White Vans, Laser Beams, and Xmas Lights

Living through the 2002 Beltway Sniper episode taught me that mass psychosis is only a few sloppy news reports away. Millions of people lived in mortal fear of white panel vans despite the lack of any real evidence linking the ubiquitous vehicles to the shootings.

With the laser beam "attacks" on airliners I fear we are headed down the same irrational path. First, there is the fact such an attack would be incredibly difficult to pull off. Your target would be thousands of feet in the air, traveling at hundreds of miles an hour, in the dark, and you are aiming for a spot perhaps a couple feet square. Use the Force, Luke, and good luck. And yet this has happened a half dozen times in the past few days?

How about a much more likely cause of pilot encounters with strange lights on the ground in recent weeks, one that even has a sure case history behind it. The FAA blamed a Christmas flood light on a house in Hawaii for distracting pilots trying to land at a nearby airport. The feds contacted the homeowner and had the light put out.

Did the FBI bother to talk to anyone at the FAA about the laser beam theory? Does the FBI even know it is the Christmas season?

Comments

[thoreau]

Last night on one of those cable news shows (can't recall which one) a pilot was interviewed and said that these sorts of attacks would require a very sophisticated piece of tracking equipment in order to shine a laser beam in a pilot's eyes for several seconds.

He failed to point out that the power requirements would be considerable: It doesn't actually take all that much power to blind the pilot, but if the beam is spread out over the area of the cockpit window (a necessity unless they have REALLY good tracking devices) then it will have to be quite powerful (a lot of energy spread out has the same intensity as a little bit of energy concentrated). My initial estimate is a few watts of energy. A laser operating at a few watts requires a lot of power and cooling water. That would require a cargo van. I think a few Middle Eastern guys in a cargo van parked near the airport, watching the planes and pointing funny equipment at them, would have attracted some attention.

Also, this would be quite an investment for a terrorist group. Surely there must be cheaper (and more effective) ways for them to create havoc.

Call me skeptical.

[Ruthless]

Journalists are being accurate in the sense that they convey the panic and hysteria that grips us all as a species.

Speaking of the season, I was just thinking the holiday just past is when children's eyes glow. Tonite is when adults'...

[Roswell]

These are obviously beams from alien spacecraft.

[D Anghelone]

Millions of people lived in mortal fear of white panel vans despite the lack of any real evidence linking the ubiquitous vehicles to the shootings.

Hyperbolic.

Your target would be thousands of feet in the air, traveling at hundreds of miles an hour...

On their landing runs, airplanes are not at thousands of feet or at hundreds of MPH.

[Jay Kominek]

They might not be at high altitudes, or moving a fast as they can, but they're still coming along at a fair clip.

How much luck do cops ever have trying to shoot cars? Not much, AFAIK. With a laser, you've got to not just get the pilot in the face, but hold it there for at least a few seconds, while the plane goes through turbulence, etc.

Anyways, laser-protective eyewear is a few hundred dollars at worst. The airlines can spring for a pair in every jet's cabin if there is any genuine threat. The co-pilot can pop them on during take off and after landing, and take over if the pilot can't see.

But really, I expect about as much will come of this as has the threat of terrorists using .50-cal rifles on passenger planes.

[Coarsetad]

There is a lake with a jogging trail around it at the end of the runaway of Love field in Dallas. At some points in my jogs Southwest Airlines planes would routinely fly close enough to leave a small wake on the lake and in the evenings it was easy to see people in the windows. Despite all that, these things are still hauling-ass. It would probally be possible to hit the plane with a laser, but getting a beam in a window and holding it there, would only happen out of blind-luck.

By the way, for those living in Dallas, Bachman Lake is by far the best "experience" for watching planes land, Homeland Security just asks that you leave your RPGs are home.

[D Anghelone]

How much luck do cops ever have trying to shoot cars? Not much, AFAIK. With a laser, you've got to not just get the pilot in the face, but hold it there for at least a few seconds, while the plane goes through turbulence, etc.

When working with lasers, we attended a laser safety class where we were told it takes but a fraction of a second to suffer permanent sight damage from burning. Perhaps they fudged the safety factor.

[Pro Libertate]

Aren't there handheld lasers that hold their focus much better than your standard laser pointer? I'm hopelessly ignorant on this topic (and not in the mood to do any research right now), but I understand that there are green lasers that can maintain a coherent state for something like 10,000 feet. I've never seen one, but during my recent foray into astronomy (8-inch reflector for Christmas--yeeehaw!) I've run across mention of these lasers as tools for pointing out objects in the sky. Whether the beam would stay coherent after hitting a window is the 10,000 foot question.

Of course, actually hitting the cockpit and doing any sort of damage is quite unlikely. They (meaning the "they" who do such things) could always coat the windows with something that would limit the beam's intensity, in any case. When I first heard about this, I was more concerned that someone might be attempting to target airplanes, not blind pilots. Or maybe it is a strange run of Christmas displays running amok--my brother's house could blind a shuttle astronaut.

[D Anghelone]

Coarsetad,

You describe a landing aircraft as viewed from the side. From the front, where be the pilots, there is considerably less haul.

[Coarsetad]

No you can stand in front of the planes as they approach, but line of sight into the pilots window disappears behind the nose of the plane while it is still very far away (at least a 1/2 mile or so). Not to mention the planes had a tendency to jump around quite a bite. I rarely observed a landing where the plane made an absolute beeline, and wasnt kicked around a bit, by the wind.

[Stevo Darkly]

Did the FBI bother to talk to anyone at the FAA about the laser beam theory? Does the FBI even know it is the Christmas season?

"Do they know it's Christmas time at alllll?"

[grylliade]

On their landing runs, airplanes are not at thousands of feet or at hundreds of MPH.

It's still 160-180 mph at takeoff. At landing it'll be somewhat lower, due to all the fuel expended in flight, but the plane will still probably be traveling at 150-200 mph. Now imagine pointing a laser at the cockpit of an airplane moving at 180 mph, a few hundred feet off the ground, sinking at maybe a few hundred feet a minute, and holding it there while it does all this. That's going to require some pretty heavy-duty computer tracking equipment, and as thoreau said also a lot of power and cooling equipment. This isn't the sort of thing that you could pull off with one guy holding a little laser pointer. At the very least, even assuming the tracking, cooling, etc. problems were pulled off, at present levels of technology it would require something like a rifle in size and, probably, shape. Again, you don't think that someone would notice of a bunch of Middle Eastern gentlemen were pointing "rifles" at landing airliners? Or any other gentlemen or ladies, for that matter. This is likely something else entirely, with Christmas lights being as likely as anything else.

[thoreau]

When working with lasers, we attended a laser safety class where we were told it takes but a fraction of a second to suffer permanent sight damage from burning. Perhaps they fudged the safety factor.

All depends on the wavelength and power. Not to mention the width of the beam. Unless the beam is tightly focused it would spread out quite a bit between the laser and the plane. The more it spreads out, the weaker it is.

The bottom line is that hitting a plane with a laser is fairly easy. Hitting a particular spot like the front window is much harder, especially if you are on the ground. (The best line of sight would be from a hill or tall building opposite to the line of approach.) Hitting the window and holding it would be even harder. And between the laser and the plane, realistically you'd be looking at a distance of a mile or more (probably much more). Over such a distance the beam could spread out to fill the window, but when it spreads out it becomes weaker. So you'd need a pretty powerful laser with a cooling system to avoid damaging the laser and power supply. (Well, if the terrorists want to do it more than once they need the cooling system.) Not to mention a sophisticated tracking system.

If I wanted to damage their eyes I'd use an infrared laser anyway. Sure, you can't see if you've hit it, but for that sort of accuracy you'll be relying on a computer-controlled tracking system anyway to do the aiming. Infrared is nice because they won't notice any eye damage until it's too late, and the invisible beam won't give away the terrorists' location.

The more I think about it, the more skeptical I am of this. Not only would it be very technically difficult and expensive to achieve this sort of feat, if they're going to all that trouble they might as well use infrared instead of visible light.

I understand that there are green lasers that can maintain a coherent state for something like 10,000 feet

Coherence has nothing to do with it. Coherence is a property of a wave, related to the difference between a pure tone in music vs. noise. Coherence is important in scientific applications, but it's irrelevant for this application, where all you need is a bright light to blind somebody. You're probably thinking of collimation, the property of a beam that stays tightly focused. That has more to do with the lenses employed rather than the laser itself.

[thoreau]

sAt the very least, even assuming the tracking, cooling, etc. problems were pulled off, at present levels of technology it would require something like a rifle in size and, probably, shape.

Actually, it probably wouldn't look anything like a rifle. Here's how it would probably work out:

On top of a tall hill or building located opposite the airplanes' approach path, there would be several pieces of equipment. The first would be a bigass power supply. The second would be a really noisy thing with hoses coming out of it. That would be the cooling system. Some of the hoses would run to the power supply. Other hoses would run to a big rectangular box, probably several feet in length and a 1ftx1ft width and height. That would be the laser. The laser would run to some box full of lenses and mirrors pointed at the path the planes take. That would be the aiming device. There'd also be a few big infrared cameras pointed to where the planes come in. The cameras would have very wide lenses to collect as much light as possible. There would probably be baffles around the camera to block stray infrared light from ground-based sources. The cameras would provide real-time feedback to the aiming device, to adjust the camera's aim. There'd be at least 1 laptop, probably a few more.

I take back what I said earlier: They probably wouldn't attract suspicion. They'd look like a bunch of science graduate students doing some night-time field work. And they would be doing it at night, because if they did it during the day the infrared signal of the scattered light from the plane would be drowned out by ambient IR from the sky.

(And yes, I know, the sky is mostly blue, but there's still some IR, and they'd need maximum contrast for this type of work. Besides, at night the pilots' irises would be open wider so that less time would be needed to do the damage.)

When you consider the amount of money and technical expertise needed to do this, it would be much cheaper to make some conventional explosives and attack strip malls in suburbia. That would kill at least as many people and create far more panic, for that would send the message that they can strike us anywhere in our day-to-day lives, not just when we go to high-profile targets like stadiums, airports, and skyscrapers.

[Pro Libertate]

thoreau, your first mistake was assuming that I was thinking. Actually, I used "coherence" in the lay sense, meaning that the beam stayed tight and didn't disperse. I have a laser for collimating my mirror, so that's not where I was going.

Just doing a quick Google search, here's a site that discusses the laser I'm talking about. I think it can be used for collimation, but that's not the principal purpose. They do mention that you shouldn't point the thing at an aircraft, but that may be mere puffery.

Should've gotten that PhD in physics. . . .

[Memnon]

"But really, I expect about as much will come of this as has the threat of terrorists using .50-cal rifles on passenger planes."
This is one truth if I ever saw one. Forget square feet. With a laser you have to hit both eyes( each dilated pupil 0.05 sq inch. With a machine gun you hav to hit the pilot. Witch is more feasible?

[thoreau]

I take back what I said about doing it at night. Aiming the IR laser precisely would be easier at night once the airplane is acquired, but identifying the airplane in the first place would probably be easier in daylight.

Still, the more I think about it, the more I realize that the technical sophistication required to do this is prohibitive. It's not that it couldn't be done, it's just that if a terrorist group wants to create havoc and kill Americans, there are much more efficient ways to do that.

This is even less plausible than the shoulder-mounted rocket scenario.

[D Anghelone]

You guys are missing the fact that, if these reports are true, laser beams have been reported by pilots to be sharing with them their cockpits.

thoreau,

This looks much like the laser and power supply we used. That power supply is just some plastic encased components and is easily held with finger and thumb. That laser was neatsy technology in 1970 and it could make you blind.

[thoreau]

D Anghelone-

True, a small laser can make you blind.

But if you want to blind a pilot, unless you have really really really good tracking equipment, you'll need to flood the cockpit window with light, in order to be sure that you hit his eyes. Which means you'll need a much larger beam.

If you spread out the beam from that little laser to the size of a cockpit window it would be harmless because the light would be spread out and hence be less intense. In order to deliver a large beam that's intense enough to blind you'd need thousands of times as much power as that laser can deliver.

And even with the very powerful beam you'd need good tracking equipment for anything more than momentary exposure (a fraction of a second). And unless the power is strong enough, momentary exposure won't suffice to blind.

Besides, it would make more sense to use infrared (IR) lasers rather than visible light. A Q-switched YAG would work well for that purpose, and such lasers are just as easy to obtain as visible lasers. IR lasers cause damage that the pilot won't notice right away, so the pilot won't blink or avert his eyes until it's too late. And IR lasers won't create any stray or scattered visible light that might give away the terrorists' location to investigators.

Moreover, tracking and aiming would be much easier (and less expensive) if the attacker is located on a hill or tall building that faces the path of planes landing or taking off. My own anecdotal observation is that airports are situated and flight paths are chosen to minimize the number of tall buildings and hills in the flight path. Which is not to say that there are no possible attack sites, but it is one more resource constraint facing terrorists.

Finally, the equipment and training needed to do this are expensive. If a terrorist group has the people and money in place to do this, those same resources could cause much more death and panic if deployed for more low-tech attacks.

[Bill]

thoreau,

Do you think a CO2 laser would work better?

[thoreau]

Bill-

Maybe. I don't work with CO2 lasers, but I've heard that they're used for cutting flesh. So I suppose that would work. What I don't know is the power capabilities and electrical and cooling requirements.

In any case, the other issue would be tracking. I don't know as much about that, but I imagine it would involve 2 cameras. I'd couple the laser into a system of mirrors and lenses mounted on a goniometer (basically a device that rotates on 3 axes to let you orient something however you want). I'd mount a visible-sensitive camera and telescope on the goniometer as well, and use data from the camera to adjust the goniometer so the plane stays in the center of the field of view. That would be the "rough adjustment."

For the fine adjustment, I'd use a second camera with a filter that only passes the wavelength of the laser, so I can see where the laser is hitting the airplane. I'd adjust the mirrors to center the laser beam on the cockpit window. And I'd adjust the lenses to change the beam size so that it fills the cockpit window but isn't too much larger (a larger beam means wasted light).

A weapon system like this could probably be built using mostly off-the-shelf parts, but it might take a year to develop and test. It would take several guys working together. A ballpark estimate is a half a million dollars give or take a few hundred thousand. They'd need a vehicle to haul it in, and a place to use it from. And they'd still need a place to use it from, preferably a hill or tall building opposite the flight path.

[D Anghelone]

But if you want to blind a pilot, unless you have really really really good tracking equipment...

Hell man, I'd just aim it through my AO modulator and get my Bragg angle and...

Nah, I'd just aim the damned laser. Don't really know how big a rig would be needed these days.

[Mark]

This is fun speculation. Let me try to keep it alive a little longer.

I'm not sure I believe that the tracking problem is all that hard to solve. (Which may mean I don't understand the problem.) For one thing, there may be a human solution. Before the availability of super-fast films, photographers would photograph fast moving object by turning to match their motion. There are old pictures of trains tearing across the landscape where the train is clear and the landscape is blurred. The photographer just turned to match the train. It was, to be sure, a matter of great and rare skill, but it could be done. Likewise, hunters can shoot birds out of the sky. I wouldn't be surprised if someone who grew up hunting fast-moving livestock predators could learn to aim a laser at an aircraft and hold it steady.

The high-tech route to aiming might not be all that difficult either. Military tracking systems are expensive because they have to aim at military aircraft doing military things. Unlike an attacking military aircraft, a landing commercial aircraft has no stealth features, is painted to be easy to see, doesn't jink around to thwart prediction, has no countermeasures, emits plenty of heat, is shining bright lights at the ground, and flies a very predictable path with a known end-point.

You might be able to exploit the fact that the engines and the cockpit form a triangle that doesn't change much during landing. Same with the landing lights. Or you might target and track the highlight of the laser reflected off the nose, with a higher-powered coaxial laser aimed at an offset to do the damage. Accurate motion control equipment isn't all that expensive.

There might also be ready-made solutions to the problem. Anybody know what sort of features a military laser target designator has? Perhaps one taken off some equipment the Russians lost in Afghanistan? Those things can blind people.

I find the argument that they should have used an infrared laser much more convincing. The only thing I can come up with is that you know the cockpit glass will pass visible light.

Also, the hits on the cockpit could be luck. We don't know how many hundreds of planes have been hit by lasers to produce the half-dozen or so reports we have.

[Dark, Whistler, In The]

Only one week ago, that pilot guy at Salon promised us all that this laser business is nothing more than a bunch of flapdoodle.

That settles it for me.

If you can't trust Salon, then, well, life isn't worth living, is it?

[Dark, Whistler, In The]

And white vans haven't been officially OK'd yet, have they?

They caught the snipers. But there's still white vans out there.

I've seen them driving around. You have too, even though you're too scared to report them.

[Matt]

Keep in mind that (just as with guns and bullets) there's a _big_ difference between "don't do this to yourself, as it'll hurt you" and "doing this to someone else will reliably hurt them".

Shooting a small laser into your own eye will certainly do permanent damage...but the damage probably won't be both sufficiently total and sufficiently immediate that it would be useful as a weapon in this context. The hypothetical terrorists, after all, aren't primarily looking to blind pilots...they're looking to crash airplanes, and to do that, their weapon of choice has to be relatively certain of incapacitating the pilots in less time than it takes those pilots to get on the ground. A pilot who lands successfully but is nevertheless permanently blinded in the process would count as a failure for the terrorists.

Given that, the amount of power the laser needs, the precision with which it must be aimed, and the time it needs to be kept on its precise target all go up rather dramatically.

Seriously...smuggling in a shoulder-launched missile would be easier. Much easier.

[D Anghelone]

Mark,

A better comparison would be to a movie camera as the sighting on the target is continuous and not a one-shot deal.

Comparisons to rifles are not good as a rifle would require individual shots and leading the target.

A laser is continuous and instantaneous. You needn't lead the target, there is no recoil, no recharging and no re-acquisistion of the target. You simply aim and pan to find the bullseye.

[Larry A]

>"But really, I expect about as much will come of this as has the threat of terrorists using .50-cal rifles on passenger planes."
>This is one truth if I ever saw one. Forget square feet. With a laser you have to hit both eyes( each dilated pupil 0.05 sq inch. With a machine gun you hav to hit the pilot. Witch is more feasible?

Aargh. The .50 caliber rifles being banned in California and elsewhere are semi auto or bolt action. NOT "machine guns." And they run $1,200 up to $4,000 or so.

Terrorists, of course, could ignore the civilian market and purchase a surplus .50 Cal Browning anywhere in the world.

[thoreau]

Mark-

First, keep in mind that hunters usually go for one shot, two at the most. And the second shot is usually against an animal that's slowed down after the first shot. That's different from firing a series of consecutive shots into an animal running at constant speed.

Second, the price tag that I cited isn't for the tracking. I'm willing to believe that the tracking could be done on the cheap. Especially if the terrorists are located in the flight path. (Not 100% convinced, but seems plausible.) The biggest price tag is for a high-powered laser with a portable power supply and cooling system. And I have no idea what the price tag would run there. I'm guessing a few hundred thousand, but I may very well be erring on the low side.

You do raise a good point about IR lasers and the cockpit windshield. To be confident of getting through the cockpit window, the best approach would be to use a laser with a wavelength just barely outside the visible range. If the cockpit window passes red light it will almost certainly pass near-IR. A YAG (1064 nm wavelength) would probably still work, but I'm not 100% on that. I know there are a lot of IR diode lasers between 700 nm and 1000 nm, but I don't know that they can reach the required power.

I still maintain that if a terrorist group had the money to acquire a portable high-powered laser, and the technical expertise to rig up a tracking system, they'd be better off putting those resources into conventional explosives and nerve gas.

[thoreau]

A belated response to a question posed in the original post:

Does the FBI even know it is the Christmas season?

Well, Bill O'Reilly did his best to inform them, but the evil multiculturalists running our government have kept the FBI in the dark. They are operating under the assumption that it is Hannukah, Kwanzaa, and Solstice season.

[Peenie Wallie]

http://www.peeniewallie.com/archives_2005_01.htm#lasers

Airplanes, Lasers, and Terrorists....Oh My!

I?m not convinced that potential terrorists are painting planes with lasers, primarily, because I don't see any particular value in doing so. If a 'terrorist' wanted to 'terrorize', planes seem somewhat passe. Historically, terrorists have shown a propensity to diversify in their objectives and attack softer targets.

Because people are not searched when they board trains, buses, subways, and elevators, these other targets are much softer. In the Middle East, terrorists routinely detonate bombs on buses, in malls, or in outdoor cafes. In Russia, they recently successfully detonated a bomb at the screening point outside a rock concert. So, all of these, in theory, would work to achieve the terrorists goals, if their goals are to 'terrorize' and gain recognition for a particular cause.

If, on the other hand, they really feel compelled to bring down an airplane, in no way, would that goal involve lasers. It's not like there are shoulder fired missiles and rocket propelled grenades available for sale in the United States. That's not reality based thinking. If someone offers to sell you a shoulder fired weapon, I can guarantee you that it is a federal agent running a reverse sting.

Besides, the height and speed of the jets during approach and takeoff is well documented, and readily apparent. So, for the terrorists to go around all over the country, pointing laser lights at planes, to calibrate their speed or altitude would not make logical sense. Plus, it would obviously serve to compromise their plan.

Finally, keep in mind that every Muslim in the country has been interviewed, interrogated, exported, or deemed an 'illegal combatant' and incarcerated deep in the bowels of Camp X-Ray down at Gitmo. I know because I have Muslim friends. They're all too scared to answer the phone when it rings. So, to believe that there?s suddenly this broad conspiracy all over the country where terrorists are acting in a coordinated manner and shooting laser beams at planes that somehow the CIA, FBI, TSA, State, County, and City authorities all are blissfully unaware of, seems very remote indeed.

My theory is that it is either:

(a) reflected sunlight (remember, the sun is blinding if you look directly at it, or if it is deflected into your eyes), coupled with mass hysteria or
(b) possibly a government ruse along the lines of Operation Northwoods or MK Ultra.

Nothing else makes any sense. Unfortunately, we?ve allowed the TSA to operate behind a wall of secrecy, so, in all likelihood, we'll never know the true cause of these 'incidents'. Certainly, the investigation(s) into this phenomenon by the alphabet soup agencies (FAA, NTSB, TSA) will not be open to public scrutiny.

[Agent Mulder]

Don't you see what's really going on? The government is putting out this bogus story of lasers to cover up cases of pilots who were blinded by lights from alien space craft.

[The Smoking Man]

Anybody reading this blog will be liquidated by morning.

[Junyo]

One advantage an energy weapon would have over a cheaper/easier projectile weapon would be little to no forensic evidence. A shoulder fired rocket, even a .50 cal would leave tracible evidence of it's usage; a laser would leave nothing. Would a dazzler type laser weapon even damage the pilot's eyes enough to be detectable medically? Assuming there are terrorists that are not suicidal Muslims, how much extra effort/expense would a reusable, fairly hard to trace weapon be worth?

[thoreau]

how much extra effort/expense would a reusable, fairly hard to trace weapon be worth?

Judging from the fact that none of the alleged laser attacks have resulted in plane crashes, I'd say "not very much."

[Isaac Bartram]

I thought commercial jets were no longer landed by the pilots anyway. I realize pilots have to watch for malfunctions etc., but this sounds like someone's way overreacting.

[Seamus]

Wasn't there a story back in the 80s about a U.S. spy--er, surveillance--plane that was flying over a Soviet "fishing" boat and taking pictures, when a bright flash went off, and the photographer ended up with permanent eye damage? (Of course the Russkies said they had no idea what could have caused the photog's problem and there was never any conclusive proof they were responsible.) If it really was a Soviet laser that damaged the photog's eye, then it seems the problem of targeting might not be all that great.

[Cessna 152 Pilot]

On final an airliner is approaching at around 150 - 180 knots. However, that is ground speed. Since the pilot is looking forward and the windshield is on the front of the plane, you would have to be ahead of the plane. Relative motion would be the planes descent rate of perhaps 1000 fpm, much slower.

If you were located at the base of the glide slope the plane would be descending towards you and the only motion would be drift relative to the glide slope, i.e. not that fast. By using a sight and scatting the laser around in the front of the aircraft you would have a good shot at hitting the pilot and perhaps distracting, but not disabling him/her.

[Cessna 152 Pilot]

However, that is ground speed.

Sorry, I meant airspeed.

[thoreau]

Pilot-

I agree that tracking the plane from a carefully chosen vantage point would be fairly easy. I still think it wouldn't be quite easy enough to put together in a garage over the weekend, but a few skilled guys with some time could do it. My bigger concern has been the cost of getting a sufficiently powerful laser, power supply, and cooling unit that can be carted around easily.

Question for you: Are landing paths usually chosen to avoid the number of tall buildings and hills in the path of approach? My guess would be yes, because as far as I can recall takeoffs and landings tend to be in the same direction. Please correct me if I'm wrong.

Seamus-

I will have to reconsider some of my points. However, my first thought is that looking through an eyepiece at the flash means that you're collecting light from a larger aperture and hence collecting more light from the flash than the nakes eye would receive.

[Cessna 152 Pilot]

...wouldn't be quite easy enough to put together in a garage...sufficiently powerful laser...etc.

Agreed.

Question for you: Are landing paths usually chosen to avoid the number of tall buildings and hills in the path of approach?

I don't really know. Probably within the immediate range of the runway. I would guess the direction is setup so the plane is at least 1000 feet above the highpoints until the last 1000 feet of descent or so. That was the approach I remember when I was taking lessons, I haven't flown in about 10 years.

My guess would be yes, because as far as I can recall takeoffs and landings tend to be in the same direction.

Yes, the runway that is facing the most into the wind so as to have minimum groundspeed for a given airspeed.

[Seamus]

Here's one commenter who suggests that the laser isn't meant to blind the pilot. But he doesn't really put me at ease.

http://www.sgtstryker.com/index.php/archives/airline-laser-threat/

[drf]

You know, I have one simple request, and that is to have sharks with frickin laser beams attached to their heads. Is that too much to ask?

http://manofmystery.austinpowers.com/Mov/orgyb.mov

[green laser pointers]

Thank you for posting this great article.

[Nike Dunk Shoes]

thanks