London Gatwick Airport operated smoothly on Sunday, but the fleeting drone operators who led inbound and outbound flights for several days were still large – and a potential threat – after police cleared two local residents who were arrested as suspects.
The Sussex police were hopeless that they had stopped the disturbing and costly drone breaks during one of the heaviest travel periods of the year with Friday's arrests of a couple living near the airport. But they were released Sunday, and the police said they were no longer suspected.
Thousands of passengers suffered from long flight delays or were stranded by cancellations after two drones were reported over the Gatwick airport on Wednesday evening, immediate suspension of all air traffic.
Jason Tingley, Sussex chief scientist, said on Sunday that he could not rule out new drone activity in Gatwick or other UK airports. He also said that it was possible that witnesses who reported observations after the first alarmed alarms were incorrect.
"Of course, it's a possibility. We're working with people who say they've seen something," Tingley told the BBC. 19659002] At the same time, he said police were progressing in a three-part survey: stakeholder tracing, investigation of 67 reported drone observations, and investigation of an injured drone found near Gatwick.
Drone in police hands can provide useful forensic traces, such as DNA from people who handled it, Tingley said. But the rain in the London area had on Friday and Saturday washed away some evidence, he said.
The airport authorities consider drones a danger because they can damage an aircraft in flight or be sucked into a plane's engine, leading to a fatal crash.
After the closure was extended to Thursday, increased military protection was taken on Thursday night to look for more drones while the planes resumed departure and landing at Britain's second busiest airport.
The government has kept the details of security operationally secret, but military equipment is believed to offer better tracking features and give authorities early warning of drones approaching Gatwick, located 30 miles (45 kilometers) south of London.
At the airport on Sunday, the aircraft's arrival and departure connections showed fewer delays than on Saturday. Additional tracking equipment at the perimeter's perimeter and an increased police presence were the only obvious signs of headaches experienced there over the past four days. But officials have strengthened the monitoring of the surrounding airspace behind the scenes.
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British Tr Minister Chris Grayling has said the unspecified "military action" has strengthened trust that the airport will be able to remain open without further disturbance. But anti-drone technology is a relatively new, incomplete field, Grayling says.
It is not clear how officials will respond if another drone gets too close. The best guide might be what happened on Friday night when the airport was shut down for 70 minutes after a drone was discovered. The military distribution allowed the airport to reopen relatively quickly, the authorities have said.
No confirmed drone break-in has occurred since then – a factor that led many to assume the police, had found the responsible operators when they arrested the two suspects Friday night.
That hope ended Sunday when the couple – a 47-year-old man and a 54-year-old woman – were allowed to return to their home in Crawley, a 5-minute drive from Gatwick.
Detective Tingley said he was happy the two were not involved. He hopes a tip will give an important lead.
Tingley said the police did not identify the suspects, but The Mail on Sunday tabloid called them and published a major cover of them headed "Are These the Morons Who Ruined Christmas?"
The crisis in Gatwick first marked drones caused persistent disturbances at a large airport. There is not much data on the dangers of drones for aircraft because they are a relatively new phenomenon.
The police say that the motive of the burglary is not yet known, but they do not think it is "terror-related".  Gatwick Airport, which handles about 43 million passengers a year, has offered a £ 50,000 reward ($ 63,000) through Crimestoppers for information leading to the arrest and conviction of drone operators.