Two drones used to shut down Gatwick Airport for 30 hours were flown by people with “detailed knowledge” of the airport, police have said.
A thousand flights were disrupted during the standstill, affecting more than 140,000 passengers over three days in the busy Christmas period, with the incident beginning shortly after 9pm on December 19, 2018.
Assistant Chief Constable Dave Miller, head of operations command, said police had carried out an “exhaustive” criminal investigation. However, with no new information there would be “no further realistic lines of enquiry at this time.”
Police have ruled out terrorist links, and have also said there is no evidence to support the theory the operation was state-sponsored or led by a campaign group.
Sussex Police said they have received 129 separate sightings of drone activity, with 109 of those from “credible” witnesses such as a pilot, airport workers, and airport police.
Two people were arrested during a police operation which cost £790,000, involving 96 people of interest during house-to-house inquiries covering 1,200 properties and 222 witness statements.
The suspects were later released without charge or any further action, and no further arrests have been made.
A force spokesperson confirmed that witness statements had made it possible to ascertain that “at least” two drones were in operation and “the offender, or multiple offenders, had detailed knowledge of the airport.”
They said: “Witness statements show activity happened in ‘groupings’ across the three days on 12 separate occasions, varying in length from between seven and 45 minutes.
“On six of these occasions, witnesses clearly saw two drones operating simultaneously.”
Miller described the incident as a “serious and deliberate criminal act”, specifically designed to endanger the safety of passengers.
He said: “A drone strike can cause significant damage to an aircraft in flight, and it is important to emphasise that public safety was always at the forefront of our response. No aircraft was damaged or passenger injured.
“This was an unprecedented set of circumstances for all agencies involved at a time when the police and the government were at the early stages of assessing domestic counter-drone technology.
“Equipment was quickly installed using both military and private assets to bring it to a conclusion and allow the airport to reopen. Measures now available have strengthened our capability to respond to and investigate a similar incident in the future.”
The police operation required resources from seven UK police forces as well as national expertise, and Sussex Police is involved in sharing learning from the incident with police and agencies from across the UK and internationally.