

The US crackdown on not-so-harmless laser strikes - sbochins
http://arstechnica.com/tech-policy/2014/05/blinding-light-the-us-crackdown-on-not-so-harmless-laser-strikes/

======
BrandonMarc
I'll agree that firing lasers at aircraft is dangerous ... for the pilot, and
anyone in that aircraft's vicinity since it needs its pilot to fly properly.
Makes total sense.

But ... it's hard to square that with articles like this one:

[http://www.bbc.co.uk/news/blogs-magazine-
monitor-23178484](http://www.bbc.co.uk/news/blogs-magazine-monitor-23178484)

Look at those pictures. Wow. Then you find out _why_ the crowd was using the
lasers ...

During the protests in Egypt, there came a point where there would be tens of
thousands of people crowded into Tahrir Square, with military helicopters
buzzing overhead.

Those helicopters would look like a rave party, thanks to darn near everybody
in the crowd below firing lasers at them.

Initially journalists assumed it was to mess with the pilots, but after
speaking to people on the ground the reporters discovered the protesters were
very happy with the Army for trying to prevent Morsi's replacement from
overstepping his authority.

That's right, they were firing lasers at the helicopters as a sign of
solidarity, because they liked the pilots, and wanted to encourage them.

Given the topic of this thread, that activity seems utterly ridiculous (and,
of course, dangerous). But I remember reading interviews with some of the
pilots, and they didn't seem to mind.

Like I said, I figure firing lasers at pilots is not just a harmless prank ...
but articles like that one sure cause a lot of cognitive dissonance with that
perception.

~~~
BrandonMarc
Ah, now I understand. As mentioned in another comment, military pilots wear
helmets with visors specially designed to deal with bright lights.

Life-flight helicopters, or hospital choppers transferring kids getting
transplants, likely don't have such equipment.

------
vl
How do we know that these concerns over $3 laser pointers and pilot taking
"day off due to headache" are horseshit?

Simple. If it would be true all military aircrafts, ships and vehichles would
have high-power lasers installed to blind enemy pilots and drivers and all
guerrilla fighters would have pockets full of $3 chinese laser pointers to do
the same. If it would be possible to disable a pilot for a many hours like
this, no military aircraft would be ever able to approach any densely
populated area. Dishonest horseshit.

Also from other comment:
[https://www.youtube.com/watch?v=S92XUsfI5ng](https://www.youtube.com/watch?v=S92XUsfI5ng)
How are they flying at all if this is true?

~~~
snom380
And such weapons exist. And military pilots were helmets that protects against
sunlight _and_ bright light. If lightning is anticipated, one of the pilots of
an airliner will usually wear sunglasses to protect the night vision.

And it's a matter of eliminating contributing factors to accidents. Pilots
have downed airplanes because of a malfunctioning pitot tube or fuel indicator
light distracting them. People that don't get the laser pointer problem don't
really understand why flying is so safe nowadays.

~~~
Zancarius
> Pilots have downed airplanes because of a malfunctioning pitot tube or fuel
> indicator light distracting them.

To be fair, a malfunctioning pitot tube is a class of _equipment failure_ that
has had disastrous consequences, so I wouldn't put it in the same category as
a distraction. Distraction is usually considered pilot error (or a fault of
the design) as in Eastern Air 401 where the pilots were so focused on the
landing gear light that they failed to notice one of them had disconnected the
autopilot (due in part to a design issue).

I really don't mean to nitpick, but equipment failures are most definitely not
analogous in this case. Mostly because you can do many things to reduce the
likelihood of equipment failure, but distraction is very nearly impossible to
eliminate.

~~~
snom380
I agree about equipment failure, I used those examples to point out that just
because something has occurred several times before doesn't mean you can
discount it as a potential contributing factor. A better example is the
sterile cockpit rule. You can never eliminate distractions, but you can work
on reducing them (though in a worst case scenario I believe that laser flashes
can be more than just distractions).

------
briandh
> I would not call it [the 14-year sentence] harsh. I would say it is a
> penalty that fits the crime, but I believe that it will have a deterrent
> effect, and I hope it will.

That she does not see sending a father of two young children to prison for
this as "harsh" is quite frightening.

edit: typo

~~~
marme
the article is misleading. He got arrested for pointing a laser at the
aircraft but he got 14 years for committing an act that violated his parole.
He most likely had 14 years left on his sentence when he was paroled, probably
drug charges, and since he violated his parole he was sentenced to finish
those 14 years. The girl probably got a fine and some probation which is what
the guy would have gotten if it was not for him being on parole

~~~
briandh
I forgot about that, but even so, I find it excessive. Especially if you are
right and it was merely drugs.

The only way I can envision it being justified is if his previous offense was
violent or otherwise straightforwardly antisocial, with this laser-pointing
being part of a pattern of malicious behavior.

------
Lerc
Have there been any recorded instances of actual harm due to laser strikes? I
have encountered many anecdotes of annoyance and inconvenience but nothing
tangible. At 9.5 instances per day there should be a reasonable amount of data
to indicate the range of harm.

~~~
wyager
> there should be a reasonable amount of data to indicate the range of harm.

There is. And the obvious conclusion is that the harm is completely
negligible.

There is absolutely no possibility of physiological damage from light exposure
(some people still seem to be kicking that idea around), and the chance of
causing the pilot to be unable to operate the aircraft due to distraction or
damaging night vision is very low.

~~~
snom380
If you are so certain of that, I have an experiment I would like to test with
you. One includes you looking into one of these lasers that can light
cigarettes.

Next up I will give you basic landing training and you get to land a small
aircraft at night all by yourself with a laser pointed at the cockpit. You are
of course allowed to use the remaining eye.

------
jliechti1
Here's a video of what a laser looks like from a helicopter pilots
perspective. It's a lot more powerful than you think it might be.

[https://www.youtube.com/watch?v=iI7Qq1mYQlI](https://www.youtube.com/watch?v=iI7Qq1mYQlI)

~~~
GrinningFool
I hate to say it, but... that's _it_?

I could see it causing serious problems if someone hit the copter and held it
at exactly the right position for it to cause continued glare. But that brief
flash? maybe it loses something in video, but it seems less intense and far
more transient than oncoming traffic w/ highbeams on a dark road .

~~~
cdash
Nothing is lost in the video as someone else has already commented on in this
thread, CCDs are actually more sensitive than the human eye to lasers.

~~~
gnaffle
That's not really true at night though, CCD cameras can change their light
sensitivity quickly, something human eyes can't do (after a bright flash,
you'll lose your night vision up to several minutes).

------
GrinningFool
On the last page of the article we have this in the form of expert testimony:
"You also have scattering occur which can affect vision performance when you
hit like optometric lenses, like glasses, or if it goes into the eye, if you
have any cataract or opacities in the lens or in the cornea of the eye itself,
which can result in vision performance loss.”

Correct me if I'm wrong (and I may be), but ... don't you pretty much need
perfect vision to fly[1]? And if so, how is the quoted testimony relevant to
this _specific_ case?

I accept that it's potentially dangerous and that it should be further
studied. But by the pilots' descriptions no more so than oncoming traffic on a
dark street. In addition, the only information we had about after effects was
anecdotal and seemed to consist of a couple of pilots reporting migraines and
tingling.

I don't know - when you're throwing someone in jail from 2-14 years, I just
think there should be more than a couple of anecdotes to support threat of the
action that got you there.

1\. after reading further comments, looks like my assumption here is wrong -
it's possible to fly with these conditions, presumably vision must be
_correctable_ to perfect?

~~~
ldarcyftw
>don't you pretty much need perfect vision to fly

Army helicopter pilots remain on flight status with vision sharpness as low as
20/400.

[http://usmilitary.about.com/od/armytrng/ss/rotarypilot_5.htm](http://usmilitary.about.com/od/armytrng/ss/rotarypilot_5.htm)

"20/400 vision is considered severe visual impairment just shy of blindness."

~~~
GrinningFool
Yep - see my [1] edit from yesterday, could be you had a stale page :)

------
signa11
fta: Federal criminal charges were brought against both of them in March 2013,
with a three-day trial concluding in December 2013. Despite his lawyer's best
efforts, in March 2014, Rodriguez was sentenced to 14 years in prison.

wow !

~~~
geetee
That's horribly excessive, even with him being on probation. I imagine most
people are not aware of how dangerous it is.

~~~
cdash
Probably because there has been no evidence it is very dangerous and there
would be evidence if it actually were.

~~~
res0nat0r
Besides all of the pilots...you know...saying it is dangerous.

------
dfc

      > the severity of the strike depends significantly on how the laser
      > hits the helicopter...If the strike comes from the rear, it’s less
      > of an issue.
    

This may be a stupid question but how do you "laser strike" a pilot from the
rear of the aircraft? I can understand how this happens with an Erickson Sky
Crane when the pilot is in the aft facing seat.[^1] With a traditional
helicopter it seems like there is a lot of stuff
(helicopter/helmet/headphones) blocking any strikes from the rear.

[^1]: [http://www.flyingmag.com/aircraft/helicopters/erickson-
air-c...](http://www.flyingmag.com/aircraft/helicopters/erickson-air-crane-
back-seat-driving)

ADDENDUM: I had no idea this was weaponized and had been deployed as early as
the Falklands:
[https://en.wikipedia.org/wiki/Dazzler_%28weapon%29#First_use...](https://en.wikipedia.org/wiki/Dazzler_%28weapon%29#First_use_in_Falklands)

~~~
jleader
I imagine that's their point, a strike from the rear is less likely to blind
the pilot, but it's not impossible. There's a lot of glass, and lots of other
polished glossy surfaces around an airplane, so a laser beam could still
conceivably reflect off a surface in the pilot's field of view.

------
wyager
Much of the panic about lasers is completely unwarranted.

You can just do the math yourself to prove that most of the panicked news we
hear is bullshit.

For any given laser, we know the divergence (the given figures are usually
smaller than the actual divergence). Let's look at the wicked lasers arctic, a
popular (but low quality) 445nm blue laser with a power output of up to
2000mW. This is one of the more powerful consumer handheld lasers out there.

Wicked claims a divergence of 1.5mRad. I think that's optimistic. It's
probably really above 2 mRad.

Let's say you get within 300 meters of a plane. That's pretty tricky; you'd be
lucky to do that even near an airport (and the closer you are to an airport,
the easier it is to get arrested.

At 300 meters, the beam is (very optimistically) about 450mm. Because of the
multimode properties of the 445nm diode, even with this very optimistic spec,
it's probably more like a 1m x .45m ellipse. But let's just assume a circle.

pi _.45_.45 = .63 meters squared.

That's a power density of 2W/.63m^2, or about .00037W/cm^2.

According to the IEC and SPIE, that's a low enough power density that at
visible wavelengths, you could be exposed to it for long periods with no eye
damage. [1][2]

This is assuming ideal conditions, including a perfect beam, no atmospheric
interference, and no reflection/filtering on the aircraft.

There is no physical danger to the pilot; the risk is that the pilot gets
distracted. This risk is not substantial, as it's very difficult to keep a
laser trained at a pilot long enough to be dangerously distracting, and you
have to be very close for the laser light to even be noticeable.

By the way; There are a few videos floating around of lasers shining into
cockpits. Most of these look really bad, because A)they filmed with the
intention of making lasers look dangerous and B)lasers saturate camera CCDs
very easily, so they can look incredibly bright on video even if our eyes
handle them pretty well.

[1]
[http://en.wikipedia.org/wiki/File:IEC60825_MPE_W_s.png](http://en.wikipedia.org/wiki/File:IEC60825_MPE_W_s.png)
[2]
[http://spie.org/Documents/Publications/00%20STEP%20Module%20...](http://spie.org/Documents/Publications/00%20STEP%20Module%2002.pdf)

~~~
sokoloff
Pilots take a lot of precautions to preserve their night vision (the red map
lights aren't just for Hollywood dramatic effect).

I appreciate you doing the math on energy and luminous flux density
(seriously), but the concern is beyond distraction.

I was hit at 2500 feet near Portland a few years back and it illuminated my
left wing first (high wing), causing me to close one eye but the night vision
in the open eye was seriously hampered for >5 minutes and even the eye that I
quickly closed was modestly affected for a short time. I don't recall the
height above terrain that 2500 MSL represented there, but I have to think it
was better than 2000' distance, and that was over a populated (read: lit)
area. In a darker environment, a laser's effect on night vision would be more
pronounced.

~~~
wyager
> the night vision in the open eye was seriously hampered for >5 minutes

That seems like a very drastic effect from diffuse exposure to laser light at
long distance.

Partial adaptation from full sunlight to darkness takes about 5 minutes [1],
and the diffuse laser light you were exposed to is orders of magnitude weaker
than sunlight.

I would be curious to see some more experimental research in this area. We
know a lot about energy thresholds for eye damage, but we don't have as much
precise data for adaptation thresholds.

[1][http://en.wikipedia.org/wiki/Adaptation_(eye)](http://en.wikipedia.org/wiki/Adaptation_\(eye\))

~~~
hollerith
>the diffuse laser light you were exposed to is orders of magnitude weaker
than sunlight.

Sure, but the pupils would be much more open than they would be in sunlight.

~~~
discardorama
> but the pupils would be much more open than they would be in sunlight.

That is the crux of the problem. In sunlight, your pupils are so constricted
that negligible light hits the retina. But at night, they're fully dilated and
a sudden burst of laser can cause harm.

------
gnaffle
I find it interesting how many people here discount the risks of laser
pointers, and trivialize the stories of pilots. The very same people probably
encounter the same attitude from customers and others in their work in the IT
industry, for instance with regards to security measures ("why can't we just
run our customer database on a publically reachable IP, it saves so much
trouble, and I know a guy that has done it for years and never had a
problem!").

------
spiritplumber
[http://igg.me/at/minilaser/](http://igg.me/at/minilaser/) Shameless plug for
my laser cutter.

Pewpew responsibly, please!

------
trhway
i'd say a must read for this discussion

[http://en.wikipedia.org/wiki/Laser_safety#Old_system](http://en.wikipedia.org/wiki/Laser_safety#Old_system)

"Class I

Inherently safe; no possibility of eye damage. This can be either because of a
low output power (in which case eye damage is impossible even after hours of
exposure), or due to an enclosure preventing user access to the laser beam
during normal operation, such as in CD players or laser printers.

Class II

The blink reflex of the human eye (aversion response) will prevent eye damage,
unless the person deliberately stares into the beam for an extended period.
Output power may be up to 1 mW. This class includes only lasers that emit
visible light. Most laser pointers are in this category.

Class IIa

A region in the low-power end of Class II where the laser requires in excess
of 1,000 seconds of continuous viewing to produce a burn to the retina.
Commercial laser scanners are in this subclass."

------
negativity
I'm not buying into the sensationalized panic over laser pointers and planes.

If modern air traffic isn't robust enough to tolerate random citizens
flickering laser pointers at flying objects then they don't deserve to be
flying.

~~~
morbius
You haven't even read the article, have you?

~~~
negativity
I did read the article, and it seems like a situation totally blown out of
proportion.

    
    
      Since the FBI began keeping track in 2005, there have been 
      more than 17,000 laser strikes in total—more than a fifth 
      (3,960) in 2013 alone. During the first three months of 
      2014, the FBI reported an average of 9.5 documented 
      incidents every single day.
    

Those are absurd numbers. To me, that alone immediately reads as: We have
airplanes in the sky that can be tampered with far too easily.

Technological arms races are a recurring phenomenon as technology contues to
evolve. This is a particularly interesting one. Think about what a massive
technological upset this could be, if laser pointers are honestly so
indomitable.

Planes and pilots are going to have to change, and it's going to be expensive
and frustrating. And believe me, the last thing I want to see happen is for
all manned aircraft to be grounded and replaced with drones.

But reading the whole article, it's obvious to me that law enforcement is
fighting a losing battle, and that's a bad thing, because then what you get
are fishing expeditions, witch hunts, emotionally charged propaganda and harsh
penalties to make examples of people.

