My bike commute to work leads me right along the München airport, so it's not difficult to notice that quite a few planes take off in the mornings. Looking at my watch while riding by, it looks like there are about 1 plane a minute taking to the skies. I managed to get off a little earlier this morning and noticed something new. The airport was quiet: no planes were taking off. So, I drove to the observation mound to see what was up. There was some ground traffic -- vehicles scurrying back and forth, but no planes in the air.
Then, one plane took off from the northern airstrip: an El Al flight and banked south, which is unusual as normally southbound planes leave from the southern strip. Very soon after that, about 5 minutes after, planes took off again at the regular pace. I also passed a police car that had been hiding in the bushes along my bike path.
So, I guess what happened was they cleared the airspace for that El-Al flight and probably had all other planes keep their distance on ground, too. They also probably had various police vehicles all over the airport zone checking in to get the tower the all clear, which is why there was nothing happening for such a long time.
What occurred to me after that take off is how much effort goes into creating such a secure flight and how it really doesn't scale well. If you've ever been on an El-Al flight you know what their passenger security procedures look like. On the ground, the flight get a police escort. The pilots are reportedly former military pilots and the planes are equiped with unusual but undisclosed defense systems. Now I realize that just getting that flight into the air (and probably landing it) is also very disruptive. It also makes El-Al probably the safest airline to fly on, but the model is probably overkill for other airlines.
(Picture from http://www.flickr.com/photos/67855182@N00/)