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.”
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)
“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.
• surveillance or espionage
In each case, drones present a high
risk at low altitude, because planes have
little maneuverability when taking off and
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
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
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
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
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.