Gatwick Airport closed for 24 hours now as drones keep breaking perimeter

This makes it to the top 3 most interesting news of the year for me. Someone has been able to fly some kind of heavy duty drone over the runway for 24 hours now. They called in the army but not only they can't arrest him, they are unable to stop those incursions too.

He must be flying from several kilometers away and the airport is already expecting disruptions most of tomorrow, so I would argue they already tried a GPS/ISM jammer and it must have been ineffective. Is this guy using some kind of inertial navigation system?

So basically a skilled someone managed to destroy the holidays of hundreds of thousands of people.