One of the busiest airports in the US was forced to ground flights yesterday, after pilots reported drones passing metres from their planes.

Flight crews on two separate planes coming in to land at Newark Liberty International Airport - a major hub serving New Jersey and New York City - contacted air traffic controllers to report seeing a drone at around 5pm local time yesterday afternoon.

The device appeared to be hovering around 3,500ft over Teterboro Airport, a small regional airport around 17 miles away from Newark, according to a Federal Aviation Association spokesman.

Under US law, drone operators must not fly within five miles of an airport without a permit, and are not supposed to fly more than 400ft above the ground.

In one exchange, a pilot is heard telling ground crew the plane avoided collision “by about 30 feet off our right wing”, NBC reports.

“A flight map showed dozens of planes in the air surrounding Newark Airport around 6pm,” says NBC, as incoming planes were ordered to circle the airport while police helicopters investigated the sighting.

By 7pm, service had resumed, although flights to Newark were experiencing delays as the airport attempted to clear the backlog of grounded flights.

Police and aviation officials have opened an investigation into the incident.

In the wake of the pre-Christmas disruption caused by drone sightings at Gatwick Airport, “the issue of drones impacting commercial air traffic has taken on new urgency”, says Reuters.

Passenger Brett Sosnik told the Associated Press that his plane spent around half an hour circling over Newark before finally receiving clearance to land yesterday.

“There’s got to be a way to combat that stuff and not have it affect huge airports with such a little piece of technology,” he said. - theweek.co.uk