- Hello, Jeff - So much for Homeland Security. I feel less
secure then I did in 2001. A laser that can be directed into an airliner
flying almost 2 miles above US cities must be technologically sophisticated.
- Just as a matter of curiosity, I wonder how many America
hating illegals have crossed our borders into the US since 9/11? They move
about our communities unwatched and unchallenged.
-
- If the laser originated in a residential community, didn't
someone see something? We, as citizens, need to be very vigilant because
our own government and homeland security is not.
-
- Patty
-
-
- FBI Investigates Laser Beam Directed Into
Airplane Cockpit
-
- CLEVELAND (AP) -- A commercial
airliner traveling at 300 mph almost two miles over northeast Ohio was
preparing to land when a green laser beam invaded its cockpit.
-
- The FBI is investigating whether the incident was a prank
or if there was a more sinister motive. The airliner was not affected.
-
- The inbound flight from Washington, D.C., was about 15
miles from Cleveland Hopkins International Airport on Monday when the beam
shined inside the cockpit, according to the FBI.
-
- "It was in there for several seconds like it was
being tracked," FBI special agent Robert Hawk said.
-
- Air traffic controllers used radar to determine the laser
came from a residential area in suburban Warrensville Heights. The FBI
has no other leads on a suspect.
-
- 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 to blind pilots during landing approaches.
-
- In the past year, there have been several reports throughout
the United States of laser lights directed at commercial flights. None
of the lights have affected the flight of any aircraft.
-
- In September, a pilot for Delta Air Lines reported an
eye injury from a laser beam during a landing approach in Salt Lake City.
-
- Interference with the flight of a commercial airliner
is a felony with a maximum penalty of five years in prison.
-
- Hawk was unaware of anyone being arrested in any of the
previous cases.
-
- The episode in Cleveland had to involve a fairly sophisticated
laser and a system that could track the airplane as it traveled 300 mph
at 8,500 to 10,000 feet, Hawk said.
-
- Hawk did not know what type of laser was directed at
the airliner. He would not identify the airline, except to say it was a
commercial flight.
-
- FAA regulations mandate that laser light shows must register
their locations and the lights cannot be directed above 3,000 feet. Lasers
also are often used by construction companies to line up foundations.
-
- Pat Smith, spokeswoman for Cleveland Hopkins International
Airport, declined comment on the incident.
-
- http://www.tkb.org/NewsStory.jsp?storyID=49096
-
-
- Patricia A. Doyle, PhD
- Please visit my "Emerging Diseases" message
board at: http://www.clickitnews.com/ubbthreads/postlist.php?
Cat=&Board=emergingdiseases
- Zhan le Devlesa tai sastimasa
- Go with God and in Good Health
-
-
-
- Comment
- From John Albrecht
- 12-31-4
-
- Jeff,
-
- re: "FBI Investigates Laser Beam Directed Into Airliner
Cockpit"
-
- Here is some science behind the alleged laser targeting
of aircraft.
-
- Few airliner cockpits are fitted with coherent light
detectors, so there is no way to verify an incoming light "beam"
is in fact a laser. It can just as easily be a refracted part of the spectrum
from a defect in the windshield, a reflection from a swimming pool (which
I can agree is very bright from up in an airplane), or coloring provided
by atmospheric conditions. Some airplanes have a portion of the windshields
tinted or drop-down tinted shades for use by pilots. These could change
the color of any incoming light. I've seen "green light" in the
windows of an aircraft during several regular flights.
-
- As for the claim that "sophisticated tracking would
be needed" to guide a laser, that isn't accurate. At the distances
reported it doesn't take a sophisticated aiming system to keep a "laser"
on a plane. A common gunsight would do just fine.
-
- As for claims that pilots can be easily blinded by ground-based
lasers, that is open to debate.
-
- Here's why.
-
- The farther the "target" is from the "laser",
the larger the area covered by the "end" of the beam. It's not
hard to aim a thousand foot-wide "spot" onto a moving cockpit.
-
- This is because even well-focused laser beams spread-out:
due to optics, and due to atmosphere.
-
- Because the beam spreads out, this also means the power
of the beam weakens...a LOT.
-
- I'm including some very rough approximate calculations
of beam power for consideration. It will be shown that it is quite a challenge
to pump enough energy into the plane cockpit to injure or blind a pilot
assuming distances suggested in various articles.
-
- At a horizontal distance of 10,000 feet and an altitude
of 10,000 feet, a laser beam with a divergence of 5degrees will produce
a beam-spot about 1200 feet in diameter. That is not going to blind anyone...the
power per square inch just isn't there. That "spot" covers more
than 1 million square feet.
-
- If we assume an easily obtainable commercial laser, or
even an also easily home-buildable laser of 100 watts, that's about 600
billionths of a watt per square inch at the cockpit in the report....and
that ASSUMES no weakening of the beam due to atmospheric thermal effects
or absorbtion and refraction by moisture in the atmosphere all of which
are very likely. The end result, is that such a laser beam will be harmless
at that distance.
-
- You can get more energy pumped into your eye from an
ordinary camera flash.
-
- In this case, even if you used a 10,000 watt laser, the
power is still only a few thousandths of a watt per square inch by the
time it reaches the cockpit window.
-
- The light loses even more power going through the cockpit
window.
-
- In addition, the light not only has to be powerful enough
to cause damage to the retina, it has to be focused by your eye on the
retina long-enough to cause damage.
-
- You would have to use an extraordinarily powerful laser
beam to cause eye damage in this particular situation. This would be in
the research or military category of laser, and you're not likely going
to be able to carry it around easily.
-
- At the distances in the article, you have to have the
combination of extremely high-power, low-divergence, relatively close proximity,
low-losses, and time-on-target in order to cause damage to the optic nerve.
Achieving all of these is an incredible feat.
-
-
- A thought that concerns me is that these unverified claims
are going to result in a huge cry for "licensing" or "registration"
of lasers. That is not only doomed to fail, it won't do anything to improve
airline safety, and will divert funds from activities that COULD improve
airline safety.
-
- Lasers are too easy to buy, transport, and can even be
made from scratch using common materials with VERY little cost or experience.
The only thing that "licensing" or "registration" will
do is increase costs to laser-using product manufacturers who will pass
along the costs to the consumer. We will also have to pay even more taxes
to support the licensing agencies, personnel, and computer systems. And
the end result is they will still be unable to stop anyone from using a
laser any way they want to.
-
- The only approaches that have a chance of impacting this
perceived threat are stiff prosecution of people misusing the technology
to cause harm, and active defensive measures.
-
- If lasers are PROVEN to be a legitimate concern, then
the appropriate response is to outfit the cockpits with laser-light detectors,
and either provide laser goggles for pilots to wear during take-offs and
landings, or use cockpit window screens and laser-resistant cameras to
provide images for the pilots during those periods.
-
- Under those conditions, it might also make sense to ensure
that at least one pilot is wearing the goggles at any altitude less than
say, 5000 feet. It doesn't take much to render safe even a very powerful
laser used from a distance of a few thousand feet.
-
- In fact, it makes sense to me to first outfit some airliners
with laser detectors (capable of recording intensity levels) just to see
if in fact this is a real problem. This would be a relatively cheap way
to determine if laser-targeting is in fact occuring, and if it in fact
presents a safety problem. It should be remembered that briefly looking
into the sun causes blindness, too.
-
- From what I've read in the news, I'm more concerned about
the potential of a terrorist targeting airliners using laser-guided or
wire-guided missles, or even large-caliber automatic weapons during takeoffs
and landings. The missles have a range of many miles... using lasers to
try to blind pilots is ineffective at best beyond a few thousand feet.
-
- Regards,
- John Albrecht
-
- Here is a table of APPROXIMATE beam power assuming different
angles of diveregence in the laser beam at a distance of about 14,000 feet
and at 1,000 feet from a theoretical cockpit. Keep in mind these figures
do NOT includes losses from the atmosphere, the windows, or other aspects
of laser technology. It should also be noted that at 1,000 feet, and with
a smaller divergence laser, the "spot" is MUCH smaller than at
14,000 feet, and it becomes much more difficult to keep the laser tracking
the window of the cockpit (for example, at the 1/2degree divergence, at
1000 feet, the "spot" is only 9ft wide). Also, the more you
want to reduce the divergence angle, the higher quality your laser and
optics must be.
-
-
- Beam 100W laser 100W laser
- Angular per square inch per
square inch
- Divergence Power At Cockpit Power
At Cockpit
- Window - 14,000 feet
Window - 1,000 feet
-
- 5degrees 6 billionths of a watt 114
millionths of a watt
- 2degrees 4 millionths of a watt 680
millionths of a watt
- 1degree 14 millionths of a watt
3 thousandths of a watt
- 0.5degrees 61 millionths of a watt 11 thousandths
of a watt
-
- Comment
From Jim Mortellaro
- 12-31-4
-
- And just what did the news media report tonight? The
CBS and NBC news organizations announced that these 'events' were likely
the result of 'kids' able to obtain lasers from catalogs, playing pranks.
-
- Will those who believe this claptrap please stand up?
Thank you for standing up. Now if you all don't mind, allow me to count.
-
- One, two ... uh ... never mind. I haven't got a computer
that big. Oh well, I suppose this one's gonna be believed just like Chemtrails
are jet Contrails. And the check is in the mail. And ... your place or
mine? And ... "If you REALLY loved me you WOULD!"
-
- God bless Amerika...
-
- ...and all the lemmings whose brains are at sea.
-
- Jim
|
