Airport Drone Mitigation Prequel: Why Mitigating the Increase in Rogue Drone Activity in the Vicinity of Airports Has Been Such a Hard Nut to Crack – Until Now?

July 28, 2022 | Mark Rutherford

Drone Proliferation: The Good, the Bad, and the Dangerous

In 2020, the total number of consumer drone shipments worldwide was around five million units. This number is expected to increase over the next decade, reaching 9.6 million consumer drone unit shipments by 2030. We can’t stop drones from being used for pleasure or business, and we shouldn’t attempt to discourage this either. They have their place in society and they’re improving the efficiency of operations and speed of response to incidents. We must learn to live with drones and to accept that the vast majority are being flown correctly and their pilots comply with the law. However, some people won’t abide by the law, and with such exponential sales, it’s no wonder they’re becoming a real nuisance to airports and air travel. Drone proliferation means the threat from drone misuse – whether intentional or not – can only increase.

Security Risk to Air Travel

Some nefarious individuals could acquire drones for malicious reasons, such as intentional collision with an aircraft in flight, deliberately attacking an airport’s infrastructure like the control tower, fuel farm, etc., or intentionally disrupting and halting airport operations by simply flying into their controlled airspace. To deal with these threats, an airport’s Risk Advisory Group (RAG) conducts risk assessments. In its simplest form, we can calculate the risk using this formula:


VULNERABILITY– Airports are vulnerable to deliberate attacks because they may not have deployed a Counter-Unmanned Aircraft System (C-UAS) solution yet, or one capable of ‘automatically’ detecting, tracking, identifying friend or foe drones accurately, then mitigating the drone (removing it) before it’s too late.

THREAT – With incidents and sightings on the rise, the threat is clearly increasing. However, one could argue an airport doesn’t urgently need C-UAS, as the immediate threat may not be readily apparent. For example, a given airport’s RAG may deem it to be low because airports are generally not being actively attacked (e.g., in the UK) – since if they were being attacked it would obviously be headline news.

RISK – Using our formula to deduce the risk, we find that while there is vulnerability, the threat may not be fully apparent or mature and as such, a given airport’s RAG may identify the drone risk as low when reporting to the airport’s Security Executive Group (SEG). The SEG has the responsibility for making decisions on what security equipment is required and, based on the ‘Security’ risk alone, they may choose not to acquire anything. But consider that it’s not only a ‘Security’ risk, but that it’s a Flight Safety risk as well, and this changes everything…

Flight Safety Risk to Air Travel

We’ve discussed the security risk which deals with deliberate acts, but we must also look at the flight safety risk, which deals with accidents and incidents. The threat isn’t just from those wishing to use a drone to cause a ‘deliberate’ act resulting in a security risk to an aircraft or airport. Most drone incursions which occur in controlled airspace and pose a risk to air travel are not deliberate acts of terrorism, protest, or disruption. Whether the drone pilot has made a ‘genuine mistake’ in their choice of airspace to fly, or they’re ‘flouting the law’ to get cool imagery because they believe they won’t be caught, or they’re deliberately ‘breaking the law’ and really don’t care, the flight safety risk they pose to aircrew and passengers is high and on the increase. It is no longer just a low-security risk, but a high safety risk.

Flight safety is sacrosanct and to put flight crews and passengers at risk when there’s a clear threat (and a solution!) is not palatable.

‘Near Misses’ with Drones in Controlled Airspace are on the Increase

D-Fend Solutions’ Drone Incident Tracker lists many openly reported drone incidents around the world. It’s now possible for airport security and safety executives to look at their country or region to establish the facts and understand why a C-UAS solution is essential for a safer airspace. For example, from January to July 2022, there has been over 50 publicly reported near misses between drones and aircraft in flight around the world. What we should also bear in mind is that for every openly reported incident there will be many more that go unreported.

The Threats to Airports Originate from Afar

Most drone incidents occurring all over the world and recorded ‘at airports’ are seldom within the airport boundary. An airport has an airport boundary with controlled airspace extending directly above it, but with several aircraft flying in and out of the airport at once, there are different altitudes of controlled airspace extending several miles away from the airport, all within drone altitude reach. An airport’s Air Traffic Control (ATC) is responsible for controlling aircraft in this airspace, but their radar systems are only designed to detect large airborne objects. Due to the small size of the commercial drones purchased off-the-shelf and DIY drones built at home, they only need to be a couple of kilometers away to render the airport helpless in positively detecting, tracking, and identifying the drone, and more importantly, leaving them with nothing they can do to effectively mitigate it.

Why is it so Difficult to Reduce the Security and Flight Risk from Drones in Controlled Airspace?

To defeat a drone, you first must detect and track the drone. ATC and military radar systems rely on a typical ‘ping pong’ radar return to detect an aircraft-type object. Due to the tiny size of most drones, traditional systems fail to detect the drone at any reasonable range. If they were to dial the sensitivity down to detect smaller objects, it would create a whole host of issues; imagine the false alarm rate if every passing pigeon was detected as a potential threat! One way to overcome the false positives is to integrate an optical camera with the radar, which can enable identification of the drone. Again, even with some of the most sophisticated cameras, the minuscule size of a drone makes visual acuity at range extremely difficult. In addition, the camera is blind when there is poor visibility due to weather or low light. Another option to support radar is a thermal camera such as ‘forward-looking infrared’ (FLIR) but small drones don’t use an engine and emit little heat, so they are largely undetectable at any range. There are other methods of detection, such as acoustics and Radio Frequency (RF) detectors, but they too have severe limitations with background noise. While they may be able to tell you a drone is out there, even with multiple detectors and smart algorithms to direction find, identifying exactly where the drone is can be difficult at best. DJI (the world’s leading drone manufacturer) have a drone fence system called Aeroscope, but it’s only able to detect DJI drones and does not conduct any mitigation whatsoever.

When a Radar Detects and Identifies a Drone

Let’s say, for argument’s sake, that an airport has a really smart layered C-UAS detection solution, active during daylight hours, with no adverse weather and good visibility – the radar detects something it believes is a drone and employs the optical camera which identifies a drone operating 3 km away on the approach flight path. What now? There are a few ways to address the risk, but some of these anti-drone technologies impose restrictions on the airport’s ability to operate:

  • Jamming – Jamming causes interference to many different systems in the airport and the aircraft. Some systems must be switched off to prevent damage, and the aircraft can’t continue to operate. When jamming occurs, the drone may lose control of itself causing further issues. Also, if the drone operator has configured the home location of the drone to be the airport, once the jamming starts and it loses signal with the pilot, the return home command may be executed and the drone will fly to the airport, making jamming counterproductive. Persistent and sporadic rogue drones can keep the airport closed and flights halted for hours or days. Jamming at an airfield is certainly not a viable mitigation technique.
  • Effectors – Effectors are local and normally handheld. They’re relatively cheap, but operators must get close to the drone to use them. It’s not a rapid or guaranteed solution as drones are agile and move quickly, and the process can often descend into a lengthy “cat-and-mouse” game. Even when they are effective, there is still risk of the drone crashing out of control. Effectors have their place for point protection, but less so at an airport with a sprawling boundary of several kilometers and long departure and approach flight paths.
  • Kill or Capture – Kinetic solutions, where something is fired at the drone to take it out, are an extreme measure and would only be used as a last resort, if ever at all – what goes up must come down somewhere. Attempting to capture the drone is the most haphazard method of all solutions with little chance of success. Killing or capturing a drone is not a viable option for airports, as everything must stop for this solution to be employed.

To add to all of this, now consider the size of an airport and the airspace above it, and the size of the airspace required when you calculate the departure and approach flight paths – it’s huge! Sheer size is one of the serious issues facing those who plan to mitigate the drone threat quickly and effectively without disruption to air operations.

Hopefully, you’ll now appreciate why it’s so difficult to reduce the risk – detection and tracking is difficult, identification can be extremely difficult, and mitigating the risk by removing the drone has been almost impossible so far.

C-UAS Has Been Costly and Limited

Imagine owning and running an airport with so much real estate and airspace. How on earth does the SEG even manage to get approval to procure a C-UAS system when a traditional counter-drone solution costs multi-million pounds/dollars and, as we’ve just seen, it’s not even guaranteed to work?! Every spend must be justified, and not being able to remove the drone threat automatically will result in the decision-makers refusing the purchase as it’s cost prohibitive. This is one reason why airports have not been buying C-UAS solutions – until now …

Dare to Imagine That the Next-Generation C-UAS Solution is Here

Forget radars and jammers, forget cameras and kinetic solutions, forget basic direction finding and triangulation through RF and acoustic detectors. Yes, they play a part in a layered C-UAS solution for airports, but they’re expensive and they’re not great when it comes to countering small, commercially available drones.

The next-generation of C-UAS belongs to the cyber age. Cyber Detect, Track and Identify is now possible – Imagine if you had a cyber-C-UAS solution that passively listens to the drone’s RF signal, and is able to interpret it so you know exactly what type of drone it is, whether it’s your drone or a rogue drone, where it took off from, where the pilot is with accuracy, where the drone is (also with accuracy!), what height it’s at, which way it’s pointing, where it’s been and where it’s heading.

Now stretch your imagination further to embrace cyber take-over, approved, compliant, and performed by authorized personnel. Imagine having a cyber-C-UAS solution that’s so smart, it’s able to send a small transmission into the rogue drone to disconnect it from the pilot, take complete control, put the drone into hover to prevent it from crashing into anything, then automatically re-route the drone at a safe altitude, along a safe corridor, to a safe landing point of your choice. At the same time, the system permits all friendly drones to continue operating freely.

Dare to imagine being able to continue flight operations without interference, because you’ve taken control of the threat, or multiple threats, within seconds, rendering it a ‘No-Threat.’ EnforceAir by D-Fend is exactly that cyber-C-UAS solution. It’s here, it’s operational, it’s trusted to protect airports, it’s affordable and it works.

To Take Control of the Drone is to Control the Threat

Having explained why mitigating a drone in the vicinity of an airport is such a hard nut to crack and the only real solution is a cyber solution, in the next few months I will focus on the trilogy of mitigation solutions discussed and dismissed in this blog – jamming, effectors, and hard kill and capture. The first part of this trilogy is a series of blog that digs into jamming. Check the first part, which explains “What is Jamming and How Does it Work?” 

Mark brings a vast amount of business and operational expertise, focusing on engaging with airports, critical national infrastructure, and those owning or managing estates and facilities, where the threat from drones/UAS poses a real risk. Mark delivers high quality and reliability to D-Fend’s customers and partners, educating the market about the need for the most advanced solution for safer airspace.

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