Tim Van Beveren is a pilot and television journalist, and has published several books on aviation security.

DW-WORLD.DE: Have airplane hijackings increased or decreased since the Sept. 11 terrorist attacks in the US?

Tim Van Beveren: One cannot really speak of a tendency. There have been some airplane hijackings since then. More important, however, is the way hijackings have changed. In the past, one usually assumed that passengers would be held hostage and let go if certain demands were met. On Sept. 11, 2001, planes were used as bombs, and exchanging passengers was not the issue at all. That kind of scenario is a huge problem for security experts.

One can then say that plane hijackings have reached a new dimension since the Sept. 11 attacks?

The potential for attacks has changed completely. If a plane is hijacked, aviation security experts must at least assume that there might be a repeat of the 9/11 attacks. That is why a debate has begun about whether such hijacked planes should be shot down. The most recent example was the plane just last month -- in August -- which two people hijacked en route from Cyprus to Turkey. The two were only using mock bombs, and the hijacking did not turn bloody; nonetheless, the two hijackers were still able to take control of the plane through violent means.

Are pilots now better trained to deal with these situations?

With the plane that was on its way to Turkey, the pilot ended up fleeing the cockpit as soon as the plane landed. That was certainly a clever move, since it meant no one was there anymore who was actually capable of flying the plane. But now a legal case is being made against him for precisely that reason, and he must fear losing his pilot's license. Following the Sept. 11 attacks, pilots were certainly trained to handle the situation differently. Before, the method was to fulfill the terrorists' demands, to remain calm and to prevent the situation from escalating. Since 9/11, pilots are required to land the plane as soon as possible and alert the authorities, which could mean that the plane would ultimately be shot down if a landing hasn't occurred already.

How has technology changed in this regard?

Nowadays, the doors to cockpits are reinforced. Cockpits are more like bank vaults now. Pilots are also forbidden to open up the door, even if passengers or crew are being threatened. Instead, they are supposed to land the plane immediately. That is certainly a step in the right direction. Other things have changed as well -- technology that can detect bombs and weapons has been improved. But there is no guarantee that hijackers will necessarily choose a particular method for a hijacking, or that they will bring the materials they need on board themselves. There have also been cases in which airline or airport staff in security-relevant areas have connections to terrorist networks. For instance, it is relatively easy for cleaning personnel or mechanics to place necessary materials on board a plane. These so-called sleeper agents who have been working for an airport or airline for a long time are the greatest danger.

How should passengers behave should a hijacking occur or some other terrorist threat emerge?

That is also a double-edged sword. On the one hand, the only way to try to escape such a dangerous situation is to do what the passengers on board the fourth plane [the plane that crashed in Pennsylvania] did on Sept. 11. They stormed the cockpit and tried to overtake the hijackers. A great deal of courage is required for such behavior, and also, the ability to assess the situation correctly. On the other hand, one can hardly imagine what would happen if a passenger started acting strangely, say, if he or she was suffering from claustrophobia and the other passengers on board suddenly attacked him or her due to the strange behavior. That has actually happened before -- a passenger was pushed to the ground on a plane and was choked to death in the process.

Is the threat of hijackings such as those on Sept. 11, 2001 still imminent?

I think the threat is always there and terrorism is a phenomenon we must address now more than ever. There is no universal remedy for the situation, no 100-percent guarantee of safety. Just as security experts try to conceive new means of preventing hijackings, terrorists too are developing ways of getting around those methods, and concocting plans for new attacks that would grab even greater attention. The risk is still there.

Elisabeth Otto interviewed Tim Van Beveren (als)