Laser pointers blinding pilots? Sounds implausible

[salimfadhley]

According to this article the "new" hand-held green laser pointers have been used by naughty kids/terrorists to blind pilots:

http://www.theinsider.org/news/article.asp?id=872

"You're in an airplane, you're on final approach and suddenly you can't see," said Dan Kidder, a spokesman for the National Air Transportation Association, a trade group. "You can't see your instruments. You can't see your runway. There's the potential for a major accident."

Does that seem plausible? I remember using hand-held lasers as a child in Physics lessons. We were always told not to stare directly into the beam, but they were not hugely bright and the optics were of poor quality meaning that by ten m from the soruce the beam had noticeably diverged.

Supposing somebody were to aim an excellent quality handheld laser at the cockpit of a flying aircraft: I'm guessing any "hit" on a pilot's eye cannot be more than instantanous. What's the possibility that it could blind? It seems rather remote to me.

Furthermore, the pilot would see the laser as a single point of light: Like a green dot on the horizon. At worst surely this could cause very localized retinal overload (like staring into a table-lamp for a second) but not the kind of blindness where you cannot see a thing.

And if this were true:
http://news.scotsman.com/uk.cfm?id=1416162004

Why bother with all that dangerous mucking about with easily discovered explosives when all you need t do is shine a light at an aircraft and watch it tumble helplessly from the sky? If that were true then the military would never bother with conventional anti-aircraft weapons.

[ZERO]

Even worse.... http://sportal.com.au/football-news-display/kuwait-laser-probe-83755

[polomint38]

This could cause serious damage to ZERO, being just an eye. ;D

[salimfadhley]

Even worse.... http://sportal.com.au/football-news-display/kuwait-laser-probe-83755

This does sound somewhat plausible: I can imagine that if you are less than 100m from the source of laser light then it could be really distracting. That could be a serious problem if your business is accurately kicking balls. I reckon it would be really easy to spot exactly who was shining the light - you'd see a red dot even if it wasn't pointed exactly at your eyes.

On the other hand, unless the light was very bright indeed I doubt it would be visible beneath the stadium lights and flashbulbs going on.

A pilot friend @sounddoc twittered (just now) that the whole laser-pointer blinding pilots story is BS: A pointer would be ineffectual during the day and at night landing lights (which are designed to be visible in heavy fog) are considerably brighter than any hand-held laser-pointer.

[Tony Williams]

A few months back, during a news report about someone jailed for this offence, they showed a view from the air while someone on the ground was shining one of these lasers up at the plane. It was very dazzling, and would certainly have been a major distraction at a crucial moment when in the final stages of landing.

[skbuncks]

Perhaps not so BS afterall.

http://www.usatoday.com/news/washington/2005-01-11-laser-aircraft_x.htm

skb

ETA:
A wide range of people are believed to have been behind the incidents, Mineta said.
"Stupidity is not something monopolized by any age, or sex," he said.
lol

ETA2: http://news.smh.com.au/national/laser-pointers-restricted-after-attacks-20080406-240f.html
and the ban in Australia, brought about in pat due to the targeting of aircraft http://www.customs.gov.au/site/content10444.asp (http://www.customs.gov.au/site/content10444.asp)

[Legaleagle]

http://www.hf.faa.gov/docs/508/docs/cami/0107.pdf


I think the use of the word "blinding" in media reports is inappropriate. What we are talking about is temporary impairment of vision and distraction, which could lead to a pilot making an error.

[Cuddles]

Does that seem plausible? I remember using hand-held lasers as a child in Physics lessons. We were always told not to stare directly into the beam, but they were not hugely bright and the optics were of poor quality meaning that by ten m from the soruce the beam had noticeably diverged.

As is usually noted in the news articles about this, the lasers in question are generally far more powerful than ordinary classroom pointers. One of the more common legitimate uses is for aiming telescopes, where having a beam able to reach hundreds of metres into the air can be very useful. Given that the problems are only caused for low flying aircraft, usually taking off or landing, that's enough range to be a real problem.


Supposing somebody were to aim an excellent quality handheld laser at the cockpit of a flying aircraft: I'm guessing any "hit" on a pilot's eye cannot be more than instantanous. What's the possibility that it could blind? It seems rather remote to me.

As Legaleagle points out, they don't mean that it causes permanent blindness, merely that it can dazzle them for anywhere from a few seconds to several minutes. When flying an aircraft, especially during the fiddly bits near the ground, that can be plenty to cause trouble.


Furthermore, the pilot would see the laser as a single point of light: Like a green dot on the horizon.

How narrow do you think the beams are? Even very close it's easily the size of your pupil. Of course, your claim here is hardly consistent with your earlier claim that these pointers have low power beam that have diverged a lot within 10s of metres.


At worst surely this could cause very localized retinal overload (like staring into a table-lamp for a second) but not the kind of blindness where you cannot see a thing.

You don't need to be completely blind in order to be unable to read your instruments.


Why bother with all that dangerous mucking about with easily discovered explosives when all you need t do is shine a light at an aircraft and watch it tumble helplessly from the sky? If that were true then the military would never bother with conventional anti-aircraft weapons.

Obviously planes don't magically drop out of the sky the instant the pilot has a little trouble with his vision, and I've never seen anyone suggest that to be the case. That doesn't mean that there can't ever be any danger from doing this.

Quite frankly, it doesn't seem as though you're particularly interested in honest debate here. You're indulging in the most ridiculous hyperbole apparently without having done the most basic research. Yes, some laser pointers are easily powerful enough to cause problems with vision. Yes, having problems with vision is not a good thing when flying a plane. No, laser pointers aren't some magic weapon able to instantly destroy any aircraft they're pointed at. Seriously, what argument are you trying to make here?

[salimfadhley]

As is usually noted in the news articles about this, the lasers in question are generally far more powerful than ordinary classroom pointers. One of the more common legitimate uses is for aiming telescopes, where having a beam able to reach hundreds of metres into the air can be very useful. Given that the problems are only caused for low flying aircraft, usually taking off or landing, that's enough range to be a real problem.

I'm not denying that it's theoretically possible to aim a sufficiently powerful laser at a pilot's eye and cause temporary dazzling. I am sceptical that it has every actually happened as a consequence of a cheap hand-held laser pointer, the kind they said could be bought for around $5.

Note the heading of the thread. I will say it again, that I fully understand that lasers are potentially dangerous things. I even know that defence companies have been attempting to build blinding weapons from lasers, however the title of the article I was responding to was "Cheap laser pointers from eBay used to blind aircraft pilots".


As Legaleagle points out, they don't mean that it causes permanent blindness, merely that it can dazzle them for anywhere from a few seconds to several minutes. When flying an aircraft, especially during the fiddly bits near the ground, that can be plenty to cause trouble.

This is my other problem:

We all know that a prolonged direct hit to the eye can cause dazzling or even permanent damage. The amount of time required to dazzle or damage depends on the power of the beam and the degree to which the beam has attenuated or diverged. We also have the problem of aiming the beam: Supposing I were to try and aim at the eye of a pilot 50m away (which we all agree is fairly close range) - the subtle motion of my hand will mean the dot will be dancing about wildly around the target. Even variations in air pressure can cause a measurable deflection over 50m. Unless the laser was very powerful, the chance of this connecting with the pupil for long enough to cause even dazzling still seems unlikely at handheld powers.

And let's not forget: We are trying to target a moving object. The only position from where this would be an 'easy' hit would be if you were directly in it's flight path: For example, if you were standing just beyond the runway and shining a laser as the plane was coming in to land.

Note once again that I'm not denying that it would be distracting or worrying. A pilot might assume that he was being targeted by some kind of weapon system. Somebody once shone a laser pointer at me while i was cycling around London. It was disconcerting.


How narrow do you think the beams are? Even very close it's easily the size of your pupil. Of course, your claim here is hardly consistent with your earlier claim that these pointers have low power beam that have diverged a lot within 10s of metres.

At school (more than 20 years ago) the physics department had acquired a number of red lasers. At source the beam diameter seemed to be less than 1mm, however by 15 metres the lasers projected a thin line of length .75cm to 4cm on the wall. I guess it was due to optical flaws in the source's lens. I've noticed that most cheap semiconductor lenses have some degree of divergence due to optical flaws at the interface between the laser and the air.


Obviously planes don't magically drop out of the sky the instant the pilot has a little trouble with his vision, and I've never seen anyone suggest that to be the case. That doesn't mean that there can't ever be any danger from doing this.

See my comment below:


Quite frankly, it doesn't seem as though you're particularly interested in honest debate here. You're indulging in the most ridiculous hyperbole apparently without having done the most basic research. Yes, some laser pointers are easily powerful enough to cause problems with vision. Yes, having problems with vision is not a good thing when flying a plane. No, laser pointers aren't some magic weapon able to instantly destroy any aircraft they're pointed at. Seriously, what argument are you trying to make here?

Any hyperbole was intended to summarize the articles I linked to - they presented cheap consumer lasers as an immediate, significant risk to air-travel.

I fully accept that the beam from high-power lasers are visible from aircraft (there's youtube videos to prove it). Furthermore I accept that :
* a direct, prolonged hit,
* from a sufficiently powerful laser,
* at sufficiently close range,
* or with an accurate aiming system

... could could cause dazzling or possibly permanent eye-damage to an occupant of any vehicle with a window.

I do not think the above is ever likely to be the case when the laser-operator is outside an airport perimeter and using a cheap hand-held battery-operated laser pointer and the target is a plane in motion.

[salimfadhley]

Another thought just occurred to me:

What's so special about lasers? Any sufficiently bright light can be distracting. If you take a not so bright light and flash it quickly enough it can be annoying or even trigger seizures. There are hand-held LED flash-lights which can produce brighter beams which are visible from great distances. Drivers are often distracted by roadside adverts or particularly attractive members of the opposite sex. Even forgetting to dip your beam for oncoming traffic is enough to cause temporary dazzling.

When you start listing 'em there are plenty of common things which are known to distract vehicle operators.

Compared to the above, I feel that the evidence to support the laser stories seems very weak. :-)

[Tony Williams]

I fully accept that the beam from high-power lasers are visible from aircraft (there's youtube videos to prove it). Furthermore I accept that :
* a direct, prolonged hit,
* from a sufficiently powerful laser,
* at sufficiently close range,
* or with an accurate aiming system

... could could cause dazzling or possibly permanent eye-damage to an occupant of any vehicle with a window.

I do not think the above is ever likely to be the case when the laser-operator is outside an airport perimeter and using a cheap hand-held battery-operated laser pointer and the target is a plane in motion.
It's more serious than that. First of all, a "sufficiently powerful laser" at "sufficiently close range" can cause permanent blindness instantly, and I recall reading that it has done so in laboratory accidents. Laser weapons have been developed to do just that, see page three of this: http://www.allbusiness.com/specialty-businesses/492548-1.html


"Laser weapons, which are likely to be relatively inexpensive and light-weight, can be mounted on assault rifles and used to scan the field in front of the attacker. At a distance of one kilometer, which is within the weapon's range, the invisible beam will spread to a width of at least 50 centimeters. Anyone within that range who glances at the beam, be it a soldier, a journalist a nurse or a civilian, will be blinded instantly."

This does, of course, describe rather more than a cheap commercially-available one. However, as I have already posted, there was a practical demonstration in a news clip of the effect of one of these cheap, hand-held lasers aimed from the ground at an aircraft passing overhead. The beam merely flashed across the camera lens for a moment, but all that could be seen at that instant was a brilliant flare of green light. I can well believe that a pilot hit in the eyes by such a beam, even for an instant, would have his vision impaired for a few seconds.

I'm not sure what point you're trying to make with the "any vehicle with a window" comment. Dazzling the pilot of an aircraft which may have hundreds of passengers on board, just as it's coming into land, is a damn sight more serious than dazzling a car driver, who can slam the brakes on and stop...

IMO it is rightly considered a serious act, punished severely.

[Pebble]

IMO it is rightly considered a serious act, punished severely.

But the US military has now admitted shining lasers at aircraft as part of a secret programme:

A day after the Department of Transportation urged pilots to report hazardous laser beams aimed at aircraft, the U.S. military said it is testing a system to beam red and green lasers at aircraft in the Washington area as a warning when they enter restricted airspace.
Source: Washington Post, "Military Tests Lasers To Warn Off Aircraft", 14 Jnauary 2005.
http://www.washingtonpost.com/wp-dyn/articles/A7708-2005Jan13.html


I wonder about this. Lasers come in many forms, very high energy lasers can burn anything, military style lasers can track moving objects such as cockpits, and your article suggests that widefield lasers are being developed by the military. With these high end versions it is easy to see the potential use to terrorists, but harldy useful to pranksters.

Now jumping down the throat of some teenagers looking for kicks based on what the military have produced and might become available to terrorists, looks like an example of bullying those you can because of generic unfocused fear.

If you want to convince me that there has bee a serious transgression, I would want some evidence that standard handheld lazers (or what ever the kids were using) has been shown to be capable of disabling/severely distracting, when pointed at an object several hundred meters away moving at 80+ miles per hour. Further I think we need to factor in the fact that there is a co-pilot, and multipile automatic controls to prevent crashing.

[chaggle]

Shining bright distracting lights at landing aircraft? It doesn't matter if the risk is minimal or even non-existent. The perps either think they are causing problems or they know that they are not. We should just book 'em for being f***ing stupid.

[Tony Williams]

If you want to convince me that there has bee a serious transgression, I would want some evidence that standard handheld lazers (or what ever the kids were using) has been shown to be capable of disabling/severely distracting, when pointed at an object several hundred meters away moving at 80+ miles per hour.
"However, as I have already posted, there was a practical demonstration in a news clip of the effect of one of these cheap, hand-held lasers aimed from the ground at an aircraft passing overhead. The beam merely flashed across the camera lens for a moment, but all that could be seen at that instant was a brilliant flare of green light. I can well believe that a pilot hit in the eyes by such a beam, even for an instant, would have his vision impaired for a few seconds."

Is that not enough for you? Or do you want to see a plane crash before you'll be convinced that there's a genuine risk


Further I think we need to factor in the fact that there is a co-pilot, and multipile automatic controls to prevent crashing. You have got to be kidding. Planes do not land automatically but under manual control. And we are talking about the last few seconds of flight before landing. And suppose the pilot says to the co-pilot "what's that flickering light?" so they're both looking just when the full beam sweeps over them.

I can just hear the defence in court: "My client believed that it was perfectly OK to dazzle the pilot - the crash was the co-pilot's fault for looking in the same direction."

[Harryprice]

I believe when pilots are flying (and landing) at night they have the cabin lights off to preserve night vision. A quick bright flash from a laser might destroy the night vision of both pilot and co-pilot. It can take 30 minutes to fully restore. Bit too late if you're landing at the time ...

[skbuncks]

A quick scout around ebay* shows that the green lasers available for around $5 (or around £10 in the UK) are advertised as:


Output Type :Fixed focus, continuous output and working time of over 5,000 hours
Dimension :14 x 160mm
Output power: 5mW (Class IIIb)
Wavelenth: 532nm
Works with 2 AAA battery (not included)
Body material: Metal
Body color: Black & Siliver


The use of Roman numerals in the power output classification signifies it is rated against the American Classification Standard. In the UK they would be Class 3R.
A guide on the classification is here. (http://www.hpa.org.uk/web/HPAweb&HPAwebStandard/HPAweb_C/1195733794576)

Class 3R lasers are higher powered devices than Class 1 and Class 2 and may have a maximum output power of 5 mW or 5 times the Accessible Emission Limit (AEL) for a Class 1 product. The laser beams from these products exceed the maximum permissible exposure for accidental viewing and can potentially cause eye injuries. Furthermore as green lasers are 30 times brighter to the human eye than red lasers at the same radiant power the beam can at times be clearly visible.
There are numerous examples of 5mW green lasers available over the net and plenty of anecdotes of them being used for astronomical purposes...


Perfect for teaching Astronomy to Cub and Boy Scouts. Product worked exactly as advertised and had 4mw output, which is within the acceptable range. If you want a true 5mw output pointer, you need to get the more expensive hand selected ones, but that is overkill. http://www.5mwgreenlaserpointers.com/

...if anecdotes and youtube clips are to believed ::) then I see no reason why a cheap $5 5mW green laser pointer couldn't be used to dazzle pilots.


skb

* ebay search term '5 mW 532nm Green Beam Laser Pointer Pen'.

[Legaleagle]

Further I think we need to factor in the fact that there is a co-pilot, and multipile automatic controls to prevent crashing.

Only in a commercial aircraft.

What about the private pilot, in a light aircraft, who might have some passengers on board, who's 50-100 feet off the ground on final approach, into the sunset, straining every occular muscle to focus on the runway centreline. Suddenly someone on or near the fringe of the runway shines a laser pen direct into the pilot's eyes. I would not want to be in that position. Although a crash is unlikely, the potential is there.

I personally think of it as being of the same kind of magnitude of offence as throwing stones at trains. It may be that it is unlikely to cause an accident but it's a bloody stupid thing to do anyway.

[Harryprice]

... into the sunset, straining every occular muscle to focus on the runway centreline. Suddenly someone on or near the fringe of the runway shines a laser pen direct into the pilot's eyes ...

Do you write novels in your spare time?

[Matt]

Another thought just occurred to me:

What's so special about lasers?

Laser light is highly collimated. This increases the range at which their light can be harmful.

Laser Light is of a single spatially coherrent wavelength. This coherrence may lead to constructive interference within the eye.

That all the power of the light is concentrated at one frequency may mean that parts of the retina sensitive to that frequency may be damaged before the blink reflex (which depends upon the total power across the visible range)

By analogy suppose I didn't want a cake to be squished so I placed it upon a set of scales wired to an alarm. If the scales felt a weight large enough to squish the cake it woudl sound an alarm however smaller weights would be allowed for some reason. There woudl therefore be wieghts that if spread across the full surface fo teh cake woudl not soudn the alarm but if focussed upon a knife point woudl indeed damage the cake. That's how our eyes defences are wired up.

The effects of laser on piots are real and documented

Here we go http://www.ntsb.gov/recs/letters/1997/A97_13_15.pdf

Accurate aiming is only a problem for someone making a targetted attack. The risks to pilots are only mittigated by a low hit rate if this rate isn't compensated for by a large number of opportunities for accidental contact.

We consider that being hit by lightning is a rare occurence. But there are so many lightning storms and so many people that even with the low probability of any particular individual being hit it stall happens to an average of half a dozen people a day.

[Legaleagle]

Do you write novels in your spare time?

Yes!

[Cuddles]

I'm not denying that it's theoretically possible to aim a sufficiently powerful laser at a pilot's eye and cause temporary dazzling. I am sceptical that it has every actually happened as a consequence of a cheap hand-held laser pointer, the kind they said could be bought for around $5.

Note the heading of the thread. I will say it again, that I fully understand that lasers are potentially dangerous things. I even know that defence companies have been attempting to build blinding weapons from lasers, however the title of the article I was responding to was "Cheap laser pointers from eBay used to blind aircraft pilots".

I have no idea what point you are trying to make here. That's exactly the kind of laser we're talking about.

Edit: In addition to skbunks' post referring specifically to things found on eBay, a few seconds with Google will turn up plenty of websites where you can buy pointers with as much power as 300mW, powerful enough to melt plastic, burn things and cause eye damage just from reflections, let alone the main beam. Of course, these are a little more expensive than $5, but it's not particularly expensive to get something as powerful as 100mW.


This is my other problem:

We all know that a prolonged direct hit to the eye can cause dazzling or even permanent damage.

What we should all know is that an extremely short direct hit to the eye will certainly cause dazzling. Again, I will ask if no-one has ever reflected light off a watch or something into your eye? This is something that's so common it's even featured in things like Futurama. Given how much more powerful a laser is likely to be than something like that, how can you possibly question whether it would dazzle someone, regardless of any permanent damage?


And let's not forget: We are trying to target a moving object. The only position from where this would be an 'easy' hit would be if you were directly in it's flight path: For example, if you were standing just beyond the runway and shining a laser as the plane was coming in to land.

Yes, that's exactly what these people do. I'm not sure why you would consider that a problem.


Note once again that I'm not denying that it would be distracting or worrying.

So what on Earth are you complaining about? The whole point is that it is dangerous because it causes problems for pilots. If you agree that it's distracting, why are you arguing?


At school (more than 20 years ago) the physics department had acquired a number of red lasers. At source the beam diameter seemed to be less than 1mm, however by 15 metres the lasers projected a thin line of length .75cm to 4cm on the wall. I guess it was due to optical flaws in the source's lens. I've noticed that most cheap semiconductor lenses have some degree of divergence due to optical flaws at the interface between the laser and the air.

Again I have to wonder what your point is? You initially claimed that the beam would be so small at a distance of hundreds of metres that only a small part of the retina would be affected, yet you once again contradict that claim by pointing out that the beams diverge to a much larger size than an eye within a few metres.


I do not think the above is ever likely to be the case when the laser-operator is outside an airport perimeter and using a cheap hand-held battery-operated laser pointer and the target is a plane in motion.

Unfortunately, what you think appears to be based solely on ignorance, both on the availability of these lasers and the effects of shining one in someone's eye. Perhaps you should try doing some basic research before making claims?

[salimfadhley]

It's more serious than that. First of all, a "sufficiently powerful laser" at "sufficiently close range" can cause permanent blindness instantly, and I recall reading that it has done so in laboratory accidents. Laser weapons have been developed to do just that, see page three of this: http://www.allbusiness.com/specialty.../492548-1.html

There are lasers which can unload megajoules of energy in femtoseconds. These devices can vaporize pretty much anything in literally an instant. I know there are also hand-held battlefield lasers (mainly used as sights for pistols) which would almost certainly blind at any range, and definitely scare the bejesus out of anybody unfortunate enough to come within it's range.


You have got to be kidding. Planes do not land automatically but under manual control. And we are talking about the last few seconds of flight before landing. And suppose the pilot says to the co-pilot "what's that flickering light?" so they're both looking just when the full beam sweeps over them.


So what on Earth are you complaining about? The whole point is that it is dangerous because it causes problems for pilots. If you agree that it's distracting, why are you arguing?

My belief is that lasers can be dangerous to air travel (and almost any other kind of travel) because they are visible from a great distance (relative to other forms of light) and therefore more likely to distract or cause a nuisance. My issue was with the claims are reported in the original links: Specifically that the cheapest handheld lasers could cause actual blindness. It was that specific claim that caused even the lowest grade of pointers to be banned in Australia.


Again I have to wonder what your point is? You initially claimed that the beam would be so small at a distance of hundreds of metres that only a small part of the retina would be affected, yet you once again contradict that claim by pointing out that the beams diverge to a much larger size than an eye within a few metres.

No, you misread my previous point: I was explaining that all the cheap lasers I've ever seen show a measurable beam divergence over short distances (e.g. 15m), hence the effects of an instantaneous direct hit tends to decrease with distance more than you might expect. As the beam spreads it makes it easier to get a hit, but the power per unit-area is less, so it's less likely to actually damage or dazzle.

Matt:


That all the power of the light is concentrated at one frequency may mean that parts of the retina sensitive to that frequency may be damaged before the blink reflex (which depends upon the total power across the visible range)

I remember reading that some of the most dangerous kinds of lasers operate in frequencies which are invisible to the human eye. UV lasers are valued for their ability to rapidly cauterize flesh. I believe that older laser printers used infra-red lasers. These are particularly dangerous at close range since it may take some time and considerable exposure before the victim notices that their eyes have been permanently damaged.


We consider that being hit by lightning is a rare occurence. But there are so many lightning storms and so many people that even with the low probability of any particular individual being hit it stall happens to an average of half a dozen people a day.

I have actually been struck by lightning. I was 15 years old and climbing the Breckon Beacons wearing a steel-framed rucksack. Three people in the group I was travelling with received injuries, including myself. One required CPR but made a full recovery. I got away with burns. Amongst my belongings were a small calor gas cylinder which exploded (but bizarrely did not detonate). My rucksack was torn to shreds as were the denim jeans I wore. I spent the next 3 weeks in a Welsh burns unit. I will gladly provide extensive details of the above to anybody who attends a London #SITP event. :-)


I personally think of it as being of the same kind of magnitude of offence as throwing stones at trains. It may be that it is unlikely to cause an accident but it's a bloody stupid thing to do anyway.

I agree with this.

Tony:


Is that not enough for you? Or do you want to see a plane crash before you'll be convinced that there's a genuine risk

No, however if there were plenty of aviation authority reports that laser pointers caused actual blinding due to a direct hit to the pupil I'd be convinced. With help from pilots I've found credible reports can cause distraction (because of the visible beams).


Now jumping down the throat of some teenagers looking for kicks based on what the military have produced and might become available to terrorists, looks like an example of bullying those you can because of generic unfocused fear.

Pebble, I agree with this. The journalists have an interest to sex up the article, so they take a nugget of fact and then embellish it beyond what is credible. In this case the original article combines two classic fear-factors: The mention of eBay (fear of the scary internet), and the mention of lasers (vaguely complicated sciency things). It reminded me of panic stories about "facebook stalkers" which usually fail to mention that there were stalkers long before the Internet.

[Tony Williams]

No, however if there were plenty of aviation authority reports that laser pointers caused actual blinding due to a direct hit to the pupil I'd be convinced. With help from pilots I've found credible reports can cause distraction (because of the visible beams).

You seem to be posing a false choice between the two extremes of "blindness" (implying permanent major eye damage) and "distraction (because of the visible beams)". The truth seems to be somewhere in between: a dazzling effect which can affect the pilot's vision for a few seconds, especially at night, and at a crucial moment. That is a serious matter, and deserves to be treated as such.

[Cuddles]

My issue was with the claims are reported in the original links: Specifically that the cheapest handheld lasers could cause actual blindness. It was that specific claim that caused even the lowest grade of pointers to be banned in Australia.

Then it appears that your understanding is at fault. The article you linked made no claim about permanent blinding, it said "the beam can light-up the cockpit and blind the pilot with a dazzling flash". Which is obviously true. Again, I will point out the example of reflecting light off a watch into someone's eye. That can easily dazzle them and make them unable to see or concentrate properly, why do you think a laser pointer would be so much less effective?


No, however if there were plenty of aviation authority reports

The article you linked in the OP refers to hundreds of aviation authority reports, and explicitly quotes the pilots themselves saying how bad the effects were. Did you even bother to read it before complaining here?

[tolman]

A laser pointer, even a stronger green one of 30/50/100mW energy output isn't going to light up the cockpit of an aircraft like it was daytime, but could potentially put a reasonable amount of light in there.

The subjective brightness of a 100mW the beam is going to be of the same order as a white light of ~300mW energy, which in turn equates to a average decent LED torch at something like a 1Watt/100lumen output*, though if the beam has spread wider then the window, not all the output will get inside.
If the cockpit was otherwise dark, you probably wouldn't want someone in there playing with any kind of unnecessary light, though in daytime, any cockpit lighting effects would seem to be negligible.

When it comes to being dazzled, presumably that's a combination of relatively low-level general glare from light scattering off the windscreen and the very bright point that comes from looking into the beam itself.
While that latter effect might only dazzle a small area of the retina, if it's the important bit in the middle (such as if someone instinctively looks towards the beam), that can make it very hard doing things like reading text, and even if someone looks away, if they're trying to land at the time they can't easily do that while looking at their feet.

It would certainly be interesting knowing just how good any of the cheap lasers were at sustaining a tight beam.
It'd also be interesting to know what the temporary effects were of a beam that wasn't actually bright enough to cause permanent damage. My own experience doesn't go beyond frequent short-term dazzling from regular hiigh-power LEDs while aligning them in optics and generally experimenting, and they're obviously much less of a point source, normally being at least 1mmx1mm

(* green light of a given power is roughly 3x 'brighter' than an equivalent amount of white light, and good modern LEDs operate at something like 30% efficiency)

[Harryprice]

While that latter effect might only dazzle a small area of the retina, if it's the important bit in the middle (such as if someone instinctively looks towards the beam), that can make it very hard doing things like reading text, and even if someone looks away, if they're trying to land at the time they can't easily do that while looking at their feet.

You're talking about the fovea. But won't saccades make hitting the fovea incredibly unlikely? In the interests of science I deliberately dazzled myself just now. Though I had an after-image, I could still read OK so the fovea couldn't have been hit. For night vision, the fovea is actually a blind spot because its densely packed cones are useless (the best views of an object in low light are a few degrees off centre). A brief bright flash (like a flash photo being taken) can certainly mess up night vision for several minutes - I think that is more of a concern.

[tolman]

Why bother with all that dangerous mucking about with easily discovered explosives when all you need t do is shine a light at an aircraft and watch it tumble helplessly from the sky? If that were true then the military would never bother with conventional anti-aircraft weapons.
That'd be a rather dumb way to attack military aircraft, since some have laser countermeasures, designed in the first instance to defend against laser-sighted weapons.
If anything, the military might quite like to have some of the 'bad guys' waving laser pointers in their direction.

As for enforcement against reguar civilians playing with lasers, it may well be that the current reaction is being a bit cautious, but then that's presumably what most people would want when it comes to aircraft.

There's no obvious reason for people to play with lasers that way, so if there's even a minimal risk of distraction, it seems worth stamping out where possible. If people aren't allowed to talk to a bus driver because it might distract them, having flickering light over a windshield of an aircraft trying to land probably counts as rather more distracting.

If someone really wanted to see if they could hit a plane with their laser toy, if they had more than a handful of brain cells, they could always try pointing it at a plane that's flying away from them.

[Pebble]

If someone really wanted to see if they could hit a plane with their laser toy, if they had more than a handful of brain cells, they could always try pointing it at a plane that's flying away from them.

Never been a teenage boy? That would be no fun at all, risk is the point not skill. Immortality is not just something that teenagers possess, it applies to those they interact with as well. For some this belief persists even after hurting themselves or others quite badly.

[tolman]

Never been a teenage boy? That would be no fun at all, risk is the point not skill.
IIRC, the risky things I did were generally ones where only I was likely to get hurt.

[Montag]

Wow my first post!!

Happened late last year.

http://www.thisisplymouth.co.uk/news/Laser-light-directed-police-copter/article-1629129-detail/article.html

Being very simplistic and a Physics teacher:

I use lasers in class and I have to say some of the newer cheapo lasers are very bright and focussed. When calculating the wavelength of light using a grating the kids have been getting better results than the desk top laser. We bought a class set of pointers and the focus is generally much tighter over a classroom length.

I've been flashed and have found it painfull and leaves an after image.

The green lasers we use are brighter.

I would agree that a quick flash from any of these bad boys would not 'blind' you but I could see it definitely dazzling you enough to cause an accident. A plane on approach at night and the pilot loosing all night vision... I suppose the question is: would you like to risk being in the plane when that happened?

Couldn't see it happening to a military plane or big jet but on a small single pilot 4 seater? Plausible I'd say

[Tony Williams]

I think that part of the problem in this thread is that the word "blind" has more than one meaning. While it means permanent loss of vision, it is also used popularly to mean temporary loss of vision, as in "I was blinded by the car's headlights".

The shining of cheap but powerful green lasers at aircraft pilots won't cause the first meaning, but it can certainly cause the second.

[salimfadhley]

Yeah, I think you have to take "blinding" very non-literally: It's phenomenally unlikely that a handheld low-power laser pointer could cause literal permanent or medium term blinding.

On the other hand, I've now seen very compelling evidence that even very low power devices are visible from aircraft, and that they are very distracting. This distraction might render a pilot "blind" to hazards. So the threat is very real, it's just been reported in a somewhat sensational way by the press.

[Graham Lappin]

I'd love to see myth busters have a go at this one

[Croydon Bob]

I'd love to see myth busters have a go at this one

I'd love to see how they could rig Buster up to do a test.

[skbuncks]

Heard an update on this on the radio this morning so thought I would share...


There have already been a total of 761 recorded instances of lasers being shone at pilots so far this year, surpassing last year's total of 739 cases...Offenders can now be charged with 'shining a light at an aircraft in flight so as to dazzle the pilot,'..."You could be sent to prison, or you could get a fine of up to £2000."
http://www.bbc.co.uk/newsbeat/11280230

skb