KEN BARAT, LASER SAFETY SOLUTIONS AND JOSH HADLER, NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY
Aircraft illumination by handheld lasers has become a worldwide problem — in the U.S., the FBI offers a $10,000 reward for information leading to a conviction of the crime.
Up in the sky, it’s a bird, it’s a plane! No, it’s a laser beam! And illegal use of them is growing.
The hazard from these lasers is not to the aircraft frame, but to the pilot as a distraction. The distance from which these lasers present a retinal hazard makes it impractical for the operator to be present, while the intensity needed to distract a pilot is extremely low (nanowatt range).
There is a distinction between different types of such devices: a laser pointer is a handheld visible laser device that emits no more than 5 mW as a continuous wave beam. A handheld laser is any laser device that is portable and whose visible output is greater than 5 mW. Today, units from 10 up to 5000 mW are available, which is 5 W in a handheld device.
The effects defined below result from laser pointers and handheld lasers.
Glare is obscuration of an object in a person’s field of vision due to a bright light source near the same line of sight (e.g., oncoming car headlights).
Flash blindness is a visual interference effect that persists after the source of illumination has ceased.
Afterimage is a reverse contrast shadow image left in the visual field after exposure to a bright light that may persist for several minutes.
Risks and testing
National Institute of Standards and Technology researchers have tested 122 laser pointers using a moderately low-cost apparatus designed to quickly and accurately measure the properties of handheld laser devices. They found that nearly 90 percent of green pointers and about 44 percent of red pointers tested were out of compliance with federal safety regulations.
Very little green light is required to illicit detrimental effects at night or in low-light conditions. In 2014, there were 3894 laser incidents reported to the U.S. Federal Aviation Administration (FAA) and 3960 reported in 2013.
The FAA offers a free downloadable video on its website addressing this growing problem; in particular, it explains how pilots should deal with illumination events. This includes helicopter pilots, who fly at considerably lower altitudes, often 1200 feet or closer to the ground.
The danger of illuminating a cockpit is the distraction to the pilot. Imagine you are traveling down the highway in a vehicle at a rapid speed, and now a bright light hits you. While your vision is obscured, you tend to stay straight and maybe slow down until you can see the road again. Now consider a pilot taking off or landing an aircraft; the light hits, and runway lights are blurred. The pilot’s reaction might be to divert the path or turn over to the other pilot, if applicable. It should be noted that changing the flight path could not only endanger the plane but any others in the zone. Diverting the course of a helicopter could present its own problems, such as hitting a nearby power line or building.
The overwhelming majority of handheld lasers are manufactured outside the U.S. Random testing of units has shown questionable quality control, outputs vastly different from indicated and failure to include IR filters for green lasers. The most popular laser unit involved in these events is the green 532-nm laser; it is a great deal of technology in one’s hand. For example, a frequency-doubled Nd:YAG laser system comprises a 808-nm diode pump and Nd:YAG (or Nd:YLF) crystal, generating a 1064-nm beam going through a nonlinear crystal, yielding a bright 532-nm beam and focusing optics. If an IR filter has not been put in place, there is nothing to block the residual 808-nm and 1064-nm beams from exiting.
To the user operating the laser, the beam may seem to end at 1200 feet from its point of origin. The beam that is visible to the user is scattered light from dust and other particles in the air. This layer of dust and aerosols sits close the ground, and once the beam exits that boundary layer, it continues on until it hits something. For example, a 5-mW laser pointer is a distraction hazard to pilots from over two miles away. Some higher output systems can cause serious glare at such distances, while the distraction hazard is 22 miles. The beam will not be consistently on target, but random flashing is commonly reported.
In 2013, there were 74 incidents in which law enforcement action was necessary, and there were 11 prosecutions (including two at the federal level and one at the state level).
Such activity — exposing planes or helicopters to laser radiation — is a violation of federal law, as well as those in many individual states. Motives behind these acts remain unclear.
U.S. national laws, including FDA/CDRH: 21 CFR 1040.10/11, assert that it is illegal to aim laser pointer beams at aircraft or its flight path. Many states have enacted similar supplemental laws of their own. In Illinois, for example, all Class 3B and Class 4 lasers must be registered; it is a criminal offense to “discharge into cockpits.” In Maryland, it is a misdemeanor to knowingly aim a laser at any aircraft.
Safety and prevention
Laser-protective eyewear is recommended for pilots, beyond ordinary sun or “blue blocker” glasses. Blue blocker glasses have an effect on many different colors of blue and green, which may adversely impact how cockpit instruments and airport lights are perceived. Eyewear such as Laser-Gard from Sperian/Honeywell, LaserShields from NoIR Laser Co., Laser Armor from Night Flight Concepts and LaseReflect Aviator from Iridian Spectral Technologies are among available options.
While eyewear designed specifically for pilots can be useful, it does not block out all visible laser wavelengths. Some pilots may believe the chance of being illuminated is small and so they opt not to wear eyewear, especially if they know what steps to take if something like that happens: turn up cockpit lights, turn on auto pilot, look away and do not touch their eyes, as there is potential to scratch the cornea.
Illuminating aircraft with any type of laser pointer is an ongoing problem. Not only are perpetrators breaking the law by committing such acts, they are also putting people’s lives at risk — pilots, crew and the general public.
Meet the authors
Ken Barat is a laser safety consultant for Laser Safety Solutions; firstname.lastname@example.org. Josh Hadler is an award-winning physicist at the National Institute of Standards of Technology; email@example.com.
International regulatory response
Regulatory reaction to the misuse of handheld lasers has occurred in many countries. Here are some examples, courtesy of Laserpointersafety.com.
European Union, restrictions on laser pointers: On Nov. 3, 2010, radiation safety authorities in Finland, Iceland, Norway and Sweden asked the European Commission to “immediately begin preparing a European Directive for battery-powered lasers and establish import restrictions on such items.” The goal is to allow only Class 1 and Class 2 pointers; lasers above 1 mW would be restricted.
Australia, advisory circular for lasers and aircraft: The Australian Government’s Civil Aviation Safety Authority in April 2007 issued Advisory Circular AC 139-23(0), “Laser Emissions Which May Endanger the Safety of Aircraft.” This “provides general information and advice on measures to protect pilots of civil aircraft from accidental laser beam strikes, on or in the vicinity of an aerodrome.”
Canada, criminal code provisions: Under the Criminal Code of Canada, someone who points a laser at an aircraft could be charged with a number of different sections, depending upon the circumstances. Some of these sections carry significant penalties, up to and including life imprisonment. Such criminal charges could be laid in addition to the sections under the Aeronautics Act and Canadian Aviation Regulations.
Norway, possession and use regulation: As of Jan. 1, 2011, possession and use of laser pointers that are 5 mW and above is restricted by the Norwegian Radiation Protection Authority.
Sweden, possession and use regulations: The Swedish Radiation Protection Authority’s Regulations on Lasers, updated in 2008, bans the possession or use of lasers over 5 mW in public space. The relevant document is “SSMFS 2008:14.”
Information provided by Ken Barat.
U.S. national laws, regulations
•FDA/CDRH: 21 CFR 1040.10/11
•Illegal to aim laser pointer beams at aircraft or their flight path
•FDA/CDRH recommends aircraft/vehicle caution label
•FDA proposes changes to Federal Laser Performance Standard
•Radiation Control for Health and Safety Act of 1968
State and local laws, regulations
ARIZONA: Illegal to aim a laser pointer at a peace officer or an occupied aircraft
ARKANSAS: Law enforcement; minors
CALIFORNIA: Laser regulations
FLORIDA: Law enforcement and illuminating vehicles
FLORIDA: City of Leesburg bans laser harassment in 1999
GEORGIA: Illegal to aim at police, aircraft (proposed)
HAWAII: Illegal for anyone under 18 to possess laser pointers
ILLINOIS: All Class 3B and Class 4 lasers must be registered
ILLINOIS: Criminalize discharge into cockpits
ILLINOIS, county of Champaign: Possession and use are illegal
ILLINOIS, village of Westchester: Possession by minors banned
INDIANA: Laser pointer laws
LOUISIANA: Illegal to intentionally aim laser light at aircraft
MARYLAND, statewide: Misdemeanor to knowingly aim at aircraft
MARYLAND, town of Ocean City (2014): Ban on sales and possession; restriction on use
MARYLAND, town of Ocean City (2010): Ban and restriction on some uses, sales
MARYLAND, town of Ocean City (1998): Harassment prohibited
MICHIGAN, city of Dearborn: Unlawful to harass
MINNESOTA: Crime to aim laser into cockpit
NEW JERSEY, town of Ocean City (2011): Ban on laser pointer sales and possession
NEW JERSEY: Governor vetoes bill to ban laser pointer sales over 1 mW (2013)
NEW YORK CITY: Laser pointer regulations enacted
NEW YORK STATE: Illegal to aim a laser at an aircraft or its flight path
OREGON: “Unlawful directing” of a laser pointer
PUERTO RICO: Illegal to aim at aircraft or law enforcement officers
SOUTH CAROLINA: No sales to, or possession by, minors
SOUTH CAROLINA: Myrtle Beach restricts minors and misuse
SOUTH CAROLINA: Old North Myrtle Beach ordinance as of 2012
SOUTH CAROLINA: New North Myrtle Beach ordinance of 2013
TENNESSEE: Aiming a laser pointer at a law enforcement officer or similar
TEXAS: Law enforcement and aircraft illumination
UTAH: Unlawful use of a laser pointer
VIRGINIA: Interference with operation of aircraft
VIRGINIA: Illegal to aim lasers at law enforcement officers
VIRGINIA, city of Virginia Beach: Misdemeanor to aim into eyes