Air Transportation Security
or Insecurity

The incidents of September 11 triggered major changes in air transportation security procedures. Most of the changes appear to be only cosmetic. Few changes are functional in reducing the potential for terrorist attacks. A functional procedure substantially reduces the opportunity for a terrorist attack or contains the damage that terrorist can inflict; a cosmetic procedure is visible to travelers and may improve confidence but contain security defects that can be exploited by a planned and coordinated terrorist operation.

In any security discussion, one point must be constantly kept in mind: Absolute security is an illusion. A determined opponent willing to spend time and resources can compromise any procedure. The objectives are to make the attack very difficult and to contain the damage that can result from an attack.

A terrorist can attempt any of three types of attacks on air transportation: use airplanes as weapons to attack other targets, attack an airplane and passengers, and attack the terminals or ground facilities.


To use an airplane as a weapon, a terrorist must gain control of the cockpit. If the terrorist is a passenger, this attack can be prevented by sealing the cabin from the cockpit so that it cannot be penetrated without destroying the plane. The cockpit should be sealed any time passengers are on the plane. Two other approaches to gain control of the cockpit should be considered; ground a maintenance personnel and cockpit crew ("rogue pilot"). Attack by ground personnel can be prevented by failsafe mechanisms that prevent flight unless an authorized pilot is in the cockpit. Preventing a rogue pilot from gaining control is more difficult and may be impossible. A terrorist organization with a five year planning horizon could introduce pilots into the air transportation system or compromise a pilot to the point that cooperation with terrorists may appear to be the best option. Intensive and frequent background investigations should detect most potential rogue pilots. Remotely controlled destruct mechanisms or interceptor planes may be necessary for those that evade the background checks.


Attack in flight may be by armed terrorists in the cabin, explosives concealed in luggage or parcels, or by surface-to-air missiles. Intensive security procedures should detect most weapons carried on board, however, weapons could be developed to avoid security procedures. Weapons could be concealed under seats, in restrooms, or other areas by ground service personnel. Weapons could also be in the luggage of flight attendants. A terrorist would pass gate security without suspicion and retrieve these weapons. All personnel with access to the plane, including flight crew and ground service personnel, should be subject to full security procedures. Randomizing the work assignments of ground service personnel would inhibit cooperation with terrorists. An individual would not be able to anticipate access to particular planes which would interrupt planning between service personnel and on board terrorists. Armed security personnel could observe cabin servicing. Detecting explosives concealed in luggage or parcels require inspection of each item. A substantial portion of the inspection can probably be automated, but manual inspection of suspicious items and random selection from all items would improve effectiveness. Ensuring that the individual checking luggage is on the plane is of little benefit against terrorists willing to accept suicide. The capability to flood the cabin with sleep gas could minimize damage. An attack using surface to air missiles is most likely during take off or landing. Extending the physical security zone to the higher risk areas could be implemented in some cases. Development of a missile defense system is possible.


Attacks against the terminal may be through car bombs, terrorists armed with bombs or guns, or airport service vehicles such as aviation fuel trucks. The threat from car bombs can be mitigated by barricades that prevent vehicles from closely approaching the terminal. Bombs in luggage can possibly be detected with sensors at the terminal entrances. Armed security forces that patrol the terminal areas could suppress terrorist gun attacks. Mini satellite terminals could provide security screening outside the main terminal. Passengers and inspected luggage would then be transported in secure busses to the main terminal. The small capacities of the satellite terminals would limit the potential damage. An aviation fuel truck could be used as a major bomb with only a small trigger explosive. The potential for damage could be contained by refueling planes at locations remote from the terminal. Refueling would be done without passengers on the plane.


Any regular scheduled personnel assignment can be exploited by terrorist organizations. Randomizing personnel assignments would minimize the possibility of exploitation. To maximize randomization, a common organization should control all security and ground service personnel. The airlines would only manage reservations, sell tickets, and fly planes. Other airport personnel, except military, would be controlled by the airport authority or the Department of Transportation. Department of Defense personnel would be most effectively used as roving patrols of the entire airport area. Unchallenged procedures soon become ineffective. Frequent penetration attempts by an independent organization (possibly the Department of Justice) would help maintain security procedures at peak effectiveness.


The flight data and cockpit voice recorders are essentially 1970s implementations of 1950s concepts. Improved on board recorders can be implemented with current technology but the primary recording should be done on the ground. Continuous communications would relay the data to ground sites. Automated voice characteristics and speech recognition could alert security personnel of potential terrorist activities and other dangerous conditions. Cabin voice recorders could also be implemented with a threshold, such as a scream or gunshot, to activate recording.


Pre-clearance of trusted passengers could improve processing time but would not reduce threats unless a comprehensive bio-metric identification system is developed. Any system based on ID cards can be compromised. Arming pilots would probably not be effective. Would it be better to arm passengers? Possibly if non-lethal weapons are used.



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