Under certain conditions, laser light or other bright lights (spotlights, spotlights) directed at the aircraft may be a danger. The most likely scenario is when a brightly visible laser beam causes temporary flash interruptions or blind flashes to the pilot, during critical flight phases such as landing or take-off. This is much less likely, though still possible, that visible or invisible rays can cause permanent damage to the pilot's eyes. Although laser weapons are being developed by the military, this is very special, expensive and controlled making it impossible for non-military lasers to cause structural damage to aircraft.
Aviation hazards from bright light can be minimized or eliminated in two main ways. First, users in the field can be careful, to prevent or minimize laser light or other bright lights that are directed in the air space and especially toward the plane. Secondly, the pilot must have awareness of the dangers of laser/aviation and knowledge of basic recovery procedures in case of laser or exposure to bright light.
Pointing lasers on an aircraft can be dangerous for pilots and has resulted in arrests, trials and imprisonment. It also generates calls for license or prohibition of laser pointers. Some jurisdictions such as New South Wales have limited laser pointers as a result of several incidents.
Video Lasers and aviation safety
Laser and bright lights
In addition to lasers, other bright lights like spotlights and spotlights can have the same dazzling, distracting, and mesmerizing effect. Highlight and spotlight operators should take the same basic precautions as laser users. Similarly, pilots and safety officials should keep in mind that reported "laser" incidents may be caused by non-laser light.
Maps Lasers and aviation safety
Laser in airspace
There are many valid reasons that the laser is directed to the air space. Lasers are used in industry and research, as in atmospheric remote sensing, and as "guiding stars" in adaptive optical astronomy. Lasers and spotlights are used in entertainment; for example, in outdoor shows such as the IlliaNations night show at Walt Disney World Epcot. Laser pointers are used by the general public; sometimes they are intentionally or unintentionally directed to or near the plane. (Of course, no unauthorized person should intentionally direct any type of laser on or near an aircraft.)
Lasers are even used, or proposed for use, by airplanes. The pilot is lost to an unauthorized airspace in Washington, D.C. can be warned to come back by turning on a low-eye green and green laser on them. At least one system has been tested that will use lasers in the final approach to help deliver the pilot on the right glideslope. NASA has tested the Helicopter Airborne Laser Positioning System. The FAA has tested the laser line projected on the airport runway, to improve the visibility of the "short-term" sign.
Due to these various uses, it is impractical to ban the laser from the air chamber. This will severely restrict legitimate use, it will not prevent accidental lighting incidents, and it will not stop a person who is intentionally, out of envy or ignorance, the targeted aircraft. For this reason, laser/flight safety is practically based on informed users and informed pilots.
The main danger of laser and bright light
(Note: The photos on the right are blinking because most incidents are flash and not a stable illumination.In accidental illumination there may be only one or several flashes.Even in deliberate illumination, it is difficult to hand - hold the laser on the moving target, so there will be a series of longer blinks With a helicopter at close range, it is possible to have more or less sustained light The flashes shown greatly exaggerate the duration of laser flash and use green instead of red light which is less visible.With planes traveling hundreds of miles/hour and the size of a laser beam only one meter or more, the duration of the flash will be measured in thousandths of a second.)
There are some subjects that laser security experts/airlines agree does not pose a real danger. These include laser passenger exposure, pilot interruption during sailing or non-critical flight phases, and laser damage to aircraft.
The safety expert's primary concern is almost exclusively focused on lasers and bright light effects on pilots, especially when they are in the critical phase of flight: takeoff, approach, landing, and emergency maneuvers.
There are four main areas of concern. The first three are "visual effects" that distract temporarily or block the pilot's vision. This effect is only a concern when the laser emits visible light.
- Distractions and surprises. Unexpected bright laser or light can distract the pilot during landing at night or take off. A pilot may not know what happened at first. They may worry that a brighter light or other threats will come. It is important that pilots are trained to understand the relatively small impact of laser sparks caused by laser pointers and do not overreact.
- Glare and disturbance. As the brightness of the light increases, it begins to interfere with vision. Glare of the glare will make it difficult to see the windshield. Night vision is getting worse. The laser beam is so direct that the pilot can act to extract sources from their direct field of vision if properly trained. Laser pointers have an illumination of about 1 lumen/m2 whereas during the day the pilot has to deal with sunlight a hundred thousand times stronger.
- Flash blindness is temporary. It works exactly like a bright camera flash: no injuries, but night vision is disconnected. There may be afterimages - again, just like a bright flash camera that leaves the place temporarily.
The three visual effects above are the main concern of aviation experts. This is because they can happen with low-powered lasers that are generally available. The fourth concern, eye damage, is very unlikely. Special equipment is required that is not available to the general public.
- Eye damage. While not possible, high-visible or invisible laser (infrared, ultraviolet) rays can cause permanent eye injury. The injury can be relatively small, as freckles are only detected by medical examinations or on the periphery of vision. At higher power levels, the point may be in central vision, in the same area where the original light is seen. Most unlikely of all is the injury that causes complete and permanent loss of vision. To do this requires very special equipment and a desire to deliberately target the aircraft.
It is highly unlikely that any of the above four elements will cause a loss of aircraft, especially if the pilot reacts correctly and works as a team.
Analyzing the hazard
The US FAA has studied several of these factors. They did pilot research in a flight simulator to determine the effect of laser exposure on pilot performance; The results were released in August 2003 and June 2004.
Example of laser security calculation
The graph (right) shows many important laser/flight safety concepts. For example, this indicates that the area of ​​greatest concern - eye damage, lightning blindness and glare - occurs relatively close to the plane. The risk of disturbance includes the longest distance of danger, but fortunately also presents the least attention. The photographs in the graph also provide an overview of what a visual effect looks for pilots, at various distances.
Note that while the given distance is appropriate ("52 feet", "262 feet"), laser brightness actually falls slowly. Unlike in the 51-foot laser is an eye hazard and at 53 feet it is a safe eye. Effects are reduced continuously with increasing distance.
Also, a weaker effect is part of a stronger effect. Even if the laser does not cause eye damage at 25 feet, it can still cause lightning blindness, glare and disorder.
For each given laser, the relative distances shown here are subject to change. For example, invisible (infrared) lasers can be an eye hazard for hundreds of feet, but do not present lightning blindness, glare or interruption. Therefore, each laser must be analyzed individually.
To give another example, here is a stronger laser calculation - the kind that might be used in outdoor laser shows. A 6-watt green laser (532 m) with 1.1 milliradian light aberration is an eye hazard up to about 1,600 feet (490 meters), can cause lightning blindness up to about 8,200 feet (1.5 miles/2.5 km), causing glare veil to the eye. about 36,800 feet (7 miles, 11 km), and is a distraction of about 368,000 feet (70 miles, 110 km).
Reduce the hazard
There are a number of ways that laser users, regulators and pilots reduce the potential dangers of outdoor laser use. These steps include:
Police enforcement
Police start using helicopters to patrol and search for people using lasers to disrupt flights.
User harm reduction actions
- Use the lowest power needed for a task.
- Increases the beam deviation. The rays spread faster, so at a certain distance, the amount of light entering the eye or the cockpit's windshield will decrease (eg, lower radiation).
- Keep blocks away from areas with multiple planes, such as airports and flight paths.
- Stopping blocks on buildings, solid trees, etc. to prevent the laser beam from entering the protected airspace. This is a general measure of protection for outdoor laser shows, if there are structures available for termination.
- Use spotters to watch planes. This is usually done for laser shows that tend to be short (about an hour) and rarely (rare night events).
- Use an automatic detection system like a radar camera or sky camera. It is used for long (overnight) and frequent (night) applications, such as laser guide stars used in astronomical observatories.
- Develop and follow policies for outdoor laser surgery, such as the ANSI "Nasa Outdoor Safe Use" or "NASA Use Policy" for Outdoor Lasers. "
Regulatory hazard mitigation measures
- Limit the sale or use of laser devices. This is done in some jurisdictions. For example, in April 2008 New South Wales, Australia prohibited the possession of laser pointers, except with special permission, in an attempt to reduce the number of laser illumination planes. In October 1997 in the UK, administrative measures were taken to limit the sale of laser pointers & gt; Output of 1 miliwatt, for the same reason (although the purchase, import and use of such a pointer in the UK remains valid). In the US, the Congressional Research Service noted that the ban could "pose significant challenges because these devices are widely available at low cost and are used in applications such as laser pointers, laser levels and laser gun sight.
- Requires review or approval of outdoor laser use. These are discussed in the Rules and control section below.
- Amending existing laws, or setting new ones, to try to prevent irresponsible laser use. One of the US federal efforts in this direction is "Securing Aircraft Cockpits Against the Laser Act of 2005", discussed in the History section below.
- Following a series of laser-caused accidents, the state of Arizona passed Bill 2164 (2014) which made it a First Class crime to drive the laser into an airplane.
Pilot/aircrew reduction measures
- Fixed Laser installations (eg star laser guides from the observatory) can be tagged on the flight charts so that pilots are aware of potential beams along their flight path. Temporary use (laser show) can be explained in the pre-flight information. For example, in the US, the use of lasers delivered to the FAA is often listed in NOTAMs for pilots.
- Education and training. The SAE G-10T Laser Hazards Subcommittee works on the Recommended 5598 Aerospace Practice document, "Visual Laser Interference - Pilot Operational Procedure." This will provide information for pilots about recognizing and recovering from laser incidents or bright light. Articles in aviation publications have also provided useful information, such as "Laser Illumination: Last Line of Defense - Pilot!".
Active hazard reduction (proposed steps)
Several measures have been proposed to protect aircrews including glasses and glass filters. It can work in theory (especially against known wavelengths) and may be useful in some situations such as military operations. However, these measures may not be suitable, practical or recommended for widespread civil air operations.
- Laser safety glasses. Laboratory-type laser safety glasses are not suitable for pilot operations. "The transmission rate of 20% of laboratory laser glasses may have a catastrophic effect on the cockpit crew who must read the instrument while flying at night.The optical quality of the system is also a factor because little distortion or fog that may not have concern in the laboratory may be a major concern pilots flying at low altitude and high speed. "Also, there may be a variety of laser wavelengths/colors that may need to be maintained. If all wavelengths are protected, the glasses are essentially opaque. There are also problems with the discomfort of wearing glasses on a regular basis, given that laser incidents are relatively rare.
- Active "smart" glasses that can detect laser light and then activate blocking/dimming processes based on strength and wavelength. It is unknown whether this is in production or use; if so, this possibility is only used in military applications.
- Glare shield that can be pulled down the windshield to reduce all incoming light.
- Laser detector/recorder that can detect laser illumination and record information about wavelength and power. It provides no protection but provides information about illumination that may be useful for later analysis or legal action.
Settings and controls
In the United States, airspace laser guides can be found in the Federal Aviation Administration Order JO 7400.2, Chapter 29 "Outdoor Laser Operations", and a light air space guide in Chapter 30 "High Intensity Light Operations".
In the United Kingdom, CAP 736 is "a Guide to Laser Operations, Highlights, and Fireworks in the United Kingdom."
For all laser users, the ANSI Z136.6 document provides guidance for the safe use of outer lasers. Although this document is copyrighted by ANSI and its price is relatively expensive, a taste of its recommendations can be found in NASA's Outdoor Laser Usage Policy.
Air space zone
The US FAA has established an air zone. It protects the area around the airport and other sensitive airspace from the dangers of laser exposure that look too bright and safe:
- Laser Free Zone expands immediately around and above the runway, as illustrated to the right. The irradiated light in the zone should be less than 50 nanowatt per square centimeter (0.05 microwatt per square centimeter). This is set at "levels that will not cause visual disturbance."
- Critical Flight Zone includes 10 nautical miles (NM) around the airport; the limit of light is 5 microwatt per square centimeter (? W/cmÃ,²). This is "determined to be the level at which significant glare problems can occur."
- The Sensitive Zone Aviation option is set by the FAA, military or other aviation authority where the light intensity should be less than 100? W/cmÃ,². This can be done for example around a busy flight path or where a military operation is taking place. This "is identified as the level of exposure in which significant flash blindness and afterimages can interfere with the pilot's visual performance."
- Normal Aviation Zone covers all other airspace. The intensity of light should be less than 2.5 milliwatts per square centimeter (2500? W/cmÃ,²). This is about half of the 3R Class power level, and is not considered
For invisible (infrared and ultraviolet) lasers, radiation on the aircraft must be safe against the eye - below the maximum Exposure Level Allowed for that wavelength. For lasers that look pulsed, radiation on the aircraft must be eye-safe and should be at or below the prevailing FAA laser zone.
In the UK, restrictions are imposed in zones that include 3 nmi circles (5.6 km km) within radius around the aerodrome (airport) plus extensions from each end of each runway. The runway zone is a rectangle 20Ã, nmi (37 km km) with a total length and 1,000 meters (3,300 feet) wide, centered on each runway.
Reporting
In the US, people who operate outdoor lasers are required to file a report with the FAA at least 30 days in advance, detailing their laser strength. They must refer the location of their operations in connection with the local airport and describe the power of lasers emitted in the Sensitive, Critical, and Laser Free zones. Note that it is possible to use lasers whose output exceeds these zone boundaries, if other control measures already exist. For example, complainants can be used to keep an eye on an airplane, and shut down lasers if potential conflicts are seen. (This raises separate issues regarding the number, training and effectiveness of complainants: FAA must be sure that the issue is answered for a particular operation.)
FAA Advisory Circular 70-1 "Outdoor Laser Operations" contains two forms plus hints. One form is "Proposed Laser Operating Notice", another is a "Laser Configuration Worksheet" filled for each laser or any different laser configuration. The FAA will review the report, and will send a letter of objection or will send a letter of no objection. Language is important; The FAA does not "approve" or "disagree" because it implies a higher regulatory authority that the FAA does not own.
If the use of laser for a show or display in the US, there is a more rigorous regulatory process. In the US, any laser use in the event or display requires prior approval from the FDA Center for Devices and Radiological Health. This is necessary both for laser equipment, and separately for the show itself (site, audience configuration, light effects, etc.). As part of the CDRH approval process ("variance"), CDRH will request an objectionable letter from the FAA. Without this, laser performances can not proceed legally.
In the US, laser activity in certain areas is communicated to the pilot before their flight through NOTAM. Pilots exposed to laser or light during flight must follow Circular 70-2 "Laser Illumination Reporting Service".
UK laser operators report outdoor laser, spotlight or firework operations at least 28 days in advance, using the Notice Form contained in Appendix A of the 736 CAP document.
Development of rules and standards
The main group in the US that works for laser/flight safety is SAE G-10T, Laser Safety Hazard Subcommittee. It consists of experts and researchers of laser safety, pilots and other interested parties representing military, commercial and personal flights, and laser users. Their recommendations have formed the basis of the rules and forms of FAA lasers and bright light, as well as standards adopted in other countries and by ICAO.
The ANSI Z136.6 standard is "American National Standard for Safe Use of Outdoor Lasers." The Z136.6 committee has been working with SAE G-10T and others, to develop safety procedures recommended for outdoor laser use.
History
Until the early 1990s, laser flight incidents and bright light were sporadic. In the US, NASA's Flight Safety Reporting System shows only one or two incidents per year. The SAE G-10T subcommittee began meeting around 1993 when the number of incidents increased. Almost all incidents are known or suspected because of outdoor laser screens. Almost all concerns are potential eye damage; at that moment the visual effects are perceived to be of little consequence.
In late 1995, a number of lighting incidents occurred in Las Vegas because of the new outdoor laser screen. Although displays have been approved by the FDA as eye-safe for their airport proximity, no one notices that glitches/distractions will adversely affect pilots. In December 1995, the FDA issued an emergency order to shut down the Las Vegas show.
In the SAE G-10T subcommittee, there are some considerations about reducing or banning laser performances. However, it became clear that there were a large number of non-entertainment laser users as well. The focus shifts to known laser user controls, whether show or industry/research. New policies and procedures are developed, such as FAA 7200 Chapter 29, and House of Representatives 70-1. Although incidents continued (from January 1996 to July 1999, the FAA West-Pacific Region identified more than 150 incidents where low-flying aircraft were illuminated by lasers), the situation seemed to be under control.
Later in late 2004 and early 2005, there was a significant increase in reported incidents related to laser pointers. The incident wave may be partly triggered by an "impersonator" who reads a laser pointer incident report. In one case, David Banach of New Jersey was indicted under federal Patriot Act anti-terrorism laws, after he allegedly shone a laser pointer on the plane.
In response to the incident, the Congressional Research Service released a study of laser "threats to aviation safety and security." Because there is no federal law that specifically prohibits the deliberate laser lighting of aircraft, Congressman Ric Keller introduced Hr 1400, "Securing the Cockpits Against Laser Act of 2005." The bill was passed by the House of Representatives and the US Senate, but did not go to the conference and thus did not become a law. In 2007, Keller reintroduced the bill as H.R. 1615. Though endorsed by the Parliament in May 2007, Keller was not followed up by the Senate before the expiration of the 110th Congress and never became law.
On March 28, 2008, a "coordinated attack" took place using four green laser pointers aimed at six aircraft landings at Sydney's Sydney (New South Wales) airport. As a result of these and other attacks, a law was proposed in mid-April 2008 in NSW to ban the ownership of hand-held lasers, even "harmless class pointers". The state of Victoria in Australia is reported to have a similar ban since 1998, but press reports state that it is easy to buy lasers without permission.
On February 22, 2009, a dozen aircraft were targeted with green laser beams at Seattle-Tacoma International Airport. An FAA spokeswoman said there were 148 laser attacks on aircraft in the US from January 1, 2009 to February 23, 2009.
During the July 2013 protests of the Morsi Presidency in Egypt and then celebration of his dismissal, thousands of protesters and followers directed laser pointers to government helicopters.
In February 2016 Virgin Atlantic flights from Heathrow to New York's JFK Airport were forced to return when laser light shone into the cockpit. The incident caused BALPA to call the laser to be classified as an offensive weapon.
See also
- Dazzler (weapon)
- Laser security
- Laser pointer
External reference
- FAA Order JO 7400.2L, Procedures for Handling Airspace Problems, effective 2017-10-12 (with changes), accessed 2017-12-04 (quoted as "FAA JO Order 7400.2")
References
Source of the article : Wikipedia
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