Arrest made after laser attack on pilot

[motzartmerv]

Go rick...Yep i agree..why would you..??..if anyone doubts the dangers involved, go and point a laser at a 200 tonne jet doing 200 miles an hour 200 feet oiff the ground, carrying your wife and kids on board...

 

 

[BLA82]

I know I am coming in at the end of this conversation but I have somthing I wish to add.

 

basscheffers you alarm me to think you are a fellow pilot and yet you are trying to play this down.

 

I agree with Rick-P's comment and that of motzartmerv. My father is an airline pilot and I have heard first hand how distracting it is. I believe it is an attack, it's an attack on peoples safety and quite frankly your comments seem to be that of what a un dissaplined ttens parents would be when they try and say their kids did nothing wrong.

 

We all have done stupid things in our time but with the amount of media coverage this gets I believe anyone who does it needs to be jailed, if not for aircraft safety but for that of their own as they don't seem to take in whats around them:thumb_up:

 

 

[Guest basscheffers]

I know I am coming in at the end of this conversation but I have somthing I wish to add.basscheffers you alarm me to think you are a fellow pilot and yet you are trying to play this down.

If I am playing this down, then why did these guys experience no ill effects when doing actual flight testing: http://www.equipped.org/lasers_airliners.htm ?

 

And why are they incorporating the same type of lasers in distress beacons now to signal aircraft?

 

And why is the FAA considering warning aircraft of entering restricted airspace using these lasers?

 

Sorry, if you think this is more than a simple annoyance, you simply do not understand the physics or the facts.

 

 

[Admin]

Careful Guys :big_grin: - it's all fun here!

 

 

[BLA82]

Simple annoyance,

 

A simple annoyance whilst driving a car ie a mobile ringing or music to loud can lead to a serious motor accident so a simple annoyance to a 747 on final with 300 pob and how ever much fuel = you do the maths.

 

I hope this practise never leads to a serious accident because it will make those over payed uni lecturers like the ones that did that study look like fools.

 

 

[Ross]

There are plenty of ground based lasers used to control earthmoving equipment, control mining excavations, pipe laying etc. They could be used as fixed pointing beams or used with rotating beams forming a reference plane.

 

In the case of "land forming" for irrigation farms these are usually 5 milliwatt red rotating lazers mounted on towers about 5 metres above the ground. They usually have warning signs on them to warn against staring into the transmitter.

 

The ones I have seen in the past worked fairly accurately out to 300 metre radius and sometimes effectively out to about 4 or 500 metres radius from the transmitter depending on conditions. The beam is detected by a receiver mounted on a mast that can be extended a similar distance above the working surface or retracted to a shorter length when constructing an embankment like an elevated bank or a roadway. To excavate more depth the the mast on the excavator would be extended so that it could reach the beam as the hole got deeper.

 

It made a great deal of difference to these transmitters or rather the quality of the lase beam if the transmitter could be mounted on a tower so that all erratic movement of the tower (and beam) was damped out when set up and working. This is not all that easy to do.

 

Because of the normal scattering that a laser beam usually encounters due to the air it encounters and the dust and possible other particles in the air the beam starts to diverge and looses its energy concentration and its ability to trigger the receiver electronics.

 

In these instruments I think the starting diameter was about 15 mm but uses a lens to make it come down a cone which has already opened up again to something like 12 mm at around 300 metres radius from the transmitter.

 

But at that distance there is already a significant loss of power even though the beam is still only about 12 mm diameter.

 

As you get out further the scattering of the beam by the gunk in the air makes the beam diverge more and more. The effective work done by the reducing power applied on any target in this situation gets less and less.

 

This work done by whatever power is left in the beam is further reduced as the radius increases because the time the beam is on any particular target gets less as the radius increases provided that it is a rotating laser, typically 300 RPM or 600 RPM with one I was familiar with.

 

Of course a non rotating beam from a pointer is an entirly different matter.

 

You could often see flashes from these rotating transmitters from public roads at night while driving in irrigation farming areas from some kilometres away from the transmitter.

 

They appear as unexpectantly bright flashes that your brain tells you that you do not want to continue staring at the source. So they are hardly likely to be prevalent enough to be a real nuisance or distraction.

 

I guess this is because a lazer beam is not a constant beam of energy. It is a bit like being hit by a hammer say once every 24 hours verses being pushed by a butterfly for 24 hours straight. But the pulses are so fast that our brains would probably interpret them as a constant beam of very bright light.

 

Either item might be applying the same total amount of energy on you per day or per hour but possibly you might only notice one of them.

 

Due to the angles of the plane the beam is usually set at, the maximum allowed power of the laser (usually 5 milliwatt), the natural divergence and diffraction of the beam, the curvature of the earth and the height and size of the beam it may never be a problem.

 

Please excuse my rambling. It's a bit past bedtime I just noticed..