Low Altitude, High Risk

• By Jeffrey Starr
• Jun 01, 2021

Drones present a significant risk to aircraft during takeoffs and landings – low altitude maneuvering – according to an October study from the Canada National Research Council’s Aerospace Research Center. Whether a drone is piloted by a malicious operator or a careless hobbyist, airport safety and security staff are facing a formidable challenge that we can call “low altitude, high risk.”

TAKEOFFS ARE GETTING SHUT DOWN

Following 9/11, airport security was hyperfocused on human threats: shoe bombers, hijackers, terrorists, etc. While this threat unfortunately remains, in more recent years the airspace above and adjacent to airports has also become a massive and vulnerable soft spot that continues to be punctured by unmanned aircraft systems that endanger aircrafts and civilian passengers.

Since the well-publicized event at Gatwick Airport in London during the holiday season of 2018, when reports of rogue drone sightings near the runway sent air traffic at the UK’s second-busiest airport to a screeching halt, a staggering number of similar incidents have been reported around the world.

Airports in cities across the globe, from Dublin to Sydney and Newark, have all grounded aircraft and closed airspace because of rogue drones. There was a frightening near miss in September 2020. An EasyJet plane carrying 186 passengers and traveling at 320 miles per hour just after leaving the Manchester, UK airport, nearly collided with a recklessly piloted drone, according to MSN.

A report by the UK Airprox Board (UKAB), which investigates near misses, rated it as the most dangerous “Category A” incident. This means there was a serious risk of collision.

In an article about the incident, Manchester Evening News noted, “It was one of eight near-misses between aircraft and drones or suspected drones featured in the UKAB’s latest monthly report.” The threat continues to grow globally. Sen. Mike Lee (R-UT) introduced legislation that would enable the departments of Defense, Justice and Homeland Security to collaborate with private companies on counter-small, unmanned aerial system (CsUAS) efforts.

“Drones already benefit this nation in so many ways, and I know Americans will keep coming up with new ways for them to help us,” Lee said. “Unfortunately, there are also those who use this technology for malicious purposes, and law enforcement needs the manpower to counter this threat.”

As drones become more accessible and ever cheaper, the potential risk of a rogue drone disrupting or shutting down airport traffic entirely increases exponentially. For small regional airports without the resources of major global hubs – law enforcement, human security resources, expensive radars, etc. – the threat is even more acute. Autonomous technology that can detect and then handle (or “mitigate”) airborne threats in a safe manner is crucial.

UNDERSTANDING THE THREAT

Drone threats to airports can be broken down into three distinct categories. • Collision • Attack • surveillance or espionage In each case, drones present a high risk at low altitude, because planes have little maneuverability when taking off and landing.

Airport security and safety staff far too often focus on numbers, thinking, “How many types of drones do I have to mitigate against?” As a result, organizations end up getting scrambled. Just like with any other threat, the best strategy is to prioritize and focus.

In this case, long-range, high payload capacity drones pose the most acute threat. Unlike smaller drones, they endanger airports because they can fly far enough to get close to planes and they can carry big payloads, including explosives. Long-range, heavy payload drones are mid- to large-size drones that can fly several miles per trip, with the ability to carry up to 10 pounds/4.5 kilometers, or more. These drones use long distance radio communication protocols to fly long distances, while transmitting telemetry and high-resolution video back to their remote controller.

The long-range drone market is currently dominated by a single vendor, SZ DJI Technology Co., Ltd. (known as DJI), that possesses a large share of the United States and global market share.

Do it yourself (DIY) drones are purchased per individual component and then assembled by the consumer/operator. This enables the operator to obtain the best possible components and to tailor the drone to his or her specific needs. Some DIY drones can travel long distances and are classified as dangerous drones.

Mid- and large-size drones with heavy payload capabilities can do significant damage to aircraft, including shattered windshields, penetration and inhalation hazards, lost optics and the need for emergency landings after impact, according to the Canada National Research Council’s Aerospace Research Center.

At low speeds of around 140 knots, aircraft that collided with drones showed plastic damage and extensive deformation to the aircraft skin, as well as damage to the vessel’s underlying honeycomb structure. At higher speeds of 250 knots, severe deformation of slat curvature, secondary damage to the leading edge, and even penetration of drone debris into the aircraft’s fractured area has been observed.

Consumers, including bad actors, can purchase a long-range, heavy payload drone (off-the-shelf, or DIY) with a 4K camera, a range of more than four miles and decent payload capabilities, along with the ability to hover and automatically avoid obstacles, for about $1,000.

Treating all drones with a generic approach will dilute your defense. Counter-drone strategy should start with understanding accessible drones that present the most significant threat and then calibrating a targeted defense strategy.

THE LIMITATIONS OF TRADITIONAL SOLUTIONS

Traditionally, the defense strategies deployed against drones originated in the military space. When applied to a civilian airport, they are problematic. Airports are sensitive and challenging environments, and traditional counter-drone mitigation technologies, such as jammer-based and using a kinetic approach (physically shooting the drone) could disrupt necessary communication systems or cause collateral damage.

During detection, radars often have trouble as the main counter- drone component differentiating between small drones and other flying objects, such as birds, and they can be complicated to operate. Jamming-based solutions, or hybrid solutions featuring jammers to handle the drone threat, may affect other radio communications, which would pose a huge problem for airports. Additionally, jamming solutions do not provide full control, as drone operators can regain control of the drone once the jamming ceases.

Kinetic counter-drone solutions, which involve shooting down the sUAS, are risky in crowded situations, because they can cause collateral damage. Optical solutions are ineffective without clear line-of-sight.

ENABLING AIRPORTS’ AUTHORIZED DRONES

Airports increasingly use authorized drones to quickly inspect runways, to see if planes have been damaged following a flight, and to surveil the grounds.

To enable these drones to operate freely, without unexpected disruptions, airports will require a counter-drone system that can tag certain drones as “authorized” to fly in certain areas of the airport. This capability is absent from radars, jammers and other traditional detection systems.

THE RIGHT DEPLOYMENT AND ANTENNA

Vast expanses, such as airports, require long-distance counterdrone coverage. This is difficult, in part because most airports contain multiple airfields and large runways, making comprehensive and holistic counter-drone coverage difficult. Some mitigation methods, such as jamming or kinetic methods, are not suitable for airports, as they may disrupt necessary communication systems, or cause collateral damage.

Airport staff are seeking a counter-drone deployment kit designed primarily for stationary, long-range coverage deployments. This requires a dual-sensor solution that can protect spaces such as take-off air corridors, often referred to as obstacle limitation surfaces (OLS). The antenna in a long-range counter-drone con- figuration is the true differentiator. It should be designed for fixed deployment and provide 30° azimuth coverage and 30° elevation, which extends the directional coverage range to long distance. Since the system will be stationary and outdoors, it must be able to operate in extremely hot and cold environments, and withstand precipitation and dust.

Airport personnel sometimes need to shift their counter-drone systems quickly to a different area or airfield, so they require a CsUAS system whose core components can be easily transferred, mounted and configured within a matter of minutes, providing the ability to move anywhere at any time.

CLEAR SKIES AHEAD

A fresh anti-drone approach is needed for airports. One that enables security and safety staff to take complete control of the hostile drogue, or a swarm of hostile drones, to ensure a safe outcome. A cyber-takeover approach involves disconnecting, taking over and then controlling the signals, and sending the rogue drone via a safe route to a safe landing without interfering with other drones and communication signals. Since takeover systems do not rely upon jammers or kinetic technology – they transmit a precise and short signal that takes control of the rogue drone without interfering with other drones and communication signals; they avoid collateral damage, interference, disruption or disturbance. Continuity is preserved as communications, commerce, transportation and everyday life proceed smoothly.

Cyber-takeover systems extract drone identifiers for a classification process. The telemetry signal is decoded to extract the drone position with GPS accuracy. This includes the take-off position near the pilot in real-time, so that law enforcement can be alerted, preventing future airport disruptions. Authorized drones can continue to function without interruption, while the system tracks the rogue drone remote controller position for selected drone communication protocols.

Focusing on the real risk and using the most suitable technology will result in a neutralized threat and the uninterrupted functioning of airports and aircraft. This approach can change the “low altitude, high risk” slogan to “low altitude, lower risk and higher levels of safety, control and continuity.”

This article originally appeared in the May June 2021 issue of Security Today.