NCPA - National Center for Policy Analysis

Pentagon Considers Ear-Blasting Anti-Hijack Gun

November 19, 2001

The U.S. Department of Defense is assessing new non-lethal weapons technology. Weapons that fire high-intensity "sonic bullets" could be used by sky marshals to incapacitate terrorists who try to hijack passenger aircraft.

A California firm, American Technologies, patented a device that shoots out a pulse of sound that's almost like a bullet. It's capable of producing over 140 decibels for a second or two. Sounds become painful between 120 and 130 decibels.

  • The device could be used on hijackers to inflict pain and possibly disorientation.
  • The main effect is to cause intense pain in the ear drums.
  • Acoustic pulses can also disorient people by shocking the balance system of the inner ear -- an effect known as the Tullio phenomenon.
  • There would be no destruction of fuselage walls and windows.

Non-lethal acoustic weapons have yet to prove themselves in the field, though. Inaudible, low-frequency sound waves -- infrasound - have been claimed to induce nausea and even vomiting. But Jürgen Altmann, an expert in these weapons at the University of Dortmund, says there's no reliable evidence for this.

Altmann says there may be other problems. The beam might hit others, or reflect around the aircraft causing temporary hearing loss in other passengers. Source: Ian Sample, "Pentagon considers ear-blasting anti-hijack gun," News Scientist, November 14, 2001.


Browse more articles on Government Issues