lasers.

[Dennis Kenyon]

Hallo guys & gals ... you've always been most helpful in the past when I've needed specific info, so can I ask if any pilots on here have actually experienced a laser attack while airborne.

I've been commissioned by the FLYER magazine to write a piece on the subject and would like to include some words from someone with experience. I'd need your permission to quote please.

As always, my deadline for article submission is close - being the 7th August. So H E L P. please.

Regards to all. Dennis Kenyon.

[MightyGem]

Hi Dennis. I was lasered many times as a Police pilot over Liverpool, both red and green. The green ones were the brightest of the two.

My personal view was that they were an annoyance rather than a danger. It was never a straight blast of light into the cockpit, you always saw it waving around as the scrote tried to get it on the aircraft, so avoided looking at it. I was certainly never in danger of losing control.

Obviously, others will have different opinions.

[Dash8driver1312]

Flying turboprops around Europe, I have had a green laser painting my aircraft twice. First time was from around 10 miles out in front on our 1'o'clock, as soon as I saw the twinkle, I called it and stuck my head below the glare shield. Flying IFR on a transition has its benefits. Second time was very close to us on our right side, so again head out of the way with something solid between us and the source. Both times at night.

I'd love me a GAU-12 slaved to a laser receiver to teach these guys a one-time lesson in how funny we think it is.

[G0ULI]

Dennis
There are other threads which have more details of laser attacks and responses by law enforcement to aircraft being lasered.

Bottom line is that these "attacks" have been happening for years and to date not a single aircraft has crashed because it was targetted by a civilian laser pointer.

The military have access to more powerful lasers and technically could down an aircraft, although use of lasers in warfare to cause blindness is supposed to be forbidden under the Geneva Convention. Any laser powerful enough to cut through metal would cause physical injury to a pilot. Apart from experimental proof of concept tests against drone targets, such systems have not been used to date.

Green lasers appear subjectively brighter than other colours because the eye is most responsive (sensitive) to the wavelength of green light.

Any very bright and sharply focused beam of light can cause confusion and disorientation in a darkened cockpit at night. It does not need to be a laser specifically.

It is unlikely that a ground based laser pointer will cause permanent damage to the eyesight of a pilot even if looked at directly. The blink reflex protects the eyes and the power over distance ratio is too low to physically damage retinal cells. A victim looking directly at a particularly bright laser will suffer a period of after images which could last from several minutes to a couple of days.

Direct exposure to 100 mW level laser beams in a laboratory enviornment will cause temporary blindness but the damage is usually restricted to a very few retinal cells because the lens in the eye focusses the beam to a very small point at the back of the eye. A small black spot in the vision field will result, which will generally go unnoticed a short while after recovering from exposure.

Exceptional or repeated exposure can result in multiple sites of retinal damage which will not recover and will increasingly cause a deterioration of vision. Corneal burns can occur, similar to getting sunburn on the surface of the eye. Laser exposure can also lead to the formation of cataracts due to heating damage to the lens of the eye as the laser beam passes through.

These are exceptional injuries and should never happen in a modern optics laboratory as protective eyewear should be worn at all times and safety interlocks and beam blockers and absorbers should be in place except when the laser is actually required. The first lesson all students are taught is never to place any part of their body in the path of laser light, irrespective of the power of the beam.

Being targetted by laser pointer is an uncomfortable experience that is more of an annoyance than a direct physical threat. It has the potential to make a difficult situation more hazardous but as mentioned before, there appears to be no recorded case of civilian aircraft loss or damage anywhere in the world that can be attributed to a laser pointer attack.

The hysteria surrounding this subject is somewhat overblown in my opinion, but many victims of such attacks will violently disagree and given the potential consequences with regard to loss of life and property damage, they may be right to do so.

[Thridle Op Des]

While there have not been any attributable accidents to illumination by laser, I have to disagree with G0ULI especially in the regime of causality in the contemporary safety environment. If you are looking for a 'pilot blinded by laser and crashed' scenario, then as you say, that modality has yet to be experienced. As one of the components of the accident interaction then I would venture that this needs to be addressed. As someone who has experienced a green laser attack while on intercept for an ILS, my physiological reaction was quite interesting. The mental preoccupation with the event as well as the 'scratchy eye' effect I had was very distracting from managing the aircraft trajectory, even as Pilot Monitoring. We reached the stand safely and neither was any paint scratched, underwear changed or death (apart from my images of what I would like to have done to the 'scroat' if armed with a baseball bat), nonetheless as part of the whole safety environment, I would suspect that the idiot on the ground also asked "what could possibly go wrong when I flash this aircraft with my laser pointer".

[hueyracer]

Found this article a while ago…worth reading…

Source:
USAARL Report No. 90-3, Laser Protection with Image Intensifier Night Vision Devices, by David J.Walsch 2 ́1990


Risk analysis - Mission: Laser glare
Worldwide the number of laser incidents grow rapidly.
1In the US i.e., the numbers doubled from 2009 to 2010 to a total of more than 2.800 incidents.
These attacks are usually regarded as dangerous intrusion and require the use of the police, especially police helicopters, to identify the perpetrators.
While on mission, investigating police-helicopters had been targeted by laser-offenders several times. The crews suffered from health impairments, such as teary eyes, disorientation and short time visual impairments, due to flash-blindness.
Because, depending on power and exposure time, lasers can harm eyes permanently, it is necessary to analyse the risks and to look for measurements to minimize these risks.
While doing this, one has to consider the rapid developing of lasers, while legislation, trade restrictions and laser-classification are lagging behind.
2Especially mentioned here is the so called the blink reflex, which was used to specify the older laser-grades. Newer research showed, that only a minority of people showed the „blink reflex“, when blinded by a laser and should no longer been taken into account.
The following impairments and injuries could be caused by lasers.
• Pilots / Crew members could be startled by the sudden, often flashing, laser light – until it can be identified as a laser attack instead of an operational aircraft failure.
• distraction / annoyance from the normal cockpit tasks
• blinding with impairment of the visual perception of instruments and obstacles within the
flight path (i.e. transmission tower)
• 3flash-blindness, from a few seconds up to minutes. At night, due to the wider opend pupils,
flash-blindness tends to occur much more easy and lasts longer. Often combined with
disorientation and the feel of sickness. Continued flight might not be possible for the pilot.
• permanent eye-damage due to burns inside the eye: 4Already relative small power (few
milliwatt) of a wavelength, which is transparent to the eye (around 350 to 1200 nm [green Laser around 523 nm]) can lead to blind spots, cause the parallel laser-beam will be focused by the lens of the eye. Damages will often not be recognized by the person straight away, but will be found by surgery.
(Further dangers, which occur on other wavelength, are not listed here.)
Further factors are:
• the laser-power – more power – more effect / damage
• the divergence of the laser (widening) – the less the divergenz, the higher the risk.
• the wavelength of the lasers (infra-red- ultraviolet-parts of a lasers can ́t be recognized by a
pilot, but can also harm).
• the colour of the lasers (yellow and green laser are recognized brighter than red or blue laser
1 USA – Departement of Transportation, 19.01.2011 - Siehe LaserUSA2010.pdf
2 Aus Wikipedia: Die Bundesanstalt für Arbeitsschutz und Arbeitsmedizin stellt fest, dass unter typischen Laserklasse-2-Bedingungen nur 17% der Probanden mit einem Lidschlussreflex reagierten und somit dieser Reflex als einziger Schutzmechanismus bei Expositionen durch Laserstrahlung dieser Klasse keineswegs ausreicht.[1] In der BGI
(Berufsgenossenschaftliche Information) 832 "Betrieb von Lasereinrichtungen" vom April 2003 heißt es: "Von dem Vorhandensein des Lidschlussreflexes zum Schutz der Augen darf in der Regel nicht ausgegangen werden. Daher sollte man, falls Laserstrahlung der Klasse 2 ins Auge trifft, bewusst die Augen schließen oder sich sofort abwenden". Die Lidschlussreflexzeit ist von zahlreichen Einflüssen abhängig, u. a. von der Größe des Lichtfleckes auf der Netzhaut. Die Unfallverhütungsvorschrift (UVV) "Laserstrahlung" BGV B 2 geht hingegen noch von einem Lidschlussreflex nach 250ms aus und steht damit neuen Erkenntnissen aus der Forschung entgegen.
3 Flash blindness - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Flash_blindness) 4 Laser ? Wikipedia (http://de.wikipedia.org/wiki/Laser)

with the same power)
• pulsating or constant beam - with a pulsating laser more energy will be transmitted in a short
time and increases the risk of eye-damage
• movement and speed of the aircraft – has influences on targeting the aircraft
• the distance to the aircraft
• the angle in relation to the cockpit
• the flight-phase (start/landing/cruise)
• the pilot-estimation / - reaction
• optical parts, like i.e. binoculars and or glasses, which will focus the laser additional
Laser-grades, 5Classified according to EN 60825-1
Due to threats to the humans, lasers are listed in grades. It ́s done by the manufacturer. (The old grades according to DIN VDE 0837 are not longer valid for new lasers)
Grade Power Wavelength
Description
The laser isn ́t harmful or the laser is in a closed case/box
The laser isn ́t harmful, if no optical lenses, like magnifying glasses, are used
The laser-beam is only in the visible lightarea (400 nm bis 700 nm). It isn ́t harmful, if the exposure-time for the eye is under 0,25 s.
As grade 2, as long, as no optical lenses are used to view the beam
1 1M
2 2M
< 25 μW < 25 μW
≤ 1mW ≤ 1 mW
400... 700 nm
302,5... 4000 nm
400... 700 nm
400... 700 nm
3R 1 bis 5 302,5 nm... The laser is dangerous for the eye mW 106 nm
3B
5 bis 302,5... The laser ist dangerous for the eye and in some cases also for the 500 mW 106 nm skin. Stray-light isn ́t dangerous in most cases.
> 500mW 302,5... The laser-power is very dangerous for the eye and dangerous for 106 nm the skin. Even stray-light is dangerous for the eye and for the skin.
For the blinding of aircraft the offenders normally use lasers grade 3R and 3B. You can easily buy them in the worlds wide web.
To have some facts and not only theoretical views, a green laser was ordered in China.
For € 17.74 and € 1.54 postage/package a „30mW super-bright green Laser-Pointer with Li- Ionen-Akku (tra416)“ was bought.
After four weeks it arrived.
It had to be collected at customs – but it was no problem to get it!
First trials showed, that the power of the beam dropped after a short time (visible beam reduced in brightness). It was thought, that it was due to the akku, so a bigger power-source was installed to have the full power through all the tests.
The tests showed, that it was powerful enough to burst a balloon after a few seconds, which was placed about 50 cm away from the laser.
At a distance of about 60 meters the laser-beam was widened to an area of about 6 x 9 cm. 5 Laser ? Wikipedia (http://de.wikipedia.org/wiki/Laser)
4

Calculating with a straight factor that would mean, you would have a light-spot from around 1 meter at 1000 meters distance and a 2 meter spot at 2000 meters.
Additional findings were, that the laser didn ́t fit the safety standards. It wasn ́t label d at all and it strayed infra-red light.
To prevent risk or damage while doing a set of tests, the appropriate authorities were informed. (tower, ground-handling, airport-safety, fire-brigade, police and ATC.
After closing of the airport, a BK117 was parked on a taxiway in vicinity of the runway, facing north.
A small video-camera was set up and the helicopter lasered from the runway from different distances (measured by GPS)
Later a video-camera was set up on the pilots seat, (eye high) and further tests done.
In the video it can be seen, that the laser is coming in shaky, cause you can ́t hold the laser rock steady. So it ́s producing a lot of flashes instead of a steady blinding.
NM km Hitting diameter around stillshots of the video
0,32
0,59
100 cm
0,46
0,85
150 cm
0,82
1,52
200 cm

1
1,85
240 cm
1,18
2,19
300 cm
Calculations were made for power on the eye on an area of 0,3 cm and 0,5 cm and because you can buy stronger laser in the web and you don ́t know, what laser is used, also for lasers with 100 mW, 200 mW and 500 mW.
Calculations were made by pretending, that all lasers would widen up their beam the same way the tested laser-beam did. Videos in the internet show, that that isn ́t always to be expected, cause there are „better“ lasers around.
That would mean, even more power on the eye.
There were no calculations for pulsed lasers.
From inside the cockpit

Entfernung m Durchmesser cm 0 0,3 607 100 10 500 50
Kreisfläche cm r2*π 0,4712289 10,995341 15,70763 78,53815 157,0763 314,1526
Kreisfläche cm r2*π 0,4712289 10,995341 15,70763 78,53815 157,0763 314,1526
Kreisfläche cm r2*π 0,4712289 10,995341 15,70763 78,53815 157,0763 314,1526
Kreisfläche cm r2*π 0,4712289 10,995341 15,70763 78,53815 157,0763 314,1526
Leistung mW bei 0,3cm Ø
10,0000
0,4286 0,3000 0,0600 0,0300 0,0150
Leistung mW bei 0,3cm Ø
30,0000
1,2857 0,9000 0,1800 0,0900 0,0450
Leistung mW bei 0,3cm Ø
100,0000
4,2857 3,0000 0,6000 0,3000 0,1500
Leistung mW bei 0,3cm Ø
500,0000
21,4286 15,0000 3,0000 1,5000 0,7500
Leistung mW bei 0,5cm Ø
10,0000
0,4547 0,3183 0,0637 0,0318 0,0159
Leistung mW bei 0,5cm Ø
30,0000
1,3642 0,9549 0,1910 0,0955 0,0477
Leistung mW bei 0,5cm Ø
100,0000
4,5474 3,1832 0,6366 0,3183 0,1592
Leistung mW bei 0,5cm Ø
500,0000
22,7369 15,9158 3,1832 1,5916 0,7958
1000 2000
Entfernung m 0 60 100 500 1000 2000
Entfernung m 0 60 100 500 1000 2000
Entfernung m 0 60 100 500 1000 2000
100 200
Durchmesser cm 0,3 7 10 50 100 200
Durchmesser cm 0,3 7 10 50 100 200
Durchmesser cm 0,3 7 10 50 100 200
Due to an expert report in an court trial, the exposure limit is t=0,25 sec for a wavelength of 532nm and 5 mW power.
Additional wavelength (i.e. infra-red) have to be considered and shorten the time.
Regarding the calculations and findings (flashing hits, widening of the beam) you can assume, that your eyes are more or less safe, if you are at least 1 km away from the attacking laser and you are only hit in a „flashing manner“
Flash-blindness, which may impair a pilot in a way, which may inhibit his possibilities to fly the aircraft are not only possible but even on greater distances – probable.
(From authors experience)
According to Pythagoras (a2+b2=c2), at a height of around ~ 2300 feet – height being equal to distance to the laser on the ground, with normal lasers used and only flashing hits, your eyes are fairly safe.
If you don ́t use laser-protection-goggles, you better fly around 2500 feet or higher, if you expect a laser blinding.
While doing the tests, it was also found, that NVG aren ́t very useful to search for an offender, cause green light isn ́t amplified and it is hard to identify the laser between other city lights.
The laser-beam, which often can be seen with the naked eye, won ́t be seen with the NVG.
Both pictures were made at the same position, on the left you can see the beam, on the right, with NVG, you only see the light-source, not the beam.
If you expect laser blinding, you should be prepared to ensure the safe operation of the aircraft. You could use the autopilot, if fitted, or have the copilot ready (also if fitted ;-))
Switching of all lights may also be an option, to reduce the risk of further laser-hits, but has to be coordinated with ATC – may be in advance.
In this context there are some words necessary regarding NVG.
Even so, due to their design, they won ́t let a laser through and therefore give a certain amount of protection, this protection is only given for a direct hit.
Because pilots need to check the instruments, the NVG aren ́t directly in front of the eye – they are at a certain distance, so that a pilot can look underneath them.
If the pilot isn ́t looking straight through the NVG or is hit from an angle, a laser can hit the eye and permanent damage can occur!
„6With normal scanning movements critical areas of the eye are exposed to possible laser-damage. Throughout protection requires ... mechanical cover or laser-protection-glasses or visors, which cover at least 90°.“
If you get hit by a laser while flying lower than 2500 feet and you can ́t get hold of the laser, to get information about it ́s properties, you should see the doc to check your eyes.
FLY SAFE!
ISO 6161:1981-02
Individueller Augenschutz; Filter und Augenschutz gegen Laserstrahlung
DIN EN 207:1998-12
Persönlicher Augenschutz - Filter und Augenschutzgeräte gegen Laserstrahlung (Laserschutzbrillen); Deutsche Fassung EN 207:1998
DIN EN 208:1998-12
Persönlicher Augenschutz - Augenschutzgeräte für Justierarbeiten an Lasern und Laseraufbauten (Laser-Justierbrillen); Deutsche Fassung EN 208:1998
6 USAARL Report No. 90-3, Laser Protection with Image Intensifier Night Vision Devices, by David J.Walsch 2 ́1990

[Peter-RB]

Hi Dennis,

Tell the readers to avoid Burnley After Dark, the Bro's and Bloods there use lasers just to show their pals they've got one, and "look how far it goes"

Peter R-B
Lancashire

[ThirtyKnotHeadwind]

A clear night with not a cloud in the sky and a full moon in N.Ireland, was about to turn finals for a private landing site in my R22 when i got targeted by a green laser from my 12'O'clock.

Gave me a real good going over with it and had even managed to get it into the cabin just beside my head before I turned to my right.

Was shone from a housing estate but didnt report the incident.

[206 jock]

I live almost on the Meridian line about 35 miles north of Greenwich. I was recently flying at dusk and was surprised by the effect of the laser The Greenwich Meridian - where east meets west: Meridian Laser (http://www.thegreenwichmeridian.org/tgm/articles.php?article=14) even at that distance

[Dennis Kenyon]

Wow ...why didn't I approach you guys sooner. T'would have saved me more than a few hours of internet research work.

So for Mighty Gem, Dash 8, Gouli, PeterB, the Dubai input, 30 knots and 206 Jock .. a big thanks. I plan to include quite a few references from your notes but will not name, names. Closing is 7th August now but the article is scheduled for the November issue of FLYER.

I never ceased to be amazed at the breadth of experiences on this site and the willingness of you guys/gals to share them. Another big thanks to you all.

Oh and I know I've said it too many times, but at age 82 even still holding a Class One, this is to be my final flying year, although I am booked to display Enstrom's 480 at the Higveld - Waterkloof AFB in September. But definitely my swan song chaps.

Great flying to all. Dennis Kenyon.

[Dennis Kenyon]

...... and OH - I'm still trying to digest the Huey Racer input. Thanks. DRK

[Ian Corrigible]

While I prefer Dash8driver1312's 'proactive' solution, the fixed-wing OEMs are already working on a potential passive solution in terms of läser-filtering appliqué films: Airbus partners with Lamda Guard to evaluate läser strike protection (http://www.airbus.com/newsevents/news-events-single/detail/airbus-partners-with-lamda-guard-to-evaluate-an-innovative-laser-strike-protection/).

I/C

[Devil 49]

Never had a head on encounter, always low lateral, red or green. The cabin is illuminated with red or green, that flashes once or twice as tracking is corrected, then fairly steady until I turn away putting fuselage between us.

What makes me nervous is the availability of higher powered pointers: 1 and 2 watts- check wickedlasers.com.

[G0ULI]

Devil 49
Every household with a DVD writer in their computer or a Blueray player/writer has access to a 1+ watt laser inside the mechanism, so there are potentially millions of them out there. That is more scary than spending hundreds of dollars buying something from an internet site. Bans and import controls simply won't work because these devices are in general circulation and just need to be repurposed with a little technical know how.

[JulieAndrews]

One of our cabs was targeted and no harm done - went to area of source following day to spread the word that it's quite a serious offence but probably just holiday makers messing about - not knowing possible consequences.
There are various sources on tinterweb for post-strike actions - BALPA site has a link...........

[Dennis Kenyon]

Just to add a couple more facts picked up from the net today.

Apparently the US Government have invested close to $1.2 Billion in the Livermore National Laboratory for research. So far the facility has produced a laser beam 60 times more powerful than anything else in the world and can generate temperatures up to 100,000,000 degrees. I suppose that is Fahrenheit but at those numbers, who really cares! DRK

[hihover]

Dennis,

I have been lasered several times and I have to say that my natural defence mechanism kicks in every time and I simply look away, no need to even move your head or put something solid between the laser and yourself, just look away. I believe it is something that we will have to learn to live with for as long as lasers are available on the open market.

Of course, the "drama queen" factor will always make these "attacks" sound perilous, but the reality is, as described above, they are just annoying.

Funnily enough, on my last incident, I was on patrol here in the Middle East and had a live downlink to the local comms centre (Police). Someone shone a laser at us from an easily identifiable location and the comms centre saw it and immediately sent police around. Someone was arrested within minutes. I don't know what happened to him after that.

I may still have some footage of it if you are interested.

Take care my friend.

Tam

[Ian Corrigible]

Just to add a couple more facts picked up from the net today.
And U.S. Navy rotorcraft (Osprey?) will soon be able to respond in kind to being lased:

High Energy Fiber Läser (https://www.fbo.gov/index?s=opportunity&mode=form&id=ad00d18d0b5f0387a657af6b8dafcebd&tab=core&tabmode=list&=)
Under this effort the contractor will develop and demonstrate prototype High Energy Läser Weapons System (HELWS) subsystems, which will be integrated together and installed in a rotary-winged aircraft for a series of airborne läser weapon demonstrations.

The läser pointer in this case being a 25kW system (http://www.onr.navy.mil/en/Media-Center/Fact-Sheets/High-Energy-Fiber-Laser-System.aspx).

I/C

[vortexadminman]

I concur with what Mighty Gem said. Having done it a while and been zapped a few times. I do know that the best defence is offence.A BIG shiny torch back on their house/car generally stops it.

[Dennis Kenyon]

Further thanks to all for the contributions and especially to Ian C for the notes on the High Energy Laser information. I missed the closing date for publication for the latest info but the piece will appear in the October issue of FLYER.

And guys/gals reading this ... can you also refer to my new thread on a team to tackle the Freestyle section of the WHC to be held in Poland August 2015. Also likely members to join an MD/Hughes 500 club with a possible Sikorsky 300 sub section ... just expression of interest at this stage. PM me for details. Best wishes to all rotary flyers. Dennis K.

[Buttocknurdler]

Hey Dennis, is this the rebirth of the Hughes 500 Club? I was a member in 1994 at Redhill (G-HSOO).

[Dennis Kenyon]

Thanks for the mails guys.... Yes the idea is to run a closed membership helicopter club based around an MD500 C-20 model. At this stage, we are looking for levels of interest only. Precise figures have not been decided but in round terms, we expect to be thinking in terms of a £20 to 25k membership fee which would buy around 40 to 50 hours per annum with an arrangement to increase hours for an extra premium. None of this is set in rock yet and all subject to the right level of interest and calculation of likely operating costs. The club membership would cover ALL operating costs and would be a non profit organisation and hopefully with progressively reducing costs after initial set up. Regards to all. Dennis Kenyon.