Airport operators around the world are struggling to contain threats from drones to airspace and operations in the face of confusing laws and policies, as police and security agencies step up efforts to define and deploy counter-drone systems.
“Drones are becoming less expensive while the technology behind them continues to develop rapidly,” said Jürgen Stock, secretary-general of the international police agency Interpol. In September 2021, it collaborated on a major counter-drone exercise at Oslo, Norway’s international airport. “We are seeing an increase in their use not only recreationally and commercially but also for criminal purposes. Inevitably, this has given rise to serious challenges for the law enforcement community globally.”
Airports face a host of hurdles in addressing that threat. Lines of responsibility are unclear for dealing with rogue drones. Also, there is a good chance that anything airports do to fend off a drone attack would be illegal.
“While regulations are slowly catching up to technological advances, there is still a significant gap, and airports have few places to turn for resources to prepare for UAS threats,” the National Safe Skies Alliance wrote in its September 2021 “Airport Response to Unmanned Aircraft System (UAS) Threats.” A non-profit, FAA-funded organization, the alliance works with airports, government, and industry to foster a safe, effective aviation security system.
Technologies are available to counter drone incursions. They include acoustic and optical sensors, lasers, lidar and radar, radio-frequency scanners, thermal and video cameras, and energy guns that can disrupt drone electronics. Some security vendors propose to intercept a drone’s communications link, take it over and command the drone to the ground.
“They have been around for years,” Jonathan Rupprecht, a Palm Beach Gardens, Florida, aviation lawyer, wrote in an August 13, 2021, blog post. “But the issue is how to use them legally outside of a warzone.” A commercial pilot and flight instructor, Rupprecht’s practice focuses in part on drone law.
Legal hurdles for U.S. airports include laws that largely limit counter-drone powers to four federal agencies (the Defense, Energy, Homeland Security and Justice departments), that prohibit unauthorized interception and recording of communications (like that used to control a drone), and that guarantee the right to transit navigable airspace. U.S. law also generally prohibits interference with use of the radio spectrum and outlaws anything other than certified, authorized signal jammers.
Holders of U.S. airport operator certificates are responsible for protecting navigational aids. They would have to ensure no interference by any counter-drone detection technology they might adopt. An operator is required to notify the FAA of any proposed structure or electromagnetic signals that might create a navigation hazard: this is to allow the FAA to study the proposal’s effects. If an operator accepts a federal airport development grant, it is obligated to operate airport facilities safely and efficiently, which would require ensuring that installation of any drone detection system would not create a hazard.
Those are just a handful of the considerations outlined in an August 2020 federal advisory on the application of laws to “the acquisition and use of technology to detect and mitigate” drones. It was issued jointly by the FAA, Justice, Homeland Security, and the Federal Communications Commission.
The advisory doesn’t address the multitude of state and local laws that airports face or address the liability issues that might arise if a drone were brought down by an airport-backed countermeasure.
In counter-drone discussions with airports, federal officials point to state and local police agencies as the first line of response. But police agencies face similar legal hurdles. The main response to an incursion often relies on tracking down the transgressing drone operator through eyewitnesses and such means as cell phone videos and security cameras.
The best hope for improving airport drone defenses may be the FAA’s remote drone identification requirement. The rule, which went into effect last April, generally limits operators to flying drones that transmit identification, location, and performance information so people on the ground and other airspace users can receive that data. Implementation is to start next September (although the rule is being challenged in court). It should enable national security agencies, police departments, and other government officials to sort out among the many drones flying those whose operators are complying with the law from those who may be security risks.
Registrations of small drone operators increased by about 8.5 percent, to 1.14 million, from 2019 to 2020, according to the FAA’s latest data. (Small drones weigh more than 0.55 pounds, or 250 grams but less than 55 pounds, or 25 kilograms.) FAA rules only require an operator to register individually as person, not each aircraft owned. The FAA, which assumes an operator may own more than one aircraft, estimates the recreational drone fleet in 2020 at 1.44 million aircraft. That’s a jump from its 2019 forecast of about 1.38 million small recreational drones owned in 2020.
The numbers come from the FAA’s latest 20-year aerospace forecast, released last July. The FAA reports total registrations of drone operators (or, in the case of commercial drones below, aircraft) since registration was mandated Dec. 21, 2015, not the actual operator or aircraft registrations in use for the year.
The agency says the recreational small drone fleet is likely to peak by 2025 at about 1.55 million aircraft, although it may range from 1.4 million to 1.63 million.
FAA rules require a commercial drone operator to register each aircraft. By 2020’s end, it says, more than 488,000 commercial drones were registered since mid-December 2015. (That 27 percent increase from 2019’s total fell short of expectations. Last year, the FAA forecast a 32 percent increase, to 507,000 drones).
The agency expects commercial drone growth to remain high over the next few years. The FAA forecasts the commercial drone fleet likely will increase 1.7 times from 2020’s size by 2025, to about 835,000 aircraft.
The Careless, The Clueless and The Criminal
Small drones fly for many good reasons, from hobby sorties and personal or professional photography to infrastructure surveys and disaster rescue and recovery assessments. Drone industry members speak of transgressing operators as the careless, the clueless and the criminal. Activity among that last group also is increasing.
Advances in drone technology “have found numerous applications and brought multiple benefits to society in general, [but] the potential threat of technology misuse should not be discounted,” said Georgia Lykou, Dimitrios Moustakas and Dimitris Gritzalis, researchers at Greece’s Athens University of Economics & Business. They co-authored a June 2020 paper, “Defending Airports from UAS: A Survey on Cyber-Attacks and Counter-Drone Sensing Technologies”, in the peer-reviewed journal Sensors. “In our research, we have distinguished asymmetric threats” that can exploit small drone capabilities to attack critical infrastructures (including airports) “in an obscure or unusual fashion, providing unfair advantage to the perpetrator.”
They grouped those threats in three categories:
• Spying, tracking points of interest, and unauthorized mapping and surveillance;
• Carrying chemical, radiological, biological, nuclear and explosive payloads, and
• Intercepting wireless networks, breaching computer systems and conducting cyberattacks by hovering or landing on buildings.
Gatwick is the touchstone of counter-drone threat discussions for airport security officials.
Shortly after 9 p.m. on Dec. 19, 2018, a security officer reported seeing two drones over that international airport 29.5 miles (47.5 kilometers) south of central London. Fearing a collision with a passenger jet, the airport closed and suspended all flights. The airport attempted to reopen around midnight. But drones reappeared and it closed again. Gatwick stayed closed through Dec. 21, affecting 1,000 flights and disrupting trips for 140,000 passengers during the peak Christmas travel season.
Such incursions happen regularly. “This problem is occurring every week or every month at least somewhere around the world,” said Christopher Church, an Interpol senior forensic specialist. “A lot of airports don’t even know they have a problem because they don’t have the means to check if there are drones in the area. And to spot a drone that is maybe 200 feet in the air, you need to really be looking for that.”
The U.S. Transportation Security Administration (TSA) said in June 2021 that it had seen a 157 percent increase in drone activity near airports since 2020. Between Jan. 1 and May 9, 2021, 540 drone events were reported to TSA, with 440 occurring near an airport. Of those, 198 were near one of the U.S.’s 30 largest airports. Fifteen caused an aircraft to take evasive action.
Miami Leads Testing
“The UAS threat to airports has increased exponentially over the last several years, which is why it is vital we begin assessing the effectiveness” of technologies to detect, track, and identify (DTI) drones in live airport environments, Jim Bamberger, TSA’s counter-unmanned aerial system capability manager, said in May. He was overseeing tests of those technologies at Miami International Airport and Los Angeles International Airport that began in mid-2021 in coordination with the FAA and other agencies involved in counter-drone work. TSA is looking to expand the tests to other airports.
Miami’s perimeter protection system includes thermal sensors, 360-degree cameras, and infrared illuminators. The DTI equipment allows the airport to gather information about the height, altitude, direction, speed, type, and operator of any unidentified aircraft. Bamberger said the focus is to identify “the non-compliant operator, the criminal operator, or the careless operator” to prevent entry to the airport’s airspace.
TSA chose MIA as the first DTI testbed because of its ongoing perimeter intrusion technology pilot and its strong partnerships with the airport. It selected LAX because of its diverse aviation operations, large number of enplanements, frequency of drone activity, and high passenger volume. A range of security and surveillance technologies, including radar, thermal imaging, and artificial intelligence, is being tested at LAX.
Meanwhile, the FAA has been evaluating technologies and systems for detecting and mitigating potential drone safety risks as part of its Airport Unmanned Aircraft Systems Detection and Mitigation Research Program. Work began in 2020 with evaluations at the FAA’s William J. Hughes Technical Center, adjacent to the Atlantic City International Airport in New Jersey.
On March 2, 2021, the FAA said it will expand those technology and systems evaluations to four airports beyond Atlantic City International. They are Syracuse (New York) Hancock International Airport; Rickenbacker International Airport in Columbus, Ohio; Huntsville (Alabama) International Airport; and Seattle-Tacoma International Airport.
Interpol Steps Up
Interpol has been stepping up its work on drone threats as part of its initiatives to research, develop and implement tools and approaches to fight international crime. Its Innovation Centre, set up in Singapore in 2017, includes a Digital Forensics Lab that works to increase digital forensics capabilities among law enforcement agencies in its 195 member nations. Those agencies’ officers and specialists will be called upon to investigate serious drone incidents at airports.
Annually since 2017, that lab has been organizing Drone Expert Group Meetings, which bring together drone experts in law enforcement, industry, and academia to share information, knowledge, and best practices.
Interpol worked with the Norwegian Police to organize last September’s three-day counter-drone exercise at Oslo’s Gardermoen Airport (see sidebar page 17 for more info). Also collaborating in the exercise were the airport’s owner, Avinor, the Norwegian Communications Authority, Norway’s Civil Aviation Authority, and UAS Norway. Attendees of the event included representatives from European, Israeli and U.S. law enforcement, academia and industry. More than 140 agencies were represented.
The exercise tested and assessed the ability of 17 drone countermeasures to keep an airport environment safe by detecting, tracking and identifying drones and their pilots. The airport was actively operating during the exercise, conducted more than 2,000 flights over the three days. The objective of the exercise, which graded the countermeasures against specific criteria, was to produce results that could be used to create an Interpol Drone Countermeasure Framework. That document is intended as a focal point for collaboration and knowledge-sharing among law enforcement in member countries.
“Member countries face drone threats on a daily basis, and this technology is so new and emerging that they need to understand it better than they currently do,” said Interpol’s Church. “So, we are working with member countries and industry to broaden and improve their knowledge and expertise so that they can select the right solution for the right task.”