On 22 January of this year, it happened again, or did it? A drone was spotted by two pilots approaching Newark Liberty International Airport – one of two international hubs that serve New York City. According to pilot reports, the device was soaring at an altitude of 3500 feet (1066 meters), well above the 400 feet (122 meters) prescribed by current civil aviation code.
Given the recent events on the other shore of the Atlantic – in the UK, Newark’s authority was taking no chances. The runway was closed with flights delayed or diverted, only to be re-opened 90 minutes later after no new drone sightings were reported. It seemed Newark’s mystery drone pilot wasn’t hellbent on causing any further trouble.
But within hours of the initial sighting, naysayers began popping up all over social media and the blogosphere – questioning if there had been a drone at all. As a recent article on the blog DroneDJ noted, even DJI jumped into the fray with the company’s Vice-President of Policy and Legal Affairs calling the sighting “not credible” on his personal Twitter account.
The official DJI account was more cautious in its assessment of the event but urged everyone to keep an open mind while reminding us of all the other times a bat, a balloon or even an airborne plastic bag had been mistaken for a rogue UAV bent on air traffic disruption.
This isn’t the first time a drone sighting has been called into question. Readers may recall that in the heady swirl of confusion over the Gatwick shutdown Detective Chief Superintendent Jason Tingley of Sussex police himself wondered – perhaps a bit too publicly – if the reason his officers couldn’t track down the offending device was that “there may not have been any genuine drone activity in the first place.”
The Sussex Police department was quick to issue a clarification of the Detective’s statement and a British government spokesperson characterized the quote as a miscommunication. Given the multiple witnesses who attest to having seen the UAV hovering over or near the runway, it’s highly likely that the Gatwick Drone was an authentic – and very costly – rogue drone intrusion.
But, why are these intrusions so difficult to pin down? Part of the reason may lie in the instrument used to make and confirm the majority of sightings – the human eye.
Human vision is not particularly well adapted to accurately identifying fast moving objects. A study conducted in 2012 by researchers at the University of Sydney’s school of psychology revealed that the brain sees fast-moving objects by “using blurs or streaks, as seen in photographs.”
Co-author of the paper Professor David Alais added, “The brain doesn’t see instantaneously. It takes about 100 milliseconds for the neurons in the brain to fully encode information.” Thus a quick-moving device like a drone may register as a blur across the field of vision.
While the brain can recognize the general direction of the blur and perhaps some aspects of its color and form, 100% accurate identification of the object in question is difficult. Throw in unfavorable light or weather conditions and certainty becomes even more elusive. Such factors help explain a large number of false UAV sightings in which a half-glimpsed balloon or plastic bag becomes a drone in the mind of the witness – his or her brain is spitting out the “most logical” interpretation of what it didn’t fully understand.
Given that some modified UAV’s can travel at speeds up to 260kmh (163 mph) in optimal conditions, the opposite may also occur. A real drone could be mistaken for a natural object, like a bird, and the threat goes unnoticed. Given the serious danger the hard metal parts and lithium batteries in many drones pose to landing and departing aircraft – such an oversight could be fatal.
And thus, we come to the most important reason accurate identification and investigation of alleged drone threats is so fundamental to the efficient and safe management of an airport: Safety. If an airport authority is aware of all objects in its airspace and able to distinguish between real and false alarms – everyone from administrators to airlines, to pilots to passengers, is safer and freer to go about their business.
But safety alone is only at the top of a very motivating list:
Costs – As any airport authority knows, the price of shutting down a runway – even temporarily – is extremely high. Three separate UAV-related incidents in 2016 alone shut down Dubai International Airport, the world’s 3rd busiest airport by international passenger traffic, with every drone intrusion costing an eyewatering US$1million (875,645€) per minute.
Gatwick was hit by an equally terrifying bill for its nearly 3-day runway closure. According to British press reports, the incident was estimated to have cost the airport authority and airlines over £50million (57millon euros).
With such high financial stakes, shutting down a runway over what turns out to be a free-flying plastic sack or misinterpreted reflection is clearly unacceptable. Airport authorities need to know what is in their airspace, otherwise they and the airlines who depend on their management risk losing millions.
Damaged Reputation – Not to pick on those airports who have suffered a drone intrusion, but it’s not a good look. Gatwick, as well as police and military units called in to find the errant UAV, found themselves the focus of anger and the butt of innumerable internet jokes during the crisis with criticism pouring in from passengers, airlines and government officials alike.
An opinion piece in American news channel Fox News observed acerbically that one tiny drone was managing to hold 100.000 people hostage (In reality over 140.000 passengers were affected) while a former UK Chief of the General Staff and former head of the British Army, Lord Dannatt called the incident a “national embarrassment.” His lordship added, “People in Europe are sniggering at us…and we’ve just given them 36 hours of fun laughing at this pantomime.”
Clearly, having a system in place to reliably distinguish between drones and other airborne objects (as well as the ability to trace any rogue drones and help locate their pilots) would have done much to avoid an embarrassing and demoralizing spectacle.
The ACI (Airports Council International) is an organization created in 1991 by airport operators around the world and cooperates with the International Civil Aviation Organization (ICAO) to: “Defend airports’ positions and develop standards and recommended practices in the areas of safety, security and environment initiatives.”
In January 2019 the ACI released an Advisory Bulletin entitled “Airport Preparedness – Drone related disruption to aircraft operations” in which it urged its members to take proper precautions against drone intrusions and the disruptions they’re liable to cause.
While the ACI advises members to be cautious when examining anti-drone systems, “ensuring that any new anti-drone measures do not create unintended safety hazards and unmitigated risks to other manned aircraft, authorized drones, and aviation infrastructures,” it nevertheless encourages airport authorities to take drone detection and neutralization seriously.
As their Advisory Bulletin pointedly states: “It is incumbent on all industry stakeholders to be prepared to protect the safety and regularity of aircraft operations.”