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-   -   Virgin Atlantic flight from London to NY returns after pilot hurt in laser incident (https://www.pprune.org/rumours-news/574720-virgin-atlantic-flight-london-ny-returns-after-pilot-hurt-laser-incident.html)

lederhosen 16th Feb 2016 07:44

Do you have something tangible to back up your last assertion that these are incredibly brief flashes Tourist? I would expect that my experience is fairly typical and I have been hit multiple times. It is difficult to judge how long the exposure to the laser has been. My immediate reaction is to look away. But the events are highly distracting particularly high powered green lasers which I have experienced many times (6-8) in the middle east and the Balkans. On glancing back the laser has still been there, which suggests something other than that which you are saying. Switching off lights also helps, which again indicates that the laser is being actively targetted.

My first concern is to assess if there has been any damage, which takes a moment. As these events (at least the ones I have been aware of) happen at night, it is not always easy to assess whether blurring was there before as a result of tired eyes or due to damage. So far touch wood there does not seem to have been any permanent damage, but I have definitely been aware of some blurred vision the next day. It is reassuring to hear your suggestion that nothing can possibly happen, but some scientific references would be even better.

Airbanda 16th Feb 2016 07:57


Could someone explain the use of the ampersand symbol in the "L" word please?
IIRC it's because if you're seeing the site with ads use of the properly spelled word causes the software to pull up ads for the outfits that supply the lasers!!

dsc810 16th Feb 2016 08:01

@PDR1

For prosecutions - try this......
Three jailed for using laser pens at East Midlands Airport - BBC News

or this.......
http://www.bbc.co.uk/news/uk-england...ngham-29648440

wiggy 16th Feb 2016 08:14


Then consider what an aeroplane at 8,000 feet and a couple of miles distance actually looks like to a ground-based observer. Mostly it's a blob - a grey/black silhouette. How would said observer know that his/her l@ser was even HITTING the aeroplane, let alone the cockpit window? The l@ser target designators which you reference in support of your point have telescopic optics for this, without which (I suggest) these claimed acts of marksmanship are simply impossible for normal humans.
Neverthless despite your beliefs there are multiple officially registered reports (worldwide) of significant distraction or worse being caused by lasers illuminating aircraft, even briefly.

So either

1. You are implying those making the reports on being illuminated by lasers are lying or

2.You are overestimating the level of marksmanship required.

Which is it?



Yesterday people turned on Gouli and tried to bulkly him into silence because (not being an ATPL) he wasn't allowed to have an opinion on a subject which they felt he knew nothing about.
And to be fair it looks their feelings were at least in part correct since Gouli has now said - " I am now much better informed about the decision processes and it makes a lot more sense to me now".



Perhaps its time for those bullies to withdraw their abuse or consider adopting a similar silence on the technical nature of l@ser devices. Who knows, you might actually learn something!
Aiming systems maybe, but don't need any help with the technical side of the Physics, thanks anyway...

Pace 16th Feb 2016 08:29


You were temporarily blinded but not temporarily incapacitated?
Chesty Morgan

I stand corrected! Yes temporarily incapacitated which wasn't a major problem at altitude but would be on the latter stages of the approach.

The vast majority of over the counter laser devices are low powered and should be regulated to even lower power fit for purpose which is usually as pointers in a classroom environment.

There are far more powerful devices available on the internet and these could cause serious damage including damage to the Retina so the government need to regulate these out of use of the general public.
The over the counter variety which are low powered should be regulated to lower power still to a minima for using as a classroom pointer.
These things are not toys to be used by bored kids getting a thrill

A ban on the devices other than the very lowest power is the only way as catching the culprits is almost impossible from a position of a jet travelling at high speed

Pace

Chesty Morgan 16th Feb 2016 08:30

Ok PDR as you're the resident laser expert why don't you tell us what the beam diameter of a typical laser would be at that distance?

Chesty Morgan 16th Feb 2016 08:56

Let me help you out.

A typical beam divergence of a green laser is between 1.2 and 1.5 mRad.

With a beam width of 1mm at 1 foot the beam width at 15000 feet would be approximately 5500mm, or 18 feet.

I think it would be fairly easy to hit a 1 foot target with an 18 foot laser.

Sallyann1234 16th Feb 2016 08:57

PDR


yesterday I challenged someone to provide cites for claims made - a claim that someone had been caught and prosecuted for using a l@ser against an airliner. It shouldn't have been that hard because such an arrest (never mind a prosecution) would have made it into the news.
If you would like to turn to the second page of this forum you will find an ongoing thread about laser attacks and prosecutions of offenders. This alone shows your lack of experience of the subject.

As for the accuracy of laser sighting, no-one has suggested that it is easy to hit an aircraft. That is probably part of the attraction for those who attempt it. The Virgin aircraft in this case was flying a standard departure route from Heathrow, and the laser user may have targeted many aircraft on this and possibly previous days before achieving a hit.

You clearly know a great deal about lasers, but you do not understand their effect on the pilot of an aircraft full of passengers.

wanabee777 16th Feb 2016 09:17

Once the report was made to Flight Control, the decision to continue or RTB was, for the most part, out of the Captain's hands.

lederhosen 16th Feb 2016 09:19

PDR1 it is good to see some numbers and your post triggered a couple of minutes search which found a green laser with a beam diameter of 2x7 mm and a divergence of 2 mRad. Apparently their advertised use is for pointing out stars which would be a bit difficult if they wave around as you suggest. But I imagine that gets a bit slow and aiming at planes might be tempting. The beam diameter therefore at the distances we are talking about seems to be over five meters and my real life rather than theoretical input is that they can definitely hit you.

unworry 16th Feb 2016 09:35

My nephew is an electronics nerd of sorts.

He raised a disturbing point about the recent proliferation of youTube videos detailing:

- how to get the laser diode out of a laptop DVD burner
- how to turn a 5mw laser into a 100mw laser
- and so on.

The vids he showed me each had several million views :eek:

Of course, any one smart enough to do these hacks isnt going to test it out on the nearest jet, right? :ugh:



Go with what you know.
@Wirbelsturm - wise words, sir

Chesty Morgan 16th Feb 2016 10:07

By "damage" do you mean temporary blindness, distraction, light spots or permanent physical damage?

lederhosen 16th Feb 2016 10:12

The one I found in a very short period of time says min 900mW, how does that tie in with your numbers? How low would you have to be and how long an exposure for this to be dangerous in your opinion?

The difference seems to be that Chesty and I have experienced this in real life and it was unpleasant....hopefully nothing more. I would be delighted if what PDR1 is saying is correct and there is no risk. But so far I am not convinced, particularly about the exposure time and the difficulty in aiming, which frankly does not tie in with my experience.

Flying Lawyer 16th Feb 2016 10:21

PDR1
I disagree entirely with your comments about Gouli.


yesterday I challenged someone to provide cites for claims made - a claim that someone had been caught and prosecuted for using a l@ser against an airliner. It shouldn't have been that hard because such an arrest (never mind a prosecution) would have made it into the news. Unless and until I see that cite I will regard many of these claims with a degree of scepticism.
The reason that there are few laser/airliner prosecutions relative to the number of incidents is that, unless the conduct is persistent, it is difficult to trace the perpetrators.

Some prosecutions from the US -

2014, Stephen Bukucs, 6 months prison & 3 years Supervised Release.
Airliners on approach to Portland International.
Admitted 25 incidents over several months.
Arrested after intense air and ground surveillance by FBI agents and police officers.

2013, Adam Gardenhire, 30 months prison.
Corporate jet on approach to Burbank.
Further charge relating to police helicopter which traced him dropped in plea bargain.
(Sentence reduced following a successful appeal on a point of law.)

2012, Glenn Hansen, 6 months prison & $10,000 fine.
Airliners departing Orlando International on at least 23 occasions.

2012, Michael Smith, 2 years prison & 3 years Supervised Release.
Airliner on approach to Omaha and Police helicopter which traced him.


Whether you believe it or not, the use of lasers against aircraft is a serious problem worldwide.


Laser attacks on aeroplanes occur predominantly near airports.
Helicopters (predominantly emergency services) predominantly over cities.


I don't have the latest figures to hand but, in the year ending March 2015, the UK CAA received some 1400 reports - an increase of 3.5% from 2014.

What percentage of those reports do you suggest were false?
ie Made by pilots jumping on the 'bandwagon', as you suggest.

Chesty Morgan 16th Feb 2016 10:28

'E's buggered orf!

PDR1 16th Feb 2016 10:37

Well I posted an analysis with the power density numbers showing that the problem was unlikely to be as significant as suggested, but someone has deleted it. Why?

PDR

Edit: in fact BOTH of my posts analysing the numbers have been deleted. Why??

Chesty Morgan 16th Feb 2016 10:42

Actually all but one of your posts have gone.

lederhosen 16th Feb 2016 10:45

Who knows ....but can you please pm me an answer to my last question PDR1 if this is considered too sensitive by the mods.

Tourist 16th Feb 2016 10:58


Originally Posted by andytug (Post 9271295)
By that logic it would also be impossible to take a photogragh of said aircraft with a high-magnification zoom lens camera handheld.....but that can be done easily also.

No, a high magnification zoom lens has orders of magnitude more "spread" than a laser.

Tourist 16th Feb 2016 11:04

I, like many others who more likely post on the rotary forum have a reasonable amount of experience when it comes to using a hand held laser pointer called an LPL30.

The hand is certainly not steady enough to maintain lock on an aircraft thousands of feet away, even when the beam is visible through NVG.
The idea that a chav could do anything other than catch the aircraft with a momentary flick doesn't hold water.

I am surprised/disappointed that PDR1s posts are being removed, because I don't see anything in them that could possibly help the people shining lasers, and the are factually correct.


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