Civil Aviation and Terrorism: Challenges and Responses

The attack on Istanbul’s Ataturk airport on 28 June was the latest incident over the last year to highlight the terrorist threat to civil aviation. Many have drawn parallels with the downing of Metrojet 9268 over Egypt’s Sinai Peninsula in October and the attack on Zaventem airport in March. Although all of these incidents were attributed to Islamic State (IS) the different methods of attack used underscores the range of options available to those intent on targeting the aviation industry.

The requirement to prevent such attacks in the future will place a growing premium on security cooperation between the public and private sector, particularly in light of the range of options available to those intent on targeting aviation interests and the expected growth in passenger numbers. Incidents over the last year also serve as a reminder of the principle of proportionality; whatever the extent of security cooperation or the countermeasures adopted, nothing is capable of delivering perfect protection.

Subverting Screening Measures

Innovation amongst terrorist groups has proven a major security challenge. The 2001 shoe bomb plot, 2006 liquid bomb plot, 2009 underwear bomb plot, and 2010 printer cartridge bomb plot show Al-Qaeda’s (AQ) capability and intent to overcome screening measures by designing novel improvised explosive devices (IEDs). AQ’s Yemeni affiliate, Al Qaeda in the Arabian Peninsula (AQAP), retains a reputation for having the most highly skilled bomb makers of any terrorist group. While Saudi national Ibrahim al-Asiri is perhaps the best known of these, the group boasted in 2010 there were many others like him. The December 2014 edition of AQAP’s Inspire magazine provided instructions on how to construct IEDs, which the authors claimed were capable of subverting airport screening. This suggests the group remains committed to this modus operandi despite a lack of previous success.

Bomb-sniffing dog at the Detroit airport. (Photo by Bill Pugliano)

IS’s attack on Metrojet 9268 in Egypt in October demonstrated screening measures could be subverted by human rather than technical innovation. The device the group claimed brought down the plane appears simple compared to those designed by AQAP: a can filled with TNT placed on board by an airport worker. While imaging devices and the use of explosive detection dogs may prevent, or at least deter, attempts by passengers to smuggle such devices on board flights, they offer little protection from employees not required to pass through airport screening. AQ’s Somali affiliate, al-Shabaab, blended aspects of both these approaches in its attack on Daallo Airlines 159. In this instance, a sophisticated IED concealed in a laptop was smuggled through screening by airport employees before being handed to a passenger to detonate mid-flight. Continued attempts to subvert screening measures by blending technical and human innovation will pose a long-term challenge to aviation security. Given AQ’s history of abandoning new methods and devices immediately after they’ve failed, purely reactive security measures are less likely to be effective against such a challenge.

Direct Assault

As in previous cases in Glasgow, Karachi and Brussels, the July attack on Istanbul airport is an example of terrorists using overwhelming force rather than technical innovation or an insider. In these instances the use of vehicles, IEDs and automatic weapons allowed passengers to be targeted whilst awaiting screening. On 29 June, the Chairman of the IATA, an airline trade association, suggested moving passengers more rapidly through this process may reduce their vulnerability from this type of attack. However, given the expected growth in passenger numbers over the next 20 years, faster screening procedures will only go so far in changing terrorist perceptions of airports as crowded, target-rich environments. Faster screening measures are also unlikely to change perceptions of attacks on civil aviation, even if unsuccessful, as capable of having a disproportionately disruptive economic and psychological impact on target nations when compared to other potential targets.

As these types of attack take place prior to screening, and in close proximity to their intended targets, options for timely prevention are limited. One possible solution is to extend security perimeters to less crowded areas further away from terminals. This may include screening vehicles prior to their arrival at drop-off zones, a task more easily achievable in airports located outside of city centres, such as facilities in Bangkok, Kuala Lumpur and Tel Aviv. However, concerns over traffic congestion make these measures impractical for airports in more built up areas. Another potential fix is to capitalise on the fact that direct assaults require a degree of pre-planning, typically including reconnaissance of the target. While screening for suspicious behaviours rather than restricted items may therefore prove more effective at detection, such methods have previously been accused of inefficiency and subject to civil liberties-related litigation and links to racial profiling. All of these factors may prevent more widespread adoption.

Attack From Outside Airport Perimeters

A mortar round exploded near his parked Boeing 737-800 during an attack on Istanbul’s Sabiha Gokcen airport. (DHA Photo)

Terrorist groups unable or unwilling to subvert screening measures, manipulate an insider, or mount a direct assault on a terminal have previously launched attacks from outside of airport perimeters. On 4 July a camp for Iranian dissidents adjacent to Baghdad’s international airport was hit by mortar fire for the second time since October. Istanbul’s Sabiha Gokcen airport was similarly targeted in December. Extending perimeter fencing as a countermeasure is impractical for airports in built-up areas. The array of weapons capable of firing considerable distances means such extensions may not necessarily solve this problem for those facilities with the room to expand.

...between 1975 and 2011, 40 civilian aircraft, predominantly helicopters and propeller driven aircraft, were successfully hit using MANPADS...

Of these weapons, groups have previously shown a preference for man-portable surface-to-air missile system (MANPADS). The US State Department suggests that between 1975 and 2011, 40 civilian aircraft, predominantly helicopters and propeller driven aircraft, were successfully hit using MANPADS. These attacks caused 28 crashes and over 800 deaths. Since this data was collected, the looting of weapons stockpiles in Syria and Libya have contributed to the proliferation of small arms capable of targeting aviation interests. Whilst MANPADS are incapable of reaching the cruising altitude of commercial aircraft, and most carriers avoid transiting Syrian and Libyan airspace, such proliferation enables threat migration, as in  2002 when terrorists used MANPADS to target a commercial airliner during take-off in Kenya. Although not directed at aviation interests, a more recent plot to target Singapore’s Marina Bay using GRAD rockets fired from a nearby Indonesian island underscores the issue of perimeter security. The ability to prevent these attacks rests heavily with law enforcement and arms control measures.


Vulnerabilities exist in any security system including those at airports. X-ray scanners, or those monitoring them, can fail to spot prohibited items, employee background checks can miss red flags, and perimeter fencing can be breached. As former US Transportation Security Administration head Kip Hawley has suggested, the key is to layer these measures; if one is breached, others pick up the slack. The requirement to protect a growing number of passengers from terrorists adopting a variety of methods will test the capacity of these ‘layers’ over the next 20 years. These pressures require a more targeted approach to aviation security, underpinned by closer cooperation between the security services and airport security personnel. Airports remain commercial entities, not counterterrorism organisations. If government officials demand airport security be convenient as well as safe, government agencies have a central role to play.

Given the myriad of options available to terrorists, further attacks are likely whatever measures are employed.

Truly preventive measures will of course remain the exclusive remit of state agencies, lowering the threat by arresting assailants before they reach their targets. However, designing airport security procedures based on relevant, current intelligence would help stem criticism of their being ‘theatre’ based on outdated scenarios. Obstacles to this approach include government hesitancy to share sensitive information with organisations accused of inadequate employee screening procedures. These risks must be balanced against the high likelihood terrorists will look to target increasingly busy airports in future, and the social and economic disruption caused by inefficient screening and security-related delays.

A sense of proportionality is also important. Despite attacks in Brussels occurring on both the metro system and the airport, commentary tends to disproportionately focus on the latter. Such blanket media coverage can skew perceptions of the threat, particularly at airports, where this plays into general, if irrational, fears of flying. A more balanced focus would give greater weight to the fact attacks have also taken place at train stations, holiday resorts, cafes, concerts, hotels and sporting events, sites at which screening remains minimal by comparison. Given the myriad of options available to terrorists, further attacks are likely whatever measures are employed. The focus on preventing attacks should therefore be balanced with an ability to respond and recover when they do. As terrorists aim to use violence, in part, to disrupt national economies, the ability of officials to reopen airports quickly following an attack may go some way to countering this aim, deterring similar attacks and protecting broader national interests.

John Still is an intelligence analyst for a large corporate organisation. He is focused on security and political issues, including terrorism, civil unrest and organised crime in Europe, the Middle East and Africa. His research interests include organisational learning, with a specific focus on isomorphism and hierarchy. The views and opinions expressed by the author herein do not necessarily reflect those of his employer or any of its subsidiaries.

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Header Image: A Turkish riot police officer patrols Ataturk Airport’s main entrance in Istanbul on June 28, 2016. (Ozan Kose/AFP/Getty Images)