The Homeland Security Department and the FBI issued a memo last month warning that terrorists have explored using lasers as weapons. Transportation Secretary Norman Mineta said earlier this month that there have been 31 incidents since the end of December in which laser beams were shone into airplane cockpits during flight.
"A recent rash of incidents involving lasers aimed at aircraft cockpits has raised concerns over the potential threat to aviation safety and security," according to a Congressional Research Service report, which was published this week by the Federation of American Scientists' Project on Government Secrecy. "While none of these incidents has been linked to terrorism, security officials have expressed concern that terrorists may seek to acquire and use higher powered lasers to, among other things, incapacitate pilots."
Lasers, an acronym for light amplification by stimulated emission of radiation, come in different forms and strengths, ranging from low-powered handheld ones to forceful industrial systems. Some lasers that can cause eye damage through momentary exposure are packaged as laser pointers and can be purchased over the Internet, the report says.
"While most would agree that incapacitating both pilots and downing an airliner by aiming a handheld laser pointer into the cockpit is highly unlikely, there is concern that a military laser, such as the Chinese-made ZM-87 laser blinder, or a high powered industrial laser in the hands of terrorists could pose a more significant threat," the report adds. "There is also concern that terrorists may improvise an intense laser blinder by bundling several higher powered handheld laser devices."
The report says policymakers might want to consider a range of options to mitigate the threat of lasers, such as restricting the sale or use of certain laser devices; amending criminal statutes associated with interfering with flight operations; providing pilots with laser eye protection; expanding and enforcing laser-free zones around airports; and educating the public regarding the risks of lasers to aviation safety.
According to the FAA, there have been more than 400 incidents since 1990 in which pilots have been startled, distracted, temporarily blinded or disoriented by laser exposure. To date, however, no aviation accidents have been attributed to laser lights.
The FAA noted that a "laser attack could be quickly deployed and withdrawn, leaving no obvious collateral damage or projectile residue, and would be difficult to detect and defend against."
The report says that although no official conclusions have been reached, the recent rash of laser incidents may be attributable to the increasing availability and reduced cost of green laser pointers, which are about 35 times brighter than red lasers.
The report notes, however, the difficulty in protecting airliners from laser incidents. "Pre-empting a terrorist attack using lasers would likely be extremely difficult because a laser would be virtually undetectable until shined at an aircraft, and even then, may be difficult to spot from the ground."