The first reported laser attack on an aircraft in the UK was in 2004. By 2008 this number had risen to over 200 attacks per annum. Since then, there have been about 1,500 attacks annually and, although this rate seems to be falling in the UK, the worldwide figure is rising year on year. Martin Drake examines the issue of lasers and what strategies and technologies are available to make the skies safer from them.
Aviation safety experts say lasers can be extremely dangerous to pilots, and therefore to the planes they fly. Pilots who have experienced an attack say that it’s like a lightning strike in that it is an instantaneous, very bright light, which is dazzling, distracting and can be disorientating. Aviation security experts say that shining lasers into cockpits presents a threat to the entire plane. Law enforcement officers are frustrated that often they do not have the powers to deal with the threat in an effective manner.
The first lasers were manufactured in 1960 by the Hughes Aircraft company. They were based on research that had taken place in 1958 at the Bell Laboratories and Columbia University.
A laser produces a highly collimated (the photons remain parallel and don’t diverge from each other) beam of single wavelength light; their early use seems to have been confined to range finding and scientific experimentation. When the first lasers went into production it was said that they were a solution looking for a problem to solve. Today there are over 55,000 patents involving lasers in the USA alone, they are truly useful pieces of technology, from engineering to medicine and from navigation to data storage. It is doubtful whether those early laser developers could have anticipated their use in firework shows or their ability to drive our pet felines to distraction.
Early lasers probably had a power of around 1 milliwatt (mw). Today it is possible to buy a laser 3,500 times that power. Uncontained laser pointers typically are used by lecturers, by amateur astronomers pointing out stars and constellations, and by those in the construction industry measuring or establishing level surfaces. Many countries around the world have legislation and procedures that make it absolutely clear that shining a laser at an aircraft is not just an annoyance, but a serious threat to the safety of the flight. They limit the power of pointers to an output of five milliwatts, but enforcement has proved to be somewhat more difficult than one would expect.
Many incidents occur during the take-off and landing portions of a flight, when the pilots need to be most alert. It has been reported that pilots have had to relinquish control of their aircraft to co-pilots during these attacks. In the case of law enforcement and emergency aircraft, there are reports that responses to crime scenes by airborne police units were terminated due to laser interference.
At first the threat was played down by almost all nation states, regulators and operators; “it is only a bright light, what’s the problem?” seemed to be their position. However shining lasers at any form of transport, never mind just aircraft, is incredibly dangerous. Even warnings from professional pilots’ associations to that effect were ignored. The British Airline Pilots’ Association said, ‘The power of these devices is increasing, and we’re concerned that, if left to escalate without significant intervention, we could see a serious incident happen in the near future.’ US ALPA was forced to take the issue to a high-level conference with government before action was eventually taken.
How to counter the threat is a problem that has attracted the attention of scientists and engineers and their considered opinion is that the best way forward, from their point of view, is to limit the amount of light reaching the pilots’ eyes. This can be done in essentially two ways: stopping the light entering the cockpit by adding filters to the windscreens, or preventing light reaching the pilot by supplying the pilot with special light-filtering spectacles.
Preventing light ingression may be done by applying a film to the windscreens of the aircraft. Much research has been carried out and there has been some success. Unfortunately, simple filters coloured at the correct wavelength also cut out a considerable amount of the light that pilots require to operate the aircraft safely, particularly at night.
“…stopping the light entering the cockpit by adding filters to the windscreens, or preventing light reaching the pilot by supplying the pilot with special light-filtering spectacles…”
Interference filters are designed to just cut out the wavelengths required. They have quite a narrow bandwidth, in the order of a few nanometres, thus a large amount of ambient light is allowed to pass. Yet, if the laser light strikes the film just away from the design angle it will pass through and dazzle could still occur. This can be addressed by increasing the bandwidth, however this would mean that ambient light would also be restricted, and the pilots would be in the same situation as using a simple filter. Current estimates suggest that the light available to the pilots would be reduced by 30%. Bearing in mind laser strikes tend to occur during the hours of darkness, this would be akin to wearing sunglasses at night. There is also a question around future proofing; as technology advances it is possible that the wavelength of lasers could alter, so films would need to be tuned or replaced to combat new threats.
There is also the issue of cost. Most developers are reluctant to put a price on their products, however current estimates are not too far away from $500 (c. £390) per square inch. This would represent a huge expenditure for each aircraft to the industry.
The alternative technology involves pilots wearing glasses and a lot of work has been done in this area. These have been moderately effective for military and law enforcement pilots and it is true that the latest generation are a quantum leap forward from early attempts. However, for civil commercial pilots, spectacles bring several challenges as they suffer from the same light transmission challenges as windscreen filters. In addition, they can and do remove some of the light transmitted from the electronic flight instrument systems (EFIS) that all modern aircraft use. EFIS displays convey far more than just navigational information and some elements of collision and windshear avoidance could be missed if the displays are not fully visible to the pilots. The concerns of commercial pilots about wearing spectacles when one does not need corrective lenses, or adding the laser-filtering glasses when one does, needs addressing in more than the cursory manner displayed up until now.
For both of these technologies there are also regulatory issues which, as yet, have not been adequately thought out. So where does that leave the industry? We need to develop adequate strategies to offset the deleterious effects of the laser illumination of aircraft. Such strategies need to be multifaceted and involve agencies that might not, at first sight, be directly connected with aviation.
Countries’ equivalents of trading standards can be very proactive in making sure that all lasers are imported and used for their intended purpose. Multifunctional lecturing wireless laser pointers made by reputable firms are well within allowable limits and highly unlikely to be a threat. Similar cheap copies bought from certain internet sellers tell a different story; they are very much more powerful and often incorrectly labelled. The importation and sale of lasers should be closely monitored and controlled.
“…some elements of collision and windshear avoidance could be missed if the displays are not fully visible to the pilots…”
Andrew Haines, when he was the chief executive of the regulator, told the Press Association: “Why does Joe Bloggs walking down the street need a laser that can pop a balloon at 50 miles, that can cause permanent damage to a pilot?”
Education is essential, it is difficult to find a sensible reason for members of the public to have in their possession a powerful class four laser. They are extremely dangerous and it is incumbent on governments, as some do, to provide their citizens with the knowledge to make informed decisions about laser ownership. Schools and colleges can be engaged as can the social media that is of interest to parents. The US Air Line Pilots Association (US ALPA), in collaboration with the FBI and the FAA, on 11 February 2018 launched a 12-city public awareness campaign about the safety issues surrounding laser attacks on aircraft cockpits.
To help jump-start the campaign, the FBI is offering a considerable reward for information leading to the conviction of anyone caught laser-lighting an aircraft in the U.S. ALPA also convinced lawmakers to make laser illuminations a federal crime now punishable by a fine of up to $250,000 (£200,000) and up to five years’ imprisonment. The FAA can also impose civil fines of up to $11,000 (£9000) per laser incident.
The law enforcement community must be given the tools to investigate and prosecute offenders. Whilst there is no suggestion that citizens should be routinely stopped and searched, there should be adequate provisions to insist that someone found in possession of a laser should have to explain why they have such a device about their person. It is worth the police being aware that a laser illumination event can result in effects that could be a safety hazard to the aircraft from such effects as: temporary vision loss associated with flash blindness – a visual interference that persists after the source of illumination has been removed; after-image – a transient image left in the visual field after exposure to a bright light; glare – obscuration of an object in a person’s field of vision due to a bright light source located near the same line of sight. Thus, someone illuminating an aircraft with a laser is potentially endangering the flight. Legislation exists to prosecute offenders and should be used.
Pilots can take some measures in the event of an incident. They are advised to shield their eyes from the light source with a hand or a hand-held object and avoid looking directly into the beam. It is possible that a laser successfully aimed at the flight deck will be presaged by unsuccessful attempts to do so. These will be seen as extremely bright flashes coming from the ground and/or visible in the sky near the aircraft. Pilots should treat these flashes as a warning they are about to be targeted and prepare to shield their eyes. They should not look in the direction of any suspicious light.
Alerting other crew member(s) by using the phrase “laser attack” (initially assuming having been deliberately targeted and anticipating further illuminations) is the protocol and determining whether they too have suffered any laser-related effects. If the other front seat pilot has not been affected, he or she should immediately assume or maintain control of the aircraft.
“…a federal crime now punishable by a fine of up to $250,000 and up to five years’ imprisonment. The FAA can also impose civil fines of up to $11,000 per laser incident…”
Those impacted by the ‘attack’ should avoid rubbing their eyes thereby reducing the potential for corneal abrasion. Pilots should manoeuvre to block the laser, if possible and subject to ATC coordination, and, if on approach, consider a go-around. Other responses include engaging the autopilot; after regaining vision, to check flight instruments for proper flight status; turning on flight deck lighting to maximum brightness to minimise any further illumination effects; consider declaring an emergency and, in any event, immediately report the laser strike to ATC, including the direction and location of the laser source, beam colour and length of exposure (flash, pulsed and/or perceived intentional tracking). That said, it is important not to look directly into the beam to locate the source.
ATC should regard a laser illumination incident as an in-flight emergency and will treat them as such. There should be a duty on ATC to share that information through normal communications with safety agencies and the police. Air traffic controllers will then work with the police to identify the source of the lasers to ensure a rapid police response to the scene. Other flights should be warned that there has been laser activity in the area so that crews can prepare for a potential strike. It is also essential that pilots file a report so that the true size of the problem can be ascertained, and resources directed appropriately.
One other factor to be considered is the continuing health of the pilots. This is especially important if the crew are in the middle of a tour of duty, when medical advice should be sought as soon as possible. If rostered for further flight sectors, pilots should consider whether they are physically and psychologically still fit to fly even if their own self-assessment indicates no visual impairment. It is for individual flight crew to determine their fitness to fly in such circumstances, regardless of operator policy.
Given the many incidents of cockpit illuminations by lasers, the potential for an accident definitely exists, but the fact that there have been no laser-related accidents to date (November 2018) indicates that the hazard associated with current lasers can for the time being be successfully managed. As the laser power increases, however, so does the concern surrounding potential outcomes. Technologies are available to mitigate the effects of lasers, but are still immature, do not provide full-spectrum protection and are unlikely to be installed on airline flight decks in the foreseeable future. In the meantime, the threat is most likely to be managed by the development and use of effective operational strategies, by continuous education, appropriate import controls and bringing offenders to court.
Captain Martin Drake is the Chairman of both the British Air Line Pilots’ Association and the European Cockpit Association Security Committees. He is a long-serving member of the IFALPA Security committee. He addresses the security concerns of more than 40,000 European professional pilots and sits on various government committees both in the UK and the EU, advancing pilots’ views with the anti-terrorist and security agencies, as well as advising on the strategies that may be considered when police and airports are faced with security situations. He also advises on the hazards that RPAS and lasers represent to conventional aviation assets. Capt. Drake is in current flying practice as a B747 captain based in the UK, having also flown the B737 series, the Twin Otter for the British Antarctic Survey, and various general aviation aircraft.