The Challenges of Explosive Detection

The Evolving Challenges for Explosive
Detection in the Aviation Sector and Beyond
By Robert Liscouski and William McGann
MAY 2016 CTC SENTINEL 1
The mid-air bombing of a Somali passenger jet in February
was a wake-up call for security agencies and those
working in the field of explosive detection. It was also a
reminder that terrorist groups from Yemen to Syria to
East Africa continue to explore innovative ways to get
bombs onto passenger jets by trying to beat detection
systems or recruit insiders. The layered state-of-the-art
detection systems that are now in place at most airports
in the developed world make it very hard for terrorists
to sneak bombs onto planes, but the international aviation
sector remains vulnerable because many airports
in the developing world either have not deployed these
technologies or have not provided rigorous training for
operators. Technologies and security measures will need
to improve to stay one step ahead of innovative terrorists.
Given the pattern of recent Islamic State attacks, there is
a strong argument for extending state-of-the-art explosive
detection systems beyond the aviation sector to locations
such as sports arenas and music venues.
On February 2, 2016, two workers at Mogadishu’s
international airport passed through security after
placing a laptop a on the screening belt at an X-ray
checkpoint. Their colleagues manning the X-ray
machine had no idea the men had been recruited
by the terrorist group al-Shabaab, and they failed to detect the exa
U.S. government sources confirmed to the authors in April 2016 that the
device was concealed in a laptop.
Robert Liscouski has more than 30 years of experience as a senior
government official, business leader, entrepreneur, special agent,
and law enforcement officer. In 2003, he was appointed by President
George W. Bush as the first Assistant Secretary for Infrastructure
Protection at the U.S. Department of Homeland Security. He
currently serves as president of Implant Sciences Corporation, an
American company developing explosive detection equipment.
Dr. William McGann is the chief executive officer of Implant
Sciences Corporation. He was one of the original developers of
commercial ion mobility spectrometry technology for explosives
trace detection (ETD), and he has authored over 70 research proposals
to the U.S. government, 20-plus scientific publications, and
over 25 patents in the areas of nuclear, chemical, and biological
detection technologies.
plosive device hidden inside the laptop. Once safely through to the
boarding gates at the terminal, the terrorist operatives handed the
laptop to a Somali accomplice named Abdullahi Abdisalam Borleh
who had been rerouted onto Daallo Airlines Flight 159 to Djibouti
at the last minute after the Turkish airlines flight he was meant to
take was canceled. Twenty minutes into the flight, the laptop exploded,
blowing a large hole in the fuselage. Borleh was sucked out
of the plane. Only the fact that the plane had yet to reach cruising
altitude, and thus a high pressure differential between the air inside
the cabin and outside, likely saved the lives of the more than 70
passengers on board. The pilots were able to make an emergency
landing back at the airport. 1
But the attack on Daallo Airlines Flight 159 set off alarm bells
within the U.S. aviation security community because it demonstrated
terrorists’ continued determination to use complex methods to
attack passenger jets. A source close to the investigation told CNN
the laptop bomb was “sophisticated.” 2 Security agencies have been
particularly attuned to the threat of terrorists concealing explosives
in laptops or other electronics ever since 2014 when intelligence
indicated al-Qa`ida’s Khorasan outfit in Syria was developing these
techniques, b so al-Shabaab’s success in sneaking a device onboard
a passenger jet was especially alarming. Coming just months after
an EgyptAir mechanic allegedly helped smuggle a bomb onboard
Metrojet Flight 9268 at Sharm el-Sheikh airport killing 224, it also
compounded concerns about the “insider threat” at airports. 3 One
line of inquiry for investigators in the Somali plane bomb attack
should be whether the two Mogadishu airport workers received less
scrutiny by the security staff operating the X-ray machines. 4
This article examines the high-stakes contest between terrorists
developing new techniques to try to beat airport security and
the security officials and technologists working to keep bombs off
planes. Ever since the al-Qa`ida in the Arabian Peninsula (AQAP)
operative Umar Farouk Abdulmutallab, the so-called “underwear
bomber,” came close to blowing up Northwest Airlines Flight 253
over Detroit with a PETN explosive device built by the skillful Saudi
bomb maker Ibrahim al-Asiri, there has been heightened concern
about the terrorist threat to passenger jets as well as the development
and proliferation of advanced bomb-making techniques. But
despite a media narrative of terrorists developing “undetectable
bombs,” this article will explain why from a technological point of
view it is very difficult to beat the latest generation of machines
and scanners, including explosive trace detection (ETD), especially
when these are combined as part of a “layered” approach to security.
b
In the summer of 2014 the TSA mandated new measures at certain
overseas airports with flights to the United States to protect against
explosives being concealed in electronics after intelligence suggested the
so-called Khorasan group in Syria was developing such techniques. See
“Aviation Official: Khorasan Group a threat to flights,” Associated Press,
September 27, 2014.