By 3am on Thursday 20 December the drone sightings that had caused Gatwick to suspend all flights the previous evening had tailed off. Chris Woodroofe, the airport’s chief operating officer, and a senior officer from Sussex police decided to re-open the runway. “We thought ‘We’re through it. Whoever it is has had their fun and now they’ve packed up because we haven’t seen them for a while’,” a Gatwick executive recalled.
Staff and vehicles were sent out to inspect the runway before flights resumed. The first planes began to manoeuvre into position. But as they did so, a drone reappeared.
That was the moment that Gatwick’s senior management realised they were facing no mere mischief-maker, but a threat of unprecedented gravity.
The drone operator or operators were evidently eavesdropping on the police or airport communications systems, or had access to the flight radar system, or had seen the movements on the runway. “At that point the level of sophistication of someone who had gone dormant while we were shut, and waited till we were about to re-open and then reappeared, convinced us that they were maliciously intent on disrupting our operations,” the executive said.
The pattern was set for the entire day. Nine times Gatwick tried and failed to resume normal operations, although some 20 police patrols were out searching for the drone operator. “The same pattern repeated itself throughout 20 December where the drone would disappear, we would prepare to reopen and the drone would reappear,” the executive said.
The continuing incursions constituted the most serious drone attack yet suffered by any airport in the world – one that shut Britain’s second biggest airport for 33 hours just five days before Christmas, when tens of thousands of passengers were trying to go home or on holiday for the festive season.
It was a well planned, flawlessly executed assault on a major piece of national infrastructure at a time chosen to cause maximum upheaval. “It was a criminal attack, and a sustained and determined effort to disrupt our operations,” the executive said. “It was a super complex, sophisticated, deliberate attack by someone with extensive knowledge of drones and counter-drone systems,” Richard Gill, founder of a security company called Drone Defence, agreed. “We’d not seen anything like it anywhere in the world.”
It was also a warning that rogue drones now pose a very real danger not just to airports and aircraft, but to all manner of public places and events, and that as yet the government and law enforcement authorities are ill-prepared to counter them. The still greater – if largely unspoken – concern is that bigger drones can easily carry explosives or other lethal payloads.
“This is a new world of new technology, and this new threat is not just limited to airports and aviation,” the Gatwick executive said. “There’s a potential for drone attacks on any crowded area or any infrastructure, and what could the drone be carrying? There’s a national debate to be had about how you protect the country.”
Owen McAree, a drone expert at Liverpool John Moores University, agreed. “It’s absolutely been a wake-up call,” he said of the assault on Gatwick. “It’s a turning point in the government’s response to these kind of things. Rather than a gently-gently approach we need to start thinking about this much more seriously. We need to worry not just about amateurs who don’t necessarily know the rules, or about the deliberate misuse of drones for small-scale things like getting drugs into prisons, but the ability to use them to disrupt critical infrastructure on a massive scale.”
The first drone sightings at Gatwick occurred at 9.03pm on Wednesday 19 December. The Control Centre received calls from, among others, employees returning to a staff car park at the end of their shifts who had spotted the lights of at least one drone flying over the airfield.
Gatwick had suffered minor drone incursions before, so its management followed an established protocol. The security duty manager and his police counterpart swiftly assessed the threat, then ordered the air traffic controllers to suspend all take-offs and landings. Police patrol cars, lights flashing and sirens wailing, were immediately dispatched to two dozen sites around the airport’s perimeter that had been previously identified as places from which people might try to launch a drone.
The airport authorities hoped that a show of force would be enough to frighten the drone operator, or operators, away – as it had when people had foolishly or mischievously flown drones near Gatwick in the past. They hoped in vain. The drone or drones continued to appear over Gatwick the rest of that first evening. By midnight the airport had gone from its bronze to silver to gold threat level, and cancelled or diverted 58 incoming and outgoing flights.
After its first abortive attempt to re-open the airport at 3am Gatwick decided to cancel all flights four hours ahead of time to give its airlines and passengers a measure of clarity and an ability to plan.
The airport log shows that by the end of 20 December there had been a total of 115 drone sightings reported over Gatwick, all but eight of them from police or airport staff who were sufficiently experienced to distinguish the lights of a drone from all the other lights around an airport. Most drones are too small to be detected by airport radar.
The authorities still don’t know whether there was more than one drone, but it seems likely there was: drones have only a limited battery life, and witnesses reported seeing different coloured lights. Nor do they know whether there was more than one operator.
They were unable to establish the make of drone, but it was a heavy-duty commercial model – “not the type of toy drone you get at Argos”, a source said. It was also clear that it, or they, lacked the “geo-fencing” restrictions that most manufacturers build into the software of their drones to prevent them flying over sensitive installations like airports. That suggested the drones were either custom built, a very expensive model that comes without geo-fencing restrictions, or modified to by-pass those restrictions.
The drone or drones flew in no particular pattern. They appeared randomly, all over the airfield, and at varying heights. They would stay for anywhere up to about 15 minutes – long enough to cause disruption but too short a time for the police or airport employees to get a fix on them.
Gatwick’s runway alone is 3km long. Its perimeter is about 10km. Because the airport is so large, and drones can fly so fast and so high, it was impossible to tell where they were coming from or disappearing to. Sussex Police said the incursions were “unprecedented, unpredictable and sustained and happened at all times of day, making it difficult for existing technology to track and identify”.
At some point during that Thursday the police sought authority from the Home Secretary, Sajid Javid, to shoot down the drone or drones, and marksmen arrived at the airport. But they fired no rounds. To take down a small, fast-moving drone would have required an astonishingly good shot, and to attempt to shoot one down in a densely populated environment like an airport was too dangerous.
Inside Gatwick’s two terminals the anger grew exponentially as the disruption continued with no end in sight and no way to stop it. Airport and airline staff had to manage distraught and tearful passengers including wedding parties and a group of disabled children flying to visit Santa Claus in Lapland.
Airside, the executive described “the frustration of waiting for the drone to pop up again and trying to plan an operation without knowing when the incident will be over. We’re used to dealing with incidents and enacting our protocols and creating a plan to recover our operation. If it’s weather-related we broadly know when the weather will be over. But with this one we had no way of knowing how long it would last.”
At approximately 6pm the military arrived – a detachment from the RAF’s 90 Signals Unit, based at RAF Leeming in North Yorkshire, backed up by members of the 14th Signal Regiment (Electronic Warfare) from Pembrokeshire. One source said the detachment was unable to detect any signal between the drone or drones and their operator, suggesting they may have been pre-programmed. Nor could it tell the make of drone from its electronic signature. The Ministry of Defence declined to comment.
By late evening, between 9pm and 10pm, the military had set up a “counter-unmanned aerial vehicle” system on a terminal roof that was capable of tracking and disabling drones.
That was when the sightings finally ended. Gatwick officials doubt that was a coincidence. “If you are sat there and you have got away with it for 24 hours and then the military turns up, you quit while you’re ahead,” said one.
The airport finally reopened at 4am on Friday 21 December. By that time 802 flights had been cancelled or diverted, and 120,000 passengers had been unable to fly.
Drone Defence, the security company, estimated that Gatwick and its stakeholders had lost £50 million. Had the Civil Aviation Authority not declared the shut down an “extraordinary circumstance” – and next time it might not – passengers would have been eligible for an additional £70 million or so in compensation. The policing costs would reach nearly £500,000.
Another measure of the attack’s sophistication is that three months later the authorities still have no idea who mounted it.
A £50,000 reward Gatwick offered through the Crimestoppers programme has generated no plausible leads. Sussex Police, who called in officers from at least five other forces following the incursions, have taken more than 100 statements from key witnesses and made 1,100 door-to-door inquiries in communities around the airport, but to no avail. Having arrested one innocent couple following a tip-off, they now say they are “keeping an open mind about who is responsible and their motives”.
Early speculation centred on environmental protesters, not least because Gatwick is presently consulting the public on a five-year master plan for developing the airport. But there seems little point in staging a protest without advertising the cause, and if the protesters took fright after realising that the outrage they were generating would rebound on them they would surely have stopped much earlier.
The Times quoted Whitehall sources saying the attack may have been an “inside job” carried out by a disgruntled current or former employee. It said the craft was seen swooping past the air traffic control tower, taunting staff by flashing its lights at them, and hiding behind buildings. The perpetrator certainly seemed well acquainted with the airport’s layout, and how to eavesdrop on its communications, but a Sussex police source said that was merely one line of inquiry.
An aviation industry source said it was “most likely someone like those people who hack websites just because they can – someone in the drone community who’s now famous for being the guy that took down Gatwick. It’s very much for the sake of it and for the fame of it in their own small circle.”
The best chance of catching the perpetrator now, the authorities believe, is if they boast of their achievement to friends, or in a pub. Whoever it was, they have certainly been spectacularly successful in drawing attention to the danger posed by drones.
The aviation industry had been acutely aware for some time of the growing threat posed by drones. The international airports serving Chengdu in China, Dubai, Lisbon, Tel Aviv, Delhi, Stockholm, Cork, Wellington and Auckland had all been compelled briefly to suspend their operations because of drones during the previous two years. More than 100 incidents involving drones near British airports were reported last year, up from zero in 2013, and two weeks after the Gatwick attack Heathrow had to halt flights for an hour because of a drone incursion.
There have been no catastrophic collisions between drones and planes to date, but videos on YouTube show alarming images of the considerable damage they could cause if they collided. “Drones have the potential to take out an engine or hit an important piece of the airframe and cause a significant threat to that aircraft,” an expert said.
The Department for Transport was developing measures to counter that threat well before the Gatwick attack, but officials admit it is doing so with far greater urgency now.
“It’s been a wake-up call because drones are quite a new technology and their use has expanded very quickly and whenever you get those kind of situations the regulatory framework has to play catch-up,” said Karen Dee, chief executive of the Airport Operators Association, which represents all Britain’s major commercial airports.
“People knew there was an issue. They were doing work on it, but it was not receiving the sort of attention that it might have done and is receiving now,” said another industry insider.
Since the Gatwick incidents the government has extended to 5km the 1km airport exclusion zone for drones that it established last July. It is introducing new fixed-penalty notices for minor drone offences; increasing police powers to stop and search drone users near airports, and to access electronic data on their drones; mandating the registration of all but the smallest drones; and requiring drone users to take a competence test. It is also exploring whether to make it compulsory for manufacturers to build geo-fencing software into their drones.
Those measures should help deter careless amateurs or thrill seekers from flying drones near airports, but they would hardly prevent a deliberate and malicious attack.
“Whoever was flying at Gatwick was already flying in an area where they were breaking the law, so making that area bigger is not going to stop that happening,” McAree, the Liverpool drone expert, said. Car drivers are registered, he added, but that cannot prevent them driving cars into crowds of people. Another security expert called the measures a bit of “security theatre”, pointing out that the offence of endangering an aircraft already carries a maximum sentence of life imprisonment.
The DfT is also testing various new technologies to disable drones, but Gatwick has not waited for the results of those tests.
It had twice suffered brief shutdowns before last December because of drones and had developed a protocol for responding to them. Last October it war-gamed a simulated drone attack with the police, Department for Transport (DfT) and Centre for the Protection of National Infrastructure (CPNI). For some time it had been trialling systems for tracking and disabling drones but – like other airports – it had refrained from purchasing one. “The perfect system doesn’t yet exist,” a source explained. “What you’re waiting for is a government-approved, licensed system that you can buy and know will work.”
The pre-Christmas drone attacks changed Gatwick’s cost-benefit analysis overnight. Within hours of the last drone sighting on 21 December, the airport swiftly purchased an Anti-Unmanned Aerial Vehicle Defence System (AUDS) developed by a consortium of three British companies including Chess Dynamics, which is based just a few miles away in Horsham. It later bought a second, at a total cost of nearly £5 million for the pair. Those AUDS systems were customised for Gatwick’s use and sources insist that they and other defences now provide the airport with protection as good as that afforded by the RAF.
The AUDS system is one of the best available, according to Dr McAree, and it certainly offers Gatwick far stronger defences than it had before. It has radar that detects a drone incursion, and a sophisticated electro-optical system that tracks the drone once it has been spotted. An inhibitor then takes the drone down using powerful radio waves that jam its GPS system and disrupt its communication signals. The makers of the AUDS system declined interview requests, but they say on their website that it is “the only fully integrated counter-drone system in the world” and can detect and disable a drone up to 10km away within 15 seconds.
However the technology was developed primarily to protect military bases in places like Afghanistan, Iraq and Syria where, in the words of one aviation expert, “you’re shooting at everything outside a base and you don’t give a monkey’s what happens to those things”. Its use to protect civilian airports is more problematic.
First, as the law stands, the airport or police would have to obtain government authorisation to destroy a drone in mid-air with what is essentially a weapon, and to destroy it without knowing where it might fall.
Secondly, the radio waves that the AUDS system uses to disable the drone could also potentially damage the communication, navigation and GPS systems of the airport and its aircraft, as well as walkie-talkies, the internet and mobile telephones. For these reasons the US Federal Aviation Administration has warned American airports against deploying unapproved technology.
A third issue is how smaller airports without Gatwick’s resources would pay for such a system. Of Britain’s 50-odd commercial airports less than half a dozen – Heathrow, Gatwick, Manchester, Stansted and Luton – could afford it.
Gatwick will not discuss how it would use its AUDS system, but the Airport Operators Association is pressing the government to set standards for safe and effective anti-drone technology, together with a regulatory framework to govern its use. That is a tall order, and one that will require collaboration from manufacturers, airports, the police, European aviation authorities and any number of government agencies including the DfT, the Home Office, the Civil Aviation Authority, the CPNI and the communications regulator Ofcom.
In a perverse way the perpetrator of the Gatwick assault may have unintentionally performed a public service, albeit one that caused immense anger and disruption. He, she or they demonstrated that not just airports but almost any open public place, from sporting venues and festivals to streets, stations, oil refineries and beaches, are now vulnerable to attacks by drones and, most alarmingly, by drones that terrorists could use to deliver very nasty payloads.
That is not fear-mongering. Islamic State already uses drones to drop small bombs on targets in Syria and Iraq. Last August Venezuela’s President Nicolas Maduro survived an attack by two drones carrying explosives as he gave a speech in Caracas. At an Abu Dhabi arms fair in February the Kalashnikov Group, which gave the world the AK-47 assault rifle, unveiled a “kamikaze drone” or “poor man’s smart bomb” that is capable of delivering up to 6lb of explosives with pinpoint accuracy.
“Take a $1,000 drone and a $50 hand grenade,” warns Richard Gill of Drone Defence, “and all of a sudden you have a precision strike weapon.”
There are some good, informative drone blogs in the UK. Among them: