Militants probe aviation security weak points

LONDON (Reuters) - An attempted attack on a U.S. plane on Christmas Day illustrates aviation's enduring need for vigilance against determined extremists constantly trying to outwit the industry's defenses to inflict devastating harm.

So strong is the sector's lure as a target for militants that the security industry must innovate ceaselessly to stay one step ahead, and even then total protection for air travelers is no more achievable than it is in any other branch of transport.

"It's a contest," said Henry Wilkinson of Janusian Security in London, noting militants make a point of researching to identify and exploit weaknesses in aviation security.

"It's highly like that when security improvements devised as a result of this latest incident have been put in place, terrorists will come up with a way to get round them."

In the Christmas Day incident, a Nigerian man believed to be linked to al Qaeda militants was in custody on Saturday after he tried to ignite an explosive device on a U.S. passenger plane as it approached Detroit, U.S. officials said.

The suspect, who suffered extensive burns, was overpowered by passengers and crew on the flight from Amsterdam. The passengers, two of whom suffered minor injuries, disembarked safely from the Delta Air Lines plane.

DANGEROUS MATERIALS

Security experts say that while the industry's defenses have improved in recent years, there is no widely deployed technology to routinely guard against a bomber with explosives hidden in a body cavity or strapped to his body.

Dutch counter-terrorism agency NCTb said in a statement the man went through security at Schiphol airport but added it could not rule out the potential for dangerous items to be brought on board, "especially objects that with the current security technology such as metal detectors are difficult to detect."

Security experts said it was important to establish how the man took the device aboard and how much was known about him by counter-terrorism officials tasked with monitoring potentially dangerous individuals.

"This case is an example of how groups and/or individuals wanting to make a point continue to probe the aviation industry for weaknesses," said Chris Yates of Jane's Aviation.

Yates and other experts noted that if passengers do not set off an alarm during pre-board electronic screening there is less chance they will be "patted down" by security staff -- a simple but reasonably effective search if performed correctly.

"We need to establish exactly what happened. But this incident does appear to be very worrying: No one should be able to get dangerous materials onto a plane," he said.

Militants have a powerful rationale for putting aviation high on their list of favorite targets and deploying the maximum ingenuity to ensure success.

Simply by choosing to bomb a commercial airliner, an attacker is guaranteed wide publicity. If the target is also on an international route the effect is multiplied, with the news and its attendant terror effect spreading across the globe.

LIQUID EXPLOSIVES PLOT

And if the plane's destination is the United States, the attack, if successful, is sure to harm Americans, a top goal for anti-Western militants such as those of Osama bin Laden's al Qaeda and its loose network of like-minded allied groups.

Security analyst Paul Beaver said Friday's incident showed airliners remained an iconic target with a particularly Western character because of the Western origins of commercial aviation.

"Very few ships have been attacked in comparison. With ships, it's more difficult to get the same publicity effect," he said.

Justin Crump, Head of Terrorism and Country Risk at Stirling Assynt security consultancy, said the September 11, 2001 attacks in which planes were commandeered by suicide attackers was the most spectacular example of militants' obsession with aviation.

"Aviation is Western, a symbol of global commerce, a symbol of global communications, and a successful attack is very disruptive, making life harder for everyone through the necessary additional security," he said.

A notable example of militant innovation was a plot by three Britons jailed for life in September for planning to blow up transatlantic airliners bound for North America in mid-flight suicide attacks using bombs made from liquid explosives in 2006.

The bombers intended to simultaneously destroy at least seven planes carrying over 200 passengers each between London's Heathrow airport and the United States and Canada in August 2006 using explosives hidden in soft drink bottles.

The suspected al Qaeda plot, just days from being put into operation according to British detectives, had huge worldwide effects, leading to tight restrictions on the amount of liquids passengers could take on board aircraft.

(Editing by Mark Trevelyan)