Ah, Flight 999 You Are On Terrorist Laser Approach ... Close Your Eyes ...

Great Debates
21

Not to mention literally the easiest thing possible to aim.

However, if someone did manage to rig an industrial laser to a scope, and then managed to get a good inside view of the cockpit, and then managed to blind both pilot and copilot, what are the odds that no one else in the plane would be able to follow the pilot’s instructions? Sure, an unskilled person landing a commercial aircraft wouldn’t be easy, but it’s hardly %100 certain that a crash will occur, especially with the pilots to point out exactly where the proper instrumentation is.

That, coupled with the fact that any laser capable of doing severe harm will, by definition, be well regulated. There will probably be a paper trail, and I don’t think the terrorists will risk getting one of their own caught on the off-hand chance they might be able to cause a crash.

Sure, they will not only cause some blindness but also engender additional terror in the flying populace. But I don’t think it will be worth it to them, there will probably be more fruitful avenues to attempt.

Call me back when they have lasers that can take down an aircraft (probably only a couple decades away,) then we’ll be in trouble.

22

You need to spend some time at an airport watching aircraft come in for landing. I used to work at an airport, and watched thousands of planes land. It’s not nearly as difficult as you think. These planes aren’t bobbing and weaving all over the sky - they’re on final approach, in a smooth, steady descent. From the ground they look almost stationary.

Again, I just don’t think it’s as difficult as you all seem to - you have lots of time - minutes - to get your aim right. You can sweep the laser back and forth over the front of the airplane continuously.

As for where to take the shot - anywhere along the final flight path, or even just sitting in the parking lot of the airport. Find the right airport, and you might even have a high elevated spot like a rooftop that looks right into the cockpit.

23

I have. I am an aviation buff and a pilot. Those cockpit windows are pretty small from over a mile out and that is the last end of the range. Combine that with the fact that you laser has to pass through those windows and yet still hit someone in the eye. That is almost impossible at even 100 yards given a moving target. Even if you took out the pilot or the co-pliot, or cannot see how you would take ot both. For one thing, the windows are curved so whatever position you get on one won’t work on the other unless you are directly in front of them and that increases the range even more. This is not an effective plan.

24

Another Doper pilot checking in.

Question 1: Are there lasers powerful enough to blind instantly?
Answer - yes.

They can be found in both industry and medicine

Question 2: Is it possible to target an airplane cockpit on final approach to an airport?
Answer - yes.

With a variety of weapons. Five miles out from an airport an airplane is only a couple thousand feet up, well within the targeting range of many weapons. Granted, they tend to be moving rather quickly, but hey, if the first attempt doesn’t succeed you likely will be able to try multiple attempts.

Question 3: Is it possible to use a high-powered laser as a weapon to blind pilots?
Answer - yes.

Questions 4: Is it likely?
Answer - probably not.

Question 5: Would such an attack cause an airplane crash?
Answer - probably not

You’d have to blind both pilots in a relatively short period of time. If pilots observe odd lights in or about the cockpit and one of them suddenly screams ***AAAAAAIEEEEEEEEE! I can’t see! * ** the other will probably execute a missed approach immediately just on the “WTF just happened? I better reduce the number variables here by going up where we can’t hit anything while we sort this out.” principal. Would probably do that even if strange lights hadn’t been noticed.

The biggest effect - other than one or two unfortunates blinded for life, which is bad enough - would be to inspire fear and terror among the general populace. If you goal is terror along with or instead of a high body count, this may be an effective tactic IF you can work out the details.

Queistion 6: Is this something that you, as a pilot, worry about?
Answer - no. Nor do I worry much about shoulder-launched rockets, bombs on board, or the wings falling off. All of those are possible, but bird strikes and bad weather are MUCH more likely to ruin my day.

25

Shagnasty: I’m also a pilot. I don’t get where you get the ‘high speed’ stuff from. What matters is not the speed of the aircraft, but the relative change of position from the perspective of someone looking straight on at the aircraft.

For instance, you no doubt learned that one of the ways you can tell if an aircraft is on a collision course with you is if its position relative to the windscreen of your aircraft remains fixed. That means that from the perspective of someone trying to aim at an aircraft coming straight at them, it isn’t moving at all, even though the closure rate may be 700 mph.

if you stand right beside the VASIS lights on a runway and watch a jet coming in on the glidepath, it will appear to be stationary. No motion at all. Aiming at such a target with a laser is just not difficult.

Again, we’re not talking about shooting a gun. With a gun, you have wind effects, time delay while the bullet reaches the target, and one impact point. I would agree that shooting a pilot with a gun would be extremely difficult.

But a laser is totally different. There is no time delay. There is no bullet drop. No wind effects. What you aim at is what you hit. And, because the laser is continuously on, all you have to do is aim it in the vicinity and then sweep back and forth. With a very high power laser, it only takes a short exposure to blind the pilot.

Finally, consider that the terrorist can miss 500 times in a row before being successful. There are no gunshots, no visible beams, nothing to alert anyone on the ground that someone is trying to blind a pilot - until he succeeds.

26

Those of you who are arguing that it would be difficult to hit an airplane with a laser at a distance are probably assuming a tightly focused beam like that cast by a laser pointer. But even a well-collimated laser beam will spread over a long enough distance. And if you think of a high intensity beam a foot or two across, this becomes much more plausible. It’s easy enough to track a moving target with a laser, after all – the speed of the target doesn’t really matter because you only have to move the laser a tiny fraction of a degree to follow even a fast moving object.

Although far from being a terrorist threat, I’m much more likely to believe that the reported laser incident was some yahoo fooling around with a powerful laser from Edmund Scientific, or even one of those newfangled green laser pointers.

27

The reason that I mentioned the speed was because I seriously doubt that a potential terrorist with a laser would be looking at it straight on. That would mean that the terrorist is either standing on the runway itself or has some odd line of sight directly down the runway. If it is still a direct line of sight down the runway but away from the airport, then we are looking at about two miles added to the distance. A shot to the side would be much more difficult both because of the speed of the aircraft and the angle of the windows.

I am not saying that it absolutely impossible. I am just saying that if I were a terrorist, this scenario would be fallback plan #1543.

28

I don’t think it’s likely either, but not for the reason that it’s tough to do. The better reason is because it’s ineffective. Even if you blind the pilot, you have to blind the co-pilot at the same time or they’ll just execute a missed approach and try again with the co-pilot flying, perhaps this time with his head under a visor so he can’t be hit in the eyes.

But the actual act of hitting a plane on final wtih a laser seems pretty easy to me. And you don’t have to be right on the runway - out in the parking lot would be fine, or on a rooftop from a house on the final approach path, or from a hill. There are hundreds of large airports in the U.S. - all you have to do is scope out a few that have suitable vantage points along the flight path.

For instance, here in Edmonton we have highrise apartments within a couple of miles of the airport. We have skyscrapers 2000’ off the final approach path to runway 34, where you’re actually looking straight across at the aircraft. My office is in one of them, and I can tell you that the planes sometimes pass so close you can *see the pilots sitting in the cockpit. Hitting them with a laser from there would be trivial.

29

Before answering that question, please answer mine: why did you italicize the “at night” part of your statement? As I have said, spotting planes on final approach at night is loads more easy than it is during the day, especially at longer distances. That’s because it is very. very easy to see a plane at night, because its lit up with stobes, navigation lights, and, on final, landing lights as well.

It’s actually harder to spot a plane at five miles during the day. Hell, I can vividly recall several times when I have been on and early downwind at airports without radar systems, and the tower couldn’t spot my Cessna 172 from a mile and a half away. That would never, ever happen at night.

As for laser technology, I have no idea if terrorists have dazzling or blinding lasers. I don’t know too much about the technology. From what I’ve heard, however, dazzling lasers don’t require that you actually focus the beam on the eye for an extended period of time; it’s my understanding that the laser only has to make contact with your peepers for a fraction of a second.

That being said, I completely agree with Sam Stone. I don’t think it’d cause a crash. If I were blinded on final, I’d push the throttles wide open, retract the gear and flaps, gain altitude and declare an emergency. I certainly wouldn’t continue with the approach… the only thing I’d really worry about is pulling up too much and stalling the plane, but there’s always the stall warning buzzer. I just can’t see that this type of attack would be that effective.

30

If the government approves :rolleyes:, they can let the pilots fight back with mirrors.

31

Even assuming a terrorist with a powerful laser standing on the end of the runway, how would he power the thing? Doesn’t a powerful laser require a substantial power supply? I honestly don’t know----

32

I honestly hope that we don’t have to worry about terrorists standing right next to the runway pointing things up at planes. That’s the kind of thing that airport security really ought to notice.

And from any other position there will be relative motion between the source and the target, either mostly vertical (if the shooter is standing in line with the runway but not next to it) or both vertical and horizontal. The fact that the motion is usually relatively smooth is only of limited help to the shooter: the shooter still has to track that motion from a large distance to hit a very small target. I have a hard time smoothly tracking things 100 feet away with binoculars. I’ve no doubt that there are trained snipers capable of the type of shooting we’re discussing, but I still doubt that this is within the abilities of the average terrorist off the street.

A foot or two across? Are we suddenly discussing laser bazookas?

If a beam is powerful enough to cause instant blindness and is a foot across at its source, a terrorist wouldn’t have to use it on airplanes; they could set the pilot of Marine One on fire from the National Mall.

And if it wasn’t a foot across at its source, but became a foot across after travelling five miles, then the intensity of the beam would decrease by the square of the increase in beam radius. In other words, 1/2 inch wide -> 1 foot wide means the intensity drops by a factor of 1/488; such a beam would no longer be powerful enough cause permanent harm to the pilot.

33

Well, we’re going to have to disagree. Have you ever used a spotting scope to follow a bird in flight, for example? Much more difficult than tracking a huge plane on a constant trajectory. And yet, it’s really not that hard. And the laser is on ALL THE TIME. All you have to do is get the plane in your scope, then ‘paint’ it with the laser, sweeping back and forth over it until you hit the pilot’s eyes.

This just isn’t a hard task. Hunters use laser rangefinders all the time to get the distance of far-away objects. The motion of the plane is simply not a problem - even if you’re a few hundred yards from the runway, the angular change is going to be gradual.

So it’s easy to do, but relatively useless. Unless your goal isn’t to cause the plane to crash, but to simply add one more complication to aviation.

34

As for the power supply, you don’t need much. Batteries will be fine. We’re talking about perhaps a 5W laser, switched on for no more than a few minutes. We’re not cutting steel here - just damaging someone’s eyes. You can do that with a few milliwatts. I imagine a laptop battery would be more than enough juice, and the laser itself is small enough to mount on a rifle stock with a scope. No problem.

35

A number of points to consider.

  • An airplane 5 miles out is basically on final and is traveling at about 140 to 150 mph. it is stabilized on a descent designed to arrive at a specific point on the runway so the glideslope is pretty close to the same among all the planes landing.
  • Every airport in the United states is surrounded by land accessible to civilians which includes Airforce bases. If you look at any military base now there is a good chance you will see where they have deliberately thinned tree and bush lines along (and to the side) of their approaches. This is not a beatification project.
  • A laser does not have to emit a beam a foot wide to introduce a beam of the same width (think photons per second/per square inch).
  • The Russians have used infrared lasers against US pilots for years. It’s not high tech, and it’s not expensive to produce (as weapons go). These weapons were designed specifically to blind pilots so a 5-mile final approach would be a logical use by terrorists. It’s quite conceivable that these portable weapons were sold by soldiers wanting a pay raise. Just as it is conceivable that surface-to-air missiles may be sold on the black market.
  • While lasers will do permanent damage to the eye it doesn’t require permanent damage to endanger an approaching flight and it doesn’t require a laser to do that damage.
36

Magiver mentions the precedent for the use of lasers by the Russians against pilots. Here’s a link to a Pentagon report of such an incident that occured a few years back between a Canadian military helicopter and a Russian spy trawler in Puget Sound. What’s interesting is that while the report says that the US Navy lieutenant aboard the helicopter did receive laser-induced injuries, investigators are unsure about what type of laser has the capability to have done this. It would seem that if the technology existed seven years ago to fire a laser from a bobbing ship and “paint” the cockpit of a highly manueverable aircraft like a helicopter with enough longevity and/or power to harm someone, then it’s not too far a stretch to believe that a well-funded terrorist may have that same technology today. And if so, he should find hitting an airliner on final approach to be relatively easier.

37

Sam, I still think you’re underestimating the distances involved. Five miles is a very large distance from which to track a moving object, even with a tripod. Five miles will take you from La Guardia airport all the way to Central Park, or most of the way from LAX to downtown Santa Monica. The entire city of Calgary, AB is only about 12 miles wide.

So let’s say you’re a hypothetical laser terrorist. You’ve set your laser beam up on a tripod, and to move it you’re holding it at a point 1 foot from the pivot point. You spot the plane at the centre of your reticule, but the cockpit isn’t centred. So you adjust your aim, moving your hand 1/16th of an inch. In response, five miles away the point behind the centre of your reticule moves the following distance:

(1/16 inch) * (5 miles) / (1 foot) = 137.5 feet.

Just how big is that cockpit window, anyway? Maybe 20 feet by 5 feet?

Granted, a beam splitter will let you hit the plane with the equivalent of a fusilade. But without one, hitting the cockpit would be a matter of dumb luck.

There, I have to admit you’re right: I worked out the geometry and was surprised by the result. Assuming the plane is five miles out, travelling at 140 mph as per Magiver’s post, along a path 15 degrees above horizontal (that’s an estimate, obviously), and assuming the “shooter” is an additional mile beyond the landing point in the line of the flight path, then the angular change is only 3.6 degrees per minute. I admit I was expecting the number to be higher.

More cost-effective for the terrorist to just apply for jobs with the TSA, I would think :slight_smile:

But a increasing the width of the beam would decrease the intensity by the square of the change in width, as I already said. If we’re only talking about dazzling the pilots then that’s not a big deal, but actually causing permanent injury to the pilots this way is another story.

38

Five miles is a long way, but you don’t have to hit it five miles out - you can hit it a half mile from the runway, when it’s at 300 ft and you’re staring straight into the cockpit from the top of your high-rise building.

And hasn’t it been established that SOMEONE managed to hit that pilot’s eyes with a laser? That would indicate that it’s not impossible, and I’m not for a second buying into the notion that it might have been some secret government thing.

Anyway, I think we’ve beat this one to death.

39

Agreed, time to bury the dead horse…

… but you distance calculators are wrong. I can think of a way to bring a laser much closer than a mile to a landing aircraft, and it wouldn’t arouse suspicion, and it doesn’t involve a skyscraper near the glideslope. Ya’ll are thinking a bit two dimensionally about this, but maybe that’s OK - how detailed do we want to get with this anyway?

40

Actually, to hit a pilot in the eye you would have to be: on the runway, behind the runway, or off axis. Once a plane ques up on the glide slope the pilot’s line of site remains constant. In other words, the begining of the runway stays constant in the lower part of the pilot’s view.