No.
By creating a mirror that swivels back & forth very rapidily, you could reflect a laser off of it, & traverse the beam over every square centimeter of any given targeted area . Covering the entire cockpit, or even the entire nose of an aircraft could be done in a second or two. You could do this at range, from a variety of angles.
Similar equipment exists “off the shelf” for use in laser light shows, & I suppose that it could be adapted quickly enough.
But then, I’m not a technician.
Yes, I agree you can paint a spot on an airplane the way you describe (which is what I eluded to by the term photons per second/per square inch). However, you can’t paint the inside of the cockpit by standing inline with the runway because the pilot can’t see that on final. Once the plane is stabilized on approach the view of the runway never changes. The beginning of the runway is the lowest point on the horizon the pilot can see (looking straight ahead). You may have to draw yourself a picture to understand this. The airplane is either parallel to the ground or slightly nose-up on approach. Everything inline with the runway is out of view.
If you were not inline with the runway then you have to illuminate the cockpit from the side and that would require the pilot to look in that direction. On approach, a pilot is either watching instruments, the runway, or the surrounding airspace on his altitude (aircraft avoidance). The classic example of Russian ships illuminating aircraft is a different thing altogether because the intercepting aircraft would probably establish the ship as a turning point and the pilot would specifically stare at the target out the side window to maintain a reference point to turn on. This is the same maneuver a gunship would use to strafe a target.
To use a laser effectively it would have to be done in-line with the runway. This would require sneaking onto the airport (easy to do) or firing the laser from the other side of the airport which would involve an additional 2 miles of distance (most runways are 8-10,000 feet long). If a terrorist can buy a blinding weapon on the black market they could also buy a shoulder-fired missile which would give them much more latitude in location.
No it’s not. Speaking from experience here. When you’re on final for the runway, there is an awful lot of stuff still visible above, below, and to the sides of the runway. Are you a pilot? If so, think about it - if you’re making a landing, can you see the approach lights on final? Of course you can. You can, in fact, see the other end of the runway, and even a few miles beyond. I know this, because once I was on final for landing in Cheyenne Wyoming, which was uncontrolled at that time, and about a mile back I spotted another aircraft landing on the same runway from the other direction. He came in against the pattern, without making a single radio call. I executed a miss and went around again.
If you’ve got MS Flight Sim, fire it up, set yourself up on a five mile final, and see just how much stuff you can see out of your windscreen.
You guys are making this all sound way too hard than it is. Really. Beam splitters, mirrors… Look: just attach the laser to a rifle stock, put a good scope on it, and you’re done. Being an avid aircraft watcher when I was a kid, I used to go out to the airport with binoculars and watch airplanes landing all the time. I had NO TROUBLE tracking them with powerful binoculars or a spotting scope. I could zoom in close enough to see features on the pilots. Unless it was horrifically turbulent, the aircraft were just trivial to follow. And the laser can stay on all the time. As I said before, you guys are probably thinking about how difficult it would be to shoot a pilot with a gun, but this is an entirely different class of problem. If the laser only fired once for a millisecond, I’d agree that it would be a difficult shot. But the laser is on constantly. I can focus on this plane, flip on the laser, and just start painting around the cockpit until I hit someone. Give me a couple of sandbags for stability and a prone ‘shooting’ position, and I don’t see the problem.
:eek:
I hearby nominate Sam Stone as SDMB’s official “person of interest”!
From the Target store parking lot near O’Hare, I can see up to nine planes coming in for their approach lined up like beads on a string. They don’t seem to move very fast across the sky to me when I stand there. My daughter loves watching them. It is perfectly plausible that there is a place like a parking area in a forest preserve near O’Hare that would be be right along the approach as well as publicly accessible and yet relatively unoccupied most of the time. Heck, the Target parking lot frequently has one or two lurkers like me there to watch planes, or waiting, eating their Krispy Kremes, for someone to call that they arrived at the airport. People who just sit and watch the planes won’t draw suspicion. If they are careful they could do more than just watch.
I think it is more possible thatn we would like, but less likely than we fear.
I agree 100%. I can’t think of a single aircraft which would obscure the runway, or a significant area around a runway, while on final approach. Hell, the only time I think a runway would ever be obscured from a cockpit is if you’re in a taildragger that is stationary and holding on the numbers.
Here’s a photo from a cockpit of a 747 on short final: link. Note that the horizontal green lights on the runway mark the beginning of the runway. Once stabilized on final, that view of the runway will remain pretty constant throughout the descent of the plane, whether the aircraft half a mile out, or if its on a five mile final. There’s no way to argue that the runway is obscured during a straight-in approach.
There’s no need to shoot from the side. A position beyond the centerline of the runway would be ideal.
Sam, yes I’m a pilot. I have a better downward view than most Cessna’s. I Don’t understand your missed approach analogy because everything beyond the landing point is in view. Which was my early point that you COULD be on the other end of the runway and target a cockpit. Also been on the “other aircraft coming at me at the same airport” missed approach. It was right after they came out with CTAF frequencies as I remember.
Ravenman your link proves my point. What you are looking at is VERY short final. You will see the same view of the runway once you turn on final (just farther away). The approach lights are there to que you up. Once you trim for the glide slope you will be parallel to the ground or slightly nose up. Otherwise you will auger into the ground like a lawn dart. Most of everything INLINE and BEHIND the runway will be out of view of the pilot. It would be better to try to tag a cockpit on the base leg when the pilot is actively (visually) flying the airplane.
I’m not saying LASERS can’t be used. I’m saying they have limited use in an airport setting. Certainly much less than a Stinger missle. I certainly hope terrorists are wasting their time on this concept.
The thing is, getting your hands on a blinding laser is trivially easy. It’s cheap and easy to do. But, in my opinion, ineffective in bringing an aircraft down. So perhaps what we saw before was a test - some terrorists had the same discussion we’re having, and decided to just go and try it. Didn’t work out so well from their perspective, so perhaps the notion has been dropped.
I’m extremely confused.
First, you said this: “However, you can’t paint the inside of the cockpit by standing inline with the runway because the pilot can’t see that on final. … Everything inline with the runway is out of view.”
Then you say this: “I Don’t understand your missed approach analogy because everything beyond the landing point is in view. Which was my early point that you COULD be on the other end of the runway and target a cockpit.”
All I’m saying is that both pilot and copilot can see the centerline of the runway during the entire approach. Someone standing beyond the departure end of the runway, along an extended centerline, could easily be seen by both pilot and copilot. If that person can be seen, then he has a sightline to the cockpit, and could, in theory, target their eyeballs with a laser.
My apologies for not getting back to you on this. However, my premise that landing at night would be more difficult for people on the ground to see said aircraft has been refuted in the ensuing debate.
More importantly, it’s good to see the Doper Air Force contingent chimed in with their collective thoughts on the subject.
Yes, everything from at least 500 foot prior to, and everything beyond the beginning of the runway is in view. As I’ve pointed out, using a LASER from the beyond the end of the runway adds 2 miles to the project and once you’ve trimmed for final you could fly it blind and still land. On final an aircraft is trimmed for landing including the engine power settings. All the pilot has to do is listen for the outer and inner marker beacons and the tower could call out the final flare- out. Might not be a pretty landing but everyone would walk away. If it’s a major airport it’s set up for CAT-3 landings so the airplane will literally land itself.
I’m with Sam. It’s possible but it’s not keeping me up at night. Other things are, but not LASERS.
Well, guess I should post this. Just saw this on the local evening news. Someone tried to blind a civilian helicopter with a green laser. Didn’t work but it was tried. Brought out a lot of law enforcement looking for the person(s) responsible. Maybe I spoke too soon about the likelyhood of any serious attempts.
No I don’t have a link.
Checked Google news, no links yet.
Another airplane was hit by a laser in Ohio. This one was in Cleveland and involved what was speculated to be a red industrial laser. The plane was at 8,500 feet so that means someone was able to track a cockpit (for a number of seconds) which was moving at 300 mph and 1 1/2 miles above the ground. IMO this would require a tripod and something that allows for controlled movement.
Found out from the local news that the other incident was in Clark County which is hundreds of miles from Cleveland.
It occurs to me that if you had told me on September 10, 2001 that you could use common, everyday boxcutters to set in motion a chain of events that would lead to 3,000 dead by the end of a morning I would have told you that you were full of it. By noon on September 11, 2001 we all knew differently, didn’t we?
Are lasers in the same category as boxcutters? Simple tools that have an unforeseen potential for mass murder? Or is it impractical? And is someone trying to make that determination right now?
I do think most discussions of using lasers to down airplanes get overly complex and suffer from the worship of high tech. You don’t need high techonology to kill people. Rocks and sharp pointy sticks still work as well as they ever did.
And now, we have a similar incident at NASHVILLE INTERNATIONAL AIRPORT.
I work at the airport. I find the proximity strangely unnerving.
So far most of it looks to me like overaged kids but the Cleveland event involved the ability to track something at 8,500 ft that wasn’t even in approach airspace. BNA was also disturbing. The box cutter analogy is not far off. If this is a media fed event then the assholes doing this will eventually stop. However, one of the MO’s of OBM style terrorism is preplanning and the testing involved.
I tried my presentation laser on a stop sign 300 ft away and was startled by what I saw. The pattern seemed to be much wider than when used indoors so if there is the same spread (over distance) then a more powerful laser would really light up a cockpit. It might just be that the stop sign was highly reflective and I was seeing subtle movement spread over the sign. Also might have been some defraction out of my bathroom window. Don’t know.
We have outdoor laser shows in my area so I’m use to the aviation warnings to avoid them but one of the Ohio laser events was in Clark County which is an area I often fly through. Hopefully the lasers that can be purchased on the internet are not as powerful as the ones used in outdoor shows.
You can purchase lasers of almost any power over the internet. Certainly lasers more powerful than what would be used in a typical laser show.
For example, here’s a company that will sell you a 100 Watt CO2 laser for $12K. A 100W laser will cut metal.
The laser in question might have a beam divergence of .2 mR or so with decent optics, which means the beam will grow in diameter by .2mm for each meter of distance. So if an aircraft is 2000 meters away, the beam will be 400 mm in diameter. At that distance as well, the power density of the laser will have decreased to 1/160,000 of its original, leaving a power density from a 100W laser of .625 W (assuming the original beam was 1mm thick). 625mW is far more than what would be necessary to blind someone.
At 5000 m, the beam would be 1m across, and the power density would still be 160mW. With a good scope mounted on the laser and a reasonably solid base to ‘shoot’ from, I think you could have good success hitting planes. By ‘good success’ I mean that if you sit there all day trying to hit planes flying over, you might get one. That’s all that’s necessary to make the news and scare people.
You’re not going to crash a plane, but if you’ve got every pilot in the country worried about being blinded on every flight he makes, you’ve ‘terrorized’ the industry. If you’ve got passengers always wondering if their flight will be ‘shot down’, you’ve done the same. Given the very low cost of entry and the low likelihood of being caught, it may be worth it to terrorists even if they know they almost certainly will not bring planes down. They’re gumming up the works.
Oops. I used diameter instead of radius in my calculations. Cut the distance in half and the numbers work out. For 5,000m, the power density is actually 25mW, which is still more than five times more powerful than the most powerful laser pointer, which are limited to 5mW of input power. A 5mW laser pointer can damage your eyes if you look into it for more than about 5 seconds.
By the way, a pilot gettting hit by intense laser energy at 8,500 ft or even 2,000 ft is NOT getting hit by a laser pointer, because they have pretty big beam divergence, typically around 1-2mR. A laser pointer is not dangerous past a few dizen feet at most, and at a mile the beam would be almost undetectable, or seen merely as a bright point of light on the ground. It certainly wouldn’t be ‘blinding’. Shining a laser pointer even across at the houses 1/4 mile away results in a beam that’s a couple of feet across and almost invisible.
