Laser injures Delta pilot's eye

[lasernigel]

Loose Rivets Only too happy to answer your question,as opposed to getting sarcasm from people whose only knowledge seems to be cutting and pasting links.
Normally an opthalmologist would start to treat at a lower power than 'usual' settings.For most retinopathy a start spot size of 200 microns is used and a power of around 100mW and an exposure of 0.1-0.2 secs.What the opthalmologist is first looking for is effect eg a blanching of the sight over the vessel which is leaking and just enough to seal but not overburn on the sight.So by slowly altering the parameters for this effect the operation is carried out.Sometimes upto 2500 shots will be done at one sitting.Originally Argon lasers at 488nM-520nM were used but it was found that it was treated better and less painful for the patient if the blue light was filtered out and the green light component at 514-518nM was used.
Dye lasers at 585nM have been used as some opthalmologists think yellow light is the way to go and in fact the company I used to work for managed this using a Krypton tube with a different high reflector and filter to achieve this 561nM.
Red light can also be used to treat areas of the macula at 657nM.
No longer do diabetics have to go blind thankfully.

[FFFlyer]

Tx for the info LN, very interesting.

[Cayambe]

Not sure why all the fur is flying here. Seems there are some pretty basic facts here.

Can a 200mW laser "reach" a plane a few thousand feet above the ground? Well, it depends on the amount of cloud rain etc. and on the laser type but on a clear night with an Argon ion laser the answer is definitely yes. However, without some reasonably clever optics, the spot size would be very large by the time it got to the plane and it would be very unlikely to hurt the eyes of the pilots. They would not be dazzled or temporarily bilnded. They would notice the green / blue light and it might distact them somewhat. Clearly not a good thing. If the laser was more powerful, 10W or 20W say and somebody knew what they were doing (with a simple telescope on the end of the laser) then the potential for eye damage would be greatly increased. As a 20W Argon ion laser requires water cooling and a three phase electricity supply (not to mention about $50k to buy one) it is unlikely that yer average amateur boffin would be able to run one in his shed.

Richard Feynman was a brilliant Noble Prize winning physicist. He absolutely never said or believed that lasers could not hurt your eyes. You are confusing what he said about radiation and looking at a nuclear explosion. That had nothing to do with lasers - there are all different kinds of radiation - not just visible radiation e.g. light.

[410]

In the very same book where he predicted (or quite possibly germinated the idea of) someone crashing an airliner into a major public building, Tom Clancy had his spook heroes John Clark and the Hispanic guy (Rameriz?) zapping the eyes of the pilots of two Japanese AWACS 767s with lasers as they approached to land at their home base, causing both aircraft to crash.

Anyone interested in giving himself a goodfright might like to take a look through some of these sites.
http://nrac.onr.navy.mil/webspace/ex...8lasereye.html
http://articles.findarticles.com/p/a...90/ai_82009542
http://www.aeronautics.ru/nws002/ap036.htm

[End_of_Descent]

Talking not about lasers but about Richard Feynman again ... the full quote was printed in his collection of adventures "Surely your joking, Mr. Feynman" in the chapter "Los Alamos from Below".

True, he did not have lasers in mind but look at the original text:
"20 miles away, you couldn't see a damn thing through dark glass. So I figured the only thing that could really hurt your eyes (bright light never can hurt your eyes) is UV light. I got behind a truck windshield, because the UV can't go through glass, so that would be safe ..."

True, ultraviolet light is strongly absorbed in glass, but bright light CAN damage your eyes. I still believe that Feynman was wrong here.
Since the sun's light can damage your light, a nuclear flash might be able to achieve the same. It's all about brightness and exposure time. While a brief look into the sun should be fine, a brief look into a high power laser usually isn't. Probably the nuclear flash was just for too short a time, that's why nothing happened with Feynman.

Besides ... glasses used for laser protection in the lab are usually specially adopted to a certain laser wavelength. Glasses which keep green laser light out are transparent to red lasers. So protecting cockpit glasses just won't work for all lasers around.

EoD

[Cayambe]

410

The problem with Clancy novels and James bond films is tah they ignore the reality. A class 3 laser taht could really hurts someones eyes at a range of a 1000ft or more is a big bulky thing. You probably need a forklift to shift the power supply of some of these things. There the chance of someone hding in a crowd and shining one is pretty remote. They are not easily disguised into an Omega writs watch unlike the one that 007 has which can cut metal!!!

As my laser prof. used to say - the best way of hurting someone with a laser is to drop it on them.....

[2close]

Looking at this from the GA point of view, notwithstanding that they do not present as great a risk to persons and property on the ground, is there just as much or even greater risk to pilots of slow moving light aircraft with a sheet of cling film for a windscreen and flying at a far lower altitude?

Most of my local GA traffic tends to be between 1500 - 3500'.

I was informed of an incident not so long ago of the local pond-life amusing themselves with a bundle of fireworks and something akin to a length of scaffolding pole, knocking up a home-made RPG and firing it at (and apparently hitting) the police helicopter.

If they got their hands on this, they would really be in their elements!

Be grateful for any learned advice.

2close

[Danny]

Well, perhaps we can stop the one-upmanship between Airbubba and LaserNigel and return to debating the issue of someone maliciously or otherwise pointing a laser into a pilots face. I can assure you, from personal experience, that even a little Class III laser pointing into your eyes can cause serious, even if only temporary, problems.

A few years ago, waiting to depart at night from runway 35 at Corfu there was a "Cleatus, slack jawed yokel" who probably thought it would be amusing to stand on the road that passes less than 100m from the threshold and shine his laser into our flightdeck. I first noticed the light dancing around on the Captains face and turned to my right only to receive the red glow as it danced across my eyes a few times. As soon as I realised that there was a dipstick pointing his laser at us there followed the usual farce of trying to explain to the tower what was happening and could they please give us a take off clearance so we could get on our way.

To cut a long story short, I experienced spots in my eyes for the next 20 minutes or so. They were distracting and caused some concern for a while. THey did wear off and thankfully there was no lasting damage but to go on about how they are not to be worried about, is quite frankly, a bit of a problem. At night, whilst the eyes are accustomed to the low light level and just before a departure towards a big mountain with a turn out over a dark sea can become a few more layers in the Swiss Cheese if you are not careful.

These small lasers, never mind the more powerful ones, can cause problems even if they don't actually damage your eyes permanently. To dismiss them as being "not serious" is to ignore the circumstances of what they can do and if the dipstick who is pointing it has thought through the consequences of their actions.

[Anne.Nonymous]

Over a year ago there was an instance of a green laser tracking an A321 on finals to Heathrow at night. The Flight crew saw the green light dancing around the flight deck and could see the source north of the ILS path.

It was reported and investigated by the authorities but nothing further came of it. It is almost impossible for the authorities to act quickly enough to catch the idiots that do it.

Anne

[Daysleeper]

Well when we all get our anti SAM lasers perhaps we can mod them to fight back

[jayteeto]

Just got dazzled by a laser tonight while hovering at 1000' over Wallasey. I spotted the little s**t and we trained the NiteSun on his bedroom window. My light was bigger than his!! Seriously though, we are regularly lasered and regularly have fireworks launched at the helicopter. Sadly a fact of life these days

[Airbubba]

>>I can assure you, from personal experience, that even a little Class III laser pointing into your eyes can cause serious, even if only temporary, problems<<

Yep, that's my opinion, however unpopular in more learned quarters <g>. If I had only finished grade school...

>>Federal Aviation Administration officials are well aware of the potential dangers. A 2001 report by the FAA's Western-Pacific Region indicated that from January 1996 through July 1999, there were more than 150 incidents of low-flying planes being illuminated with lasers. In a number of those incidents, pilots suffered some visual impairment.<<

Here's the 2001 FAA report which concludes that even low powered laser pointers can somehow "get up to an airplane" and be dangerous in critical phases of flight:

"Conclusions: Laser pointers have caused ocular injury and may compromise aviation safety when used to illuminate aircraft in critical phases of flight..."

http://www.cami.jccbi.gov/aam-400A/A...0TEXT/0107.pdf

Also, from a 2003 FBI bulletin:

"...The majority of laser pointer illuminations cause reactions of startling, after imaging, or flash blinding. However, if the laser is powerful enough or sustained on the eye long enough, eye damage can occur. Additionally, bundling lasers, or "six-packs," is a technique that gangs in California have used against law enforcement helicopters. Many varieties of pointer lasers exist and some that project a beam that can reach 1,500 feet cost as little as $15. For a helicopter operating at night between 500 and 1,000 feet, laser beams can present a real threat to pilot safety."

http://www.findarticles.com/p/articl...2/ai_100876733

[Daysleeper]

ok its not a LASER but from today 2nd Oct Guardian

S**** O**** 38, of Darlington, who twice shon a powerful lamp into a police pilot's eyes, causing him to abort a landing at Teeside airport, was branded a "dangerous idiot" by judge David Bryant at Teeside crown court. Orr was given 200 hours community service with £912 costs.

[Loose rivets]

Thanks for the info LN and C, it does seem that the danger lies in the concentrated energy of relatively low energy photons - when they are combed into an ordered beam. I imagined that the photons that leave the inner surface of the windshield are not those that enter the glass, and can only have the energy that the latter glass structure can provide. Feynman threw himself on the lorry floor by the way, and could only see a huge mauve flash for the next while, but it does seem that the pilot really did come to harm; the information coming in is certainly cause for serious concern.

The UK legislated quite quickly on the random sale of cheap lasers, but the determined will still find a source. There will always be people that have no concept of responsibility for their actions. It seems that age has little to do with concern for others; the Teeside defendant being an indicator. Prior to lasers, there were the ****** that dropped concrete blocks off motorway bridges...they just don't care, they feel no compassion.

I have always been against deterrent sentencing in principal, but I feel that it is time that, after appropriately promulgated warning, that people willfully endangering an aircraft, or indeed vehicular traffic in this manner, get a lot more to think about than community service.

[lasernigel]

Thanks Danny I tried to keep my answers on this thread sensible 'til diverted by

Yep, that's my opinion, however unpopular in more learned quarters <g>. If I had only finished grade school...

If my answers and what I had written in another thread had been read properly most ppruners would have seen that at no time have I condoned the use of these or other Lasers into the hands of Joe Public.In fact am all for withdrawal of Lasers for any use other than what they were designed for e.g industrial,scientific or medical use,and IMHO some sort of licensing is needed along with hefty fines dished out to those who use them maliciously.

[Airbubba]

Apology accepted, let's move on...

[Whippersnapper]

Regardless of how effective these lasers are (and I suspect they would be very effective at short range on landing aircraft), the individuals using them are trying to endanger or destroy aircraft. By definition, this is an act of terrorism, and 200 hours community service is not an appropriate punisment. Hanging is.

[Airbubba]

Thursday December 30, 11:34 AM

FBI Probes Laser Beam Directed at Cockpit

Authorities are investigating a mysterious laser beam that was directed into the cockpit of a commercial jet traveling at more than 8,500 feet.

The beam appeared Monday when the plane was about 15 miles from Cleveland Hopkins International Airport, the FBI said.

"It was in there for several seconds like (the plane) was being tracked," FBI agent Robert Hawk said.

The pilot was able to land the plane, and air traffic controllers used radar to determine the laser came from a residential area in suburban Warrensville Heights.

Hawk said the laser had to have been fairly sophisticated to track a plane traveling at that altitude. Authorities had no other leads, and are investigating whether the incident was a prank or if there was a more sinister motive.

In Colorado Springs, Colo., Monday night, two pilots reported green pulsating laser lights shined into their cockpits. Both the passenger plane and a cargo plane landed without problems.

Police dispatched patrol cars and a helicopter to a neighborhood to investigate but found nothing. FBI agents were continuing to conduct interviews, agency spokeswoman Monique Kelso said.

Federal officials have expressed concern about terrorists using laser beams, which can distract or temporarily blind a pilot.

A memo sent to law enforcement agencies recently by the FBI and the Homeland Security Department says there is evidence that terrorists have explored using lasers as weapons. Authorities said there is no specific intelligence indicating al-Qaida or other groups might use lasers in the United States.

In September a pilot for Delta Air Lines reported an eye injury from a laser beam shone into the cockpit during a landing approach in Salt Lake City. The incident occurred about 5 miles from the airport. The plane landed safely.

Lasers are commonly used in a number of industries and are featured in outdoor light shows.

The FAA mandates that laser light shows must register their locations and the lights cannot be directed above 3,000 feet. Lasers are also often used by construction companies to line up foundations.

Interfering with a commercial flight is a felony punishable by up to five years in prison.

http://asia.news.yahoo.com/041230/ap/d879nei00.html

_______________________________________________


Green Lights at Airport
Lasers Cause Problems For Pilots

Associated Press

Federal officials are investigating reports from two pilots who say bright lights were aimed from the ground into their cockpits as they headed into the Colorado Springs Airport.

Both planes landed without problems on Monday night.

Federal officials issued a warning this month that terrorists might try to down aircraft by shining powerful lasers into cockpits to blind pilots during landing approaches.

The pilots heading into Colorado Springs about 8-30 p-m Monday reported a bright, pulsating light shining into the cockpits. Colorado Springs police say the pilots described the lights as "green laser lights."

F-B-I spokeswoman Monique Kelso says authorities haven't determined what type of light was used, and F-B-I agents are conducting interviews.

http://www.kktv.com/home/headlines/1309846.html

[Memetic]

Lasers for aviation.

A bit off topic but I stumbled across a site for this Alaskan company making LASER "flares" and LASER airport markings which might be of interest to some of you.

[rotornut]

Does anyone recall the incident involving a U.S. military plane a few years ago? Apparently it was alleged that the pilot was blinded by some kind of laser device from a Russian freighter or trawler off the B.C. coast.