Culprits behind the drone chaos at Gatwick Airport had an insight into how the UK airport was reacting to the incident, its head of operations has said.
The rogue operators could either see what was taking place on the runway or they were eavesdropping on radio or internet communications, said Chris Woodroofe, the airport's chief operating officer.
A number of drone sightings last December forced Britain's second-busiest airport to shut down for 33 hours, disrupting 140,000 passengers' journeys.
The chaos continued despite a huge police operation and the army was eventually called to bring the incident under control.
Sussex Police said the possibility that the perpetrators could have included an airport insider is a "credible line" of inquiry.
Speaking to the BBC's Panorama programme, Mr Woodroofe said the disruption caused by the drones was "terrible".
"It was clear that the drone operators had a link into what was going on at the airport", he said.
Mr Woodroofe was the "gold commander" in charge of the airport's response to the incident on 19 and 21 December, which hit 1,000 flights.
He said there was "absolutely nothing" that he would have done differently as the safety of passengers was of paramount concern.
"It was terrible that 140,000 people's journeys were disrupted, but everyone was safe." Mr Woodroofe said.
Military anti-drone equipment, which can detect the flying machines and disable them by jamming radio signals, remained at the airport until March.
Both Gatwick and Heathrow airports are investing millions in their own systems to prevent future flight disruption.
"We would know the drone was arriving on site and we'd know where that drone had come from, where it was going to and we'd have a much better chance of catching the perpetrator," Mr Woodroofe said.
"What this incident has demonstrated is that a drone operator with malicious intent can cause serious disruption to airport operations. And it's clear that disruption could be carried over into other industries and other environments."