Aerospatiale AS350BA N611TC incident near Johnson Valley, California

Probable cause

the failure of the small UAS remote pilot to give way to the helicopter, resulting in an inflight collision.

Contributing to the incident was the sUAS remote pilot’s failure to assess and mitigate the risks of operations in close proximity to other aircraft. Also contributing to the incident was the lack of inclusion of the sUAS operations as a part of the aviation activity and risk mitigation.

NTSB analysis

The helicopter was operating under the provisions of 14 CFR Part 91, with an FAA certificate of authorization or waiver to 91.119 (minimum altitudes) to provide videography of an off-road race, under visual flight rules, within Class G airspace in a remote and unpopulated area. The small unmanned aircraft system (sUAS) was operated under the provisions of 14 CFR Part 107, for the same purpose.

The sUAS pilot knew helicopters were operating in close proximity to his position as he was closely following one of the race competitors. Review of video logs indicate the incident helicopter was clearly in view in the sUAS telemetry, however, the remote pilot continued to follow the race vehicle. The remote pilot did not use the service of a visual observer to assist with avoidance of other air traffic.

The helicopter pilot avoided the sUAS, and assumed he was far enough away, when he returned to the racecourse. The sUAS, continuing to follow the racecourse, struck the helicopter on the right side of the windscreen.

Maps of the race layout were provided to the helicopter pilots, but not the sUAS remote pilots, who were also not included in a pre-race organizational meeting for the helicopter pilots. Locations of the remote pilots on the maps were for general orientation, and there was no procedure to provide any sort of separation between the helicopters and sUAS, nor were the sUAS pilots monitoring the helicopter air-to-air frequency.

14 CFR 107.37 Operation near aircraft; right-of-way rules. States that

(a) Each small unmanned aircraft must yield the right of way to all aircraft,

and

(b) No person may operate a small unmanned aircraft so close to another aircraft as to create a collision hazard.

The nature of the race videography brings the aircraft into close proximity with each other. There did not appear to be an appreciation by the race organizers or the sUAS remote pilot of the significance of the sUAS operations as a collision risk to be mitigated. Such tools as defined operating areas, the use of visual observer(s), and/or specified wave-off criteria could have been used to help reduce the risk. Although the race organizers could have provided such an operating framework, it is also incumbent on the certificated remote pilot in command to understand the risks of this operation.

Text from the NTSB. Open the NTSB docket for DCA20IA081 for the full record.