Flights have resumed at Britain’s Gatwick Airport following a nightmare 36-hour delay that impacted more than 100,000 holiday travelers – but the drone operator that sparked the chaos has not yet been found, and a government official says its “clearly one possibility” that it was an environmental protest.

The airport resumed operations Friday morning after being closed since Wednesday night, when mystery drones first started appearing around its runway. Over the next day and a half, there were around 40 reported sightings of the drones – the most recent occurring last night around 10 p.m. local time. A report of a new drone sighting Friday afternoon, which temporarily suspended flights once again at Gatwick, was unfounded.

Police have not yet figured out who is flying the drones – or why they are doing so – but are looking at all possible angles in their investigation.


Terrorism has been ruled out, but when asked by Sky News if the drone disruption was an environmental protest, Britain's Transport Secretary Chris Grayling said it was “clearly one possibility” although “we genuinely don't yet know at this moment".

Extinction Rebellion, an environmental activist group that blocked roads in London in November in a bid to demand the British government “tell the truth the about the climate and ecological emergency,” has already denied any involvement in the Gatwick delays.

“We've heard there are rumors circulating,” the group posted on Twitter. “We remind people that our actions are always 'above the ground' meaning we stand by our actions, are accountable and take the consequences.”


Passengers wait to check in at Gatwick Airport on Friday. (AP)

The airport says around 110,000 people had been scheduled to pass through Gatwick on Thursday, but none of the 760 flights made it there.

The British Airline Pilots' Association told Sky News earlier Friday that it was “extremely concerned” about the threat of the drones reappearing now that flights have resumed.

Officials have not said much about the make and model of the drones, except that they appear to meet “industrial specifications,” according to the Associated Press.

And it is not entirely clear what would happen if one managed to collide with an aircraft.

In tests at the University of Dayton in September, a simulation that mimicked a 2.1-pound drone hitting into a commercial plane traveling at 238 mph created “significant damage to the wing”.

Research from a group of universities working in conjunction with the U.S. Federal Aviation Administration also “evaluated the potential impacts of a 2.7-lb. quadcopter and 4 lb. quadcopter; and a 4-lb. and 8-lb. fixed wing drone on a single-aisle commercial transport jet and a business jet.”

But the FAA says in those tests, the “structural damage severity levels ranged from no damage to failure of the primary structure and penetration of the drone into the airframe.”

Ravi Vaidyanathan, a robotics lecturer at London’s Imperial College, told the BBC "the threat posed to larger aircraft by drones is small but not negligible.”

Despite the potential of the drones re-appearing at Gatwick, officials there say they are better prepared to handle them.

"We've got measures in place now where if the drone appears in terms of physical response, in terms of a technical response, we should be in a much better position now to track and capture the drone,” Sussex Police Assistant Chief Constable Steve Barry told Sky News.

Counter-drone equipment is deployed on a rooftop at Gatwick. (AP)

Chris Woodroofe, Gatwick’s chief operating officer, added Friday that “a number of mitigating measures in place provided by a number of government agencies and the military to ensure that I have the confidence to be able to reopen the airport."

Gatwick also says it is “expecting knock-on delays and cancellations to flights” Friday as things get back to normal.

“If you are due to travel from Gatwick today, we strongly recommend that you check the status of your flight with your airline before departing for the airport,” it warned travelers on its website.