Measure For Measure: Air Travel and Terrorists

Anyone who has traveled by air recently will have experienced the new security directives banning liquids, jells and pastes from being taken onboard an aircraft. These new security regulations came about following the plot to blow up multiple flights over the Atlantic from the UK to the US. This article will examine the issue and assess the effectiveness of the new measures being taken by the T.S.A. in preventing terror plots involving possible binary liquid explosives and others.

To begin with, liquid explosives are nothing new in the terrorist tackle bag. In 1987 a bottle of liquid explosive in a carry-on bag brought down a South Korean airliner, killing 115 people on board. In 1994, al Qaeda terrorist, Ramzi Yousef, used liquid nitroglycerine hidden in contact-lens cleaner bottles to blast a Philippine Airliner, killing one passenger and injuring several others. Apparently, that was a trial run for a plan to blowup as many as 12 US-bound passenger planes over the Pacific. Yet again, al Qaeda duplicates its previous successful actions, this time trying to bring down 10 US-bound airliners, this time over the Atlantic.

Liquid explosives are quite numerous but very few of them would be of any use to a terrorist set on blowing up a plane. Terrorists' default explosives today would be Triacerone triperoxide (TATP) and nitroglycerine because the components used to make them are readily available and are easy to handle. The danger occurs when the precursors are mixed together, they then become quite unstable and "shock sensitive". TATP can be liquefied using concentrated ether, but then has to be highly concentrated, the resulting fluid is very unstable and sensitive and could detonate by just a sudden movement, making it all too risky to ever be used on board an aircraft. Both explosives need time to make and require a good deal of delicacy during the operations; TATP being notoriously unstable, has to be prepared at a low temperature and then completely dried into a crystalline powder before it can be successfully exploited. Consequently, there is very little likelihood that a terrorist could ever assemble such compounds unnoticed on a plane, or would even attempt to.

Other possible explosive materials have a tendency to effervesce and give off fumes once mixed together that would expose the scheme. The only one that might have some advantage to a would-be bomber, that requires two liquids, is an explosive that is used in quarries containing concentrated nitric acid and hydrazine. The challenge for the terrorist is that while it is only available in the US and is strictly controlled, the ingredients are relatively easy to acquire. So, why all the fuss over liquids and why are crystalline powders not forbidden? The answer could be, whereas nitroglycerine can be detected by screening technology, it cannot pick up TATP, and the binary liquid explosive so feared today could be the American one mentioned above that somehow has come into the hands of terrorists.

A caveat worth reiterating is that technology is not the whole answer and dependency on it can be as dangerous as the terrorist's intentions. Nothing beats well-trained human observers examining the behavior of passengers; proof of that lies in the safety record of Israeli airliners.
Anyone who has traveled by air recently will have experienced the new security directives banning liquids, jells and pastes from being taken onboard an aircraft. These new security regulations came about following the plot to blow up multiple flights over the Atlantic from the UK to the US. This article will examine the issue and assess the effectiveness of the new measures being taken by the T.S.A. in preventing terror plots involving possible binary liquid explosives and others.

To begin with, liquid explosives are nothing new in the terrorist tackle bag. In 1987 a bottle of liquid explosive in a carry-on bag brought down a South Korean airliner, killing 115 people on board. In 1994, al Qaeda terrorist, Ramzi Yousef, used liquid nitroglycerine hidden in contact-lens cleaner bottles to blast a Philippine Airliner, killing one passenger and injuring several others. Apparently, that was a trial run for a plan to blowup as many as 12 US-bound passenger planes over the Pacific. Yet again, al Qaeda duplicates its previous successful actions, this time trying to bring down 10 US-bound airliners, this time over the Atlantic.

Liquid explosives are quite numerous but very few of them would be of any use to a terrorist set on blowing up a plane. Terrorists' default explosives today would be Triacerone triperoxide (TATP) and nitroglycerine because the components used to make them are readily available and are easy to handle. The danger occurs when the precursors are mixed together, they then become quite unstable and "shock sensitive". TATP can be liquefied using concentrated ether, but then has to be highly concentrated, the resulting fluid is very unstable and sensitive and could detonate by just a sudden movement, making it all too risky to ever be used on board an aircraft. Both explosives need time to make and require a good deal of delicacy during the operations; TATP being notoriously unstable, has to be prepared at a low temperature and then completely dried into a crystalline powder before it can be successfully exploited. Consequently, there is very little likelihood that a terrorist could ever assemble such compounds unnoticed on a plane, or would even attempt to.

Other possible explosive materials have a tendency to effervesce and give off fumes once mixed together that would expose the scheme. The only one that might have some advantage to a would-be bomber, that requires two liquids, is an explosive that is used in quarries containing concentrated nitric acid and hydrazine. The challenge for the terrorist is that while it is only available in the US and is strictly controlled, the ingredients are relatively easy to acquire. So, why all the fuss over liquids and why are crystalline powders not forbidden? The answer could be, whereas nitroglycerine can be detected by screening technology, it cannot pick up TATP, and the binary liquid explosive so feared today could be the American one mentioned above that somehow has come into the hands of terrorists.

A caveat worth reiterating is that technology is not the whole answer and dependency on it can be as dangerous as the terrorist's intentions. Nothing beats well-trained human observers examining the behavior of passengers; proof of that lies in the safety record of Israeli airliners.