A September collision between a small civilian drone and a US Army helicopter was caused by the drone operator’s failure to see the helicopter because he was intentionally flying the drone out of visual range, the US National Transportation Safety Board said on Thursday.
The incident between a US Army UH-60M Black Hawk helicopter and a DJI Phantom 4 drone near Staten Island, New York occurred as concerns mount over the rising number of unmanned aircraft in US airspace.
The helicopter landed safely but a 1 1/2–inch (3.8-cm) dent was found on the leading edge of one of its four main rotor blades and parts of the drone were found lodged in its engine oil cooler fan. The Army said previously that the helicopter was not targeted and that it was struck by a drone being operated by a hobbyist.
The helicopter was flying at about 300 feet (90 meters) when the drone struck its side. The helicopter, which was repaired within 24 hours, was in the area to provide security during the United Nations General Assembly.
The drone operator intentionally flew the drone 2.5 miles (4 km) away, well beyond visual line of sight and did not have an adequate understanding of drone regulations, the NTSB said in a report released on Thursday on the incident. Drones are barred from being flown out of visual range.
Government and private-sector officials are concerned that dangerous or even hostile drones could get too close to places like military bases, airports and sports stadiums.
Earlier this year, the US Federal Aviation Administration banned drone flights over 133 US military facilities. The Pentagon said in August that US military bases could shoot down drones that endanger aviation safety or pose other threats.
The FAA began banning drone flights over 10 US landmarks in September, including the Statue of Liberty in New York and Mount Rushmore National Memorial in South Dakota, at the request of national security and law enforcement agencies.
Earlier this year, the FAA and US Interior Department separately barred drone flights within the boundaries of sites including the USS Constitution in Boston, the Gateway Arch in St. Louis and Independence National Historical Park in Philadelphia. The list also includes Glen Canyon Dam in Arizona, Hoover Dam in Nevada and Grand Coulee Dam in Washington state.
The Obama administration implemented rules opening the skies to small drones for education, research and routine commercial use. The Trump administration is considering allowing expanded drone use for purposes such as deliveries, where aircraft would fly beyond the sight of an operator, and in October announced a pilot testing program with states and local communities.