http://www.salon.com/tech/col/smith/2004/12/17/askthepilot116/index.htmlFor the record, even a well-aimed laser would be highly unlikely to cause a crash. Hitting both pilots cleanly in the face, through a refractive wraparound windshield, would require a great deal of luck, and even a temporarily blinded crew would still have the means to avoid disaster. Do not equate the results of a laser strike with, for example, having to drive sightless through a busy intersection. Maintaining a jet's stability would be challenging under the circumstances, but not impossible.
The idea of terrorists bothering with such a plan is tough to accept. Say there's a 10 percent chance of a laser causing an accident. With limited resources and personnel, it's doubtful terrorists are going to risk exposure on an operation with a 90 percent likelihood of failure. (From a technical standpoint, one thing I find interesting is the presumption that approach and landing are the implicitly apropos time for such an attack. In fact, takeoff would be the more dangerous moment.)
The DHS alert states that lasers are "relatively inexpensive, portable, easy to conceal, and readily available on the open market." Yes and no. Powerful military-grade devices are in fact quite expensive and difficult to attain. Cheaper, commercial versions are more widely sold, but also substantially less effective.
Sounds like the shoulder-fired missiles commotion all over again. Or, for that matter, fill in the blank with boxcutters, grenades, machine guns, shoe bombs, and every other variant of alleged terrorist weaponry. When and where does it end? No danger should be ignored, whether the schemings of actual terrorists or the work of teenage vandals with nothing better to do. But to our detriment, we remain pinned in a full and furious default mode, whereby every potential threat becomes, simultaneously, a looming "terrorist weapon" ready to plunge the nation into chaos.