently initiated a go-around, during which the airplane encountered another "burst," pitched up, rolled inverted, and collided with the ground between the runway and taxiway. The passenger reported that there were no mechanical anomalies with the airplane and that the engine was performing normally. The pilot died in the hospital the day after the accident.

Although the controller cleared the airplane for landing following the helicopters, Federal Aviation Administration guidance on wake turbulence avoidance states that, if a pilot accepts a clearance to visually follow a preceding aircraft, the pilot accepts responsibility for both separation and wake turbulence avoidance. The circumstances of the accident are consistent with the airplane encountering wake turbulence from the landing helicopters, and it is likely that, had the pilot maintained greater separation from the helicopters or conducted a go-around earlier, the airplane would not have encountered the wake vortices that resulted in the loss of control.

Text from the NTSB. Open the NTSB docket for ERA18LA002 for the full record.