September 11 changed aviation security forever. Will coronavirus, bioterrorism and technology fuel new threats?

The deadly terrorist attacks against the United States on September 11, 2001, prompted an outcry from around the world: "We are all Americans." Washington's policies realigned around fighting terrorism and bilateral relationships strengthened or crumbled depending on where other governments stood. In the fifth in a series about the legacy of September 11, Dewey Sim and Danny Lee explore how the event changed aviation and look at the threats the sector continues to face.

On July 15, 2017, staff at the Etihad Airways check-in counter in Sydney airport declined to put through a large, heavy suitcase belonging to a passenger travelling to the United Arab Emirates.

Their decision was based on security rules that were implemented after the September 11 terror attacks in the United States, which included baggage weight, size and shape limitations, and a higher scrutiny on checked luggage contents.

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Little did they know, their act helped to foil an Islamic State-linked bomb plot.

The bag, carried by Amer Khayat, contained an improvised explosive device hidden inside a meat grinder. He was arrested upon arrival in Lebanon. His brothers in Australia, Khaled and Mahmoud, were later convicted of covertly planting the bomb in Amer's bag with the aim of detonating it mid-flight.

Smoke rises from the World Trade Center in New York, after the September 11 attacks. Photo: EPA-EFE alt=Smoke rises from the World Trade Center in New York, after the September 11 attacks. Photo: EPA-EFE

About five months before, the US and British governments had banned travellers from certain cities in the Middle East and North Africa from carrying a variety of electronic devices over fears explosives could be concealed and brought onto an aircraft.

The near miss in Sydney and the ban on electronic devices are examples of how the aviation industry has raised its vigilance in a global effort to thwart terrorism after the events of September 11, in which four planes were hijacked and turned into weapons, killing 246 passengers and 2,731 people on the ground in the worst attack on American soil.

The resulting horror and outrage prompted Washington to launch a war on terror that began with the invasion of Afghanistan in October 2001, culminating just last month in a chaotic troop withdrawal and the fall of Kabul to the Taliban.

Subhas Menon, chief executive of Singapore Airlines' regional subsidiary SilkAir from 2001 to 2004, said September 11 "damaged the whole psychology of air travel".

"The whole aviation industry was completely shocked. An aircraft being used as a terrorist weapon against their own people - it was just unthinkable before September 11," said Menon, now director general of the Association of Asia Pacific Airlines.

The attack triggered a wave of new security measures that travellers initially found tedious but have become accustomed to today. While travel fears grew in the wake of September 11, the sector recovered to reach a total of 1.4 billion international tourist arrivals in 2018.

But terror threats remain, with coronavirus-era measures leading to yet more rules that will again change the face of aviation safety, perhaps even for the better, says one analyst.

US travellers go though a security checkpoint in the main terminal of Denver International Airport. Photo: AP alt=US travellers go though a security checkpoint in the main terminal of Denver International Airport. Photo: AP

Faizal Abdul Rahman, a research fellow at the S. Rajaratnam School of International Studies (RSIS) in Singapore, said September 11 "shocked the world into realising that aviation security was lacking against unconventional threats".

There had been previous high-profile international terrorism incidents that involved plane hijackings and vehicle-borne improvised explosive devices, but September 11 "marked an innovation of tactics and strategy that evaded the then-existing aviation security measures", he said.

Governments around the world moved swiftly to improve their intelligence systems and came up with response plans in the event of terrorists weaponising another commercial jetliner.

One of the security changes included the drawing up of restricted areas, such as boarding gates, that only allowed access to ticketed passengers, said Oren Tatcher, an airport planner who has worked on projects in places including Hong Kong and Singapore.

Governments also quickly shored up cockpit defences - a long-standing weak point exposed by hijackers.

Menon, the former executive at Silkair - which has since 2018 merged with its parent Singapore Airlines - said the airline at the time took steps to bolster the cockpit door in a move that was also adopted elsewhere.

Air marshals became regularly stationed on board certain flights out of Singapore, and especially throughout the US, Menon added.

Air marshals became commonplace on flights after September 11. Photo: EPA-EFE alt=Air marshals became commonplace on flights after September 11. Photo: EPA-EFE

Faizal from RSIS said governments also improved pre-screening procedures with higher-tech equipment to detect weapons and explosives, and shared intelligence of travellers with officials.

Singapore's Changi Airport stepped up screening of passengers and their baggage in the immediate aftermath of the September 11 attacks, with greater focus placed on additional physical searches, said Alan Tan, senior vice president of aviation security at Changi Airport Group.

Similarly, in Hong Kong, authorities monitored baggage and hand luggage more closely, in particular those bound for the US, said Albert Lam Kwong-yu, the civil aviation chief from 1998 to 2004.

Days after September 11, his officials plugged a glaring loophole that allowed small knives to pass through Hong Kong airport security.

Tony Tyler, a senior executive at Cathay Pacific at the time who later in the decade became its CEO, recalled the airline had X-rayed bags years before it became compulsory to do so.

"Security and safety management is always a matter of risk management, and I think the measures and approaches taken pre-September 11 in Asia and elsewhere seemed sensible enough," said Tyler, who was the head of International Air Transport Association (IATA) from 2011 to 2016.

"September 11 proved to the industry that it was essential to stay ahead of threats," he said. "It has the resources and intellectual firepower to do so."

For Changi Airport, the attacks prompted further changes. It revealed that perpetrators had conducted pre-attack intelligence gathering and had even observed and tested airport security protocols.

Noting this, the airport introduced a behavioural-based detection programme, under which frontline airport staff were trained to identify suspicious behaviour during their interactions with passengers. This scheme has since been expanded to include more staff such as cleaners and retail workers, the firm said.

Over the years, Changi Airport also improved its passenger identity verification processes and upgraded its airport perimeter fence with an intrusion detection system.

Briton Richard Reid tried to blow up a flight with bombs in his shoes. File photo: Reuters alt=Briton Richard Reid tried to blow up a flight with bombs in his shoes. File photo: Reuters

More substantive changes to aviation security rules came after "shoe-bomber" Richard Reid in December 2001 failed a bid to blow up an American Airlines flight in Paris bound for Miami, and terror plots to discharge liquid explosives across the transatlantic ocean were foiled in 2006.

New rules saw passengers having to remove their shoes for checks and restricted from carrying liquid containers larger than 100 millilitres (0.2 pints) onto aircraft.

Tatcher, the airport planner, said the additional checks challenged limited airport spaces and had an impact on how airports were designed.

Notably, the screening of checked-in luggage became mandatory. "That was a big deal because these machines are enormous," he said.

Passengers check in at Cathay Pacific counters at the Hong Kong International Airport. Photo: K.Y. Cheng alt=Passengers check in at Cathay Pacific counters at the Hong Kong International Airport. Photo: K.Y. Cheng

While newer airports, such as Hong Kong's, had such technology in place, it was "almost impossible" to fit the machines in older airports. Some airports reconstructed or expanded their older terminals to comply with the new rule.

That way, the September 11 attacks served as a catalyst for innovation and investment in research and development, said Tatcher. Equipment is constantly upgraded and there is growing interest in making security checks smoother.

Jim Cherry, a strategic aviation adviser at British engineering consultancy firm Arup, said the updated airport security protocols changed passenger behaviour, as they now had to arrive several hours before their flights.

"Because the security process was more thorough and often entailed waiting in long lines, passengers were no longer interested in any distractions and proceeded as quickly as possible to and through the search points," he said.

Yet, once they have cleared the screening processes, passengers often find themselves with hours of free time.

"The consequence of the dramatic increase in dwell time and significantly larger number of people in the secured zone led to major changes in space allocation, restaurant and boutique placement and other accommodation," Cherry said.

Many airports suspended major expansion and modernisation plans to reconsider how space would have to be reconfigured to reflect the demands of this new reality, he added.

Rescue workers at the site of the World Trade Center terror attack in New York. File photo: EPA-EFE alt=Rescue workers at the site of the World Trade Center terror attack in New York. File photo: EPA-EFE

Twenty years of tightened security measures later, the chances of authorities detecting terror plots have vastly improved "through profiling, for possessing weapons and explosive materials, or for using stolen and fake travel documents", said Faizal, the RSIS academic and head of the institute's Centre of Excellence for National Security.

"Moreover, counterterrorism efforts on land help to ensure that terrorists cannot bring their schemes to the air," he added.

But Faizal said that loopholes remained, as there were varying levels of security in different countries. For example, there had been instances of passengers using stolen passports, while terrorists may also deploy "clean skins" - persons with no records of criminal or extremist behaviour - to evade detection, he said.

Clement Lai Ka-chi, who helped to form Hong Kong's Counter Terrorism Response Unit and was in charge of the city's airport policing and security team from 2006 to 2009, said highly motivated perpetrators would always find weaknesses in the rules.

"Evil people are always evil. They have some strong beliefs and will carry on with that. Lone wolves are especially hard to prove since their existence without any organisation means that they will find a way to prove themselves, and be ahead of the game."

A dog handler checks luggage off a Ryanair flight in Minsk. File photo: AFP alt=A dog handler checks luggage off a Ryanair flight in Minsk. File photo: AFP

Matthew Vaughan, director of aviation security and cyber at IATA, said global aviation rules had since 2001 been revised eight times, to "make sure the security settings are just relevant in the areas we need to protect".

"Twenty years on, we live under a rules-based approach today and it ultimately has to keep changing," he said.

Vaughan, who was security chief at Etihad before the plot emerged, said a terrorist's aim to exploit system vulnerabilities would never go away, but "we can certainly do something about influencing the particular pathways or options they think are available to exploit".

He pointed out that September 11 was a domestic terror event, and even with stringent international rules for aviation, it was up to governments to ensure high standards of safety.

With analysts warning that extremist groups will be emboldened by the Taliban seizing power in Afghanistan, the threat of terrorism remains very much alive.

Terrorists are constantly looking for opportunities to launch attacks that cause high damage and fear, so it is crucial for airports to remain alert even during periods where the threat is perceived to be low, Faizal said.

An airport security worker patrols in protective gear at Shanghai Pudong International Airport. Photo: AFP alt=An airport security worker patrols in protective gear at Shanghai Pudong International Airport. Photo: AFP

"We need to watch for new threats if the Taliban's return to power enables al-Qaeda to revive its international agenda over the next decade," he said.

Airports should cooperate with security agencies to share intelligence while anticipating how changes in travel patterns and technology could enable new attacks, Faizal added.

Following Kabul's fall to the Taliban, former British prime minister Tony Blair also warned about the need to protect people against bioterrorism threats, such as the release of viruses.

"Its defeat will come ultimately through confronting both the violence and the ideology, by a combination of hard and soft power," he said.

Faizal said governments had been monitoring bioterrorism activity from as early as the 1990s, after Japanese cult group and terrorist organisation Aum Shinrikyo in 1995 launched a sarin gas attack in the Tokyo subway, which injured thousands.

Japanese authorities last year said Aum Shinrikyo remained a threat, with three splinter groups actively recruiting members and building up cash reserves.

Passengers queue up to check in at Sydney Airport. Photo: AP alt=Passengers queue up to check in at Sydney Airport. Photo: AP

Meanwhile, the latest threat to aviation is Covid-19, which has disrupted global travel and left airlines and airports operating at a fraction of their peak. Many countries have implemented measures including on-arrival tests and quarantine zones at airports.

Cherry, the aviation adviser from Arup, pointed out that technologies such as remote and touch-free check-ins as well as self-baggage check-ins, were already being used at some airports even before the pandemic.

"Clearly, the onset of the pandemic has served to accelerate that implementation and will most certainly lead to new, creative ways to further reduce the risk of spreading contagion," he said.

Faizal said that pandemic measures served as an additional layer of vetting and monitoring that would make air travel more difficult and costly for international terrorists.

After September 11, the increased aviation security measures brought inconvenience but travellers eventually accepted them as the new normal for safe air travel, he said.

"Looking ahead, travellers would also have to accept the inconveniences of pandemic-era air travel, especially if flying is now more for necessity, not luxury."

This article originally appeared on the South China Morning Post (SCMP).

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