Gatwick Airport
They are investing millions to prevent future flight disruption.
The unusual nature of last month's incident has led to calls for knowledge from leading hubs.
Around 1,000 flights were disrupted at the airport.
Sussex police chief constable gave an update about the ongoing investigation on Radio 4's Today programme.
No-one has been charged over chaos at Gatwick Airport last week.
Security minister Ben Wallace said severe punishments would be in store for "reckless" drone operators.
Paul Gait and Elaine Kirk were released without charge amid ongoing mystery surrounding drone sightings at Gatwick airport.
More than 200 people have reported drone sightings.
How the hell did this happen?
