Thomas Cook cracked Windshield A320 - Full emergency at BRS 9/2/09

[Hostie89]

I was on the ground when a TCX A320 came into BRS declaring a full emergency (i think) We heard on the radio that it had a cracked windshield....Any ideas as to what happened and was everyone ok?

I'd imagine that would imply a rapid/explosive decompression?
Sorry for all the questions! I'm just curious to see if everything is/was ok!
It did land safely though! :ok:

Hostie

[Checkboard]

Airliner windshields are made from composite layers of glass and acrylic (plastic). Generally one of the glass inner layers shatters, which makes it difficult to see anything through the window, but it stays in place and the pressurisation stress is maintained by the acrylic layer. No depresurisation, no emergency.

[aviatordom]

Bird probably hit the windshield. Usually not a serious emergency, but i think that the problems really start if the crack develops into the 2nd layer of glass

[JW411]

I have had several windscreens crack in my flying career and absolutely none of them were caused by birds.

Neither have any of them occasioned a "full emergency" (whatever that might be).

Nor would I imagine that a rapid decompression was caused. It would simply mean that the remainder of the flight would be completed at a lower altitude in order to reduce the DP.

[Smilin_Ed]

I had one shatter due to failure of the temperature regulator in the heater circuit. Temp got too hot and the whole thing shattered. Couldn't see a thing through it but it stayed structurally intact. :uhoh:

[Rainboe]

Sorry aviatordom, but from the benefit of your 14 years of life, you were way out of line there. Windscreens invariably fail spontaneously, only one layer goes, no depressurisation, absolutely no emergency, and no birdies deceased! Can't think of any incident where a cracked windscreen has spread into another layer either! Good to be interested, but those that don't know are better off not answering queries!

[NigelOnDraft]

declaring a full emergency As Flt Crew, we do not tend to declare "full" or "partial" emergencies, rather either "No" to declaring an Emergency, or Pan or Mayday...

I am led to believe that a "Full Emergency" might be an ATC term...

As stated above, a "cracked windscreen" from the Flt Crew / safety point of view is usually a non-event, but might require an airborne return.

NoD

[Ranger 1]

Cracked windscreen and return?
Seen three occurences like this in the past few years, all aircraft returned safely no major crisis.
All aircraft were different types (146, DH-8, Saab 2000), and if I had been at work today, this would have made number four!
:ok:

[WindSheer]

BRS is CAT111 so assume the landing wasn't really an issue, given that the other screen was probably intact.

[NigelOnDraft]

BRS is CAT111 so assume the landing wasn't really an issueI would doubt, unless really necessary, either the Flt Crew or ATC wanting to go through the hassle of setting up / enforcing LVPs for a cracked windscreen ;)

NoD

[Rainboe]

but in this case IF the windshield did shatter and the pilots lost control, it would then be an emergency!
A windscreen on one side probably crazed over when a layer cracked. It is insulated from at least one more layer from another load bearing layer, happy to carry full load itself. Unknown for both, or more, layers to 'shatter'. So, the windows on one side had restricted vision- good idea not to continue. Absolutely not an emergency, and no implications for a more serious failure. It is a frequent occurence, and happens because of the stresses in manufacture, and in electrical heating. These things are not like car windscreens, and cost horribly too. Not a problem.

Why would the pilots lose control? Are you talking.....about......their...er........bowels? Why?

[Ranger 1]

I was under the impression laminated windshields are designed not to shatter into pieces but retain their shape and strength to a degree, unlike the old toughened windscreens they used to use in cars.
Any Autoglass expert out there!:}

[Rainboe]

Autoglass know nothing about these babies! There are usually about 5 layers, 2 or 3 of which are full load bearing, the remainder plastic. They have all sorts of weird treatment in manufacture, and looking through them with polaroid glasses is a totally surreal experience. They are usually at leaast 2 inches thick (alright then.....5 cms), sometimes more. I have never heard of total failure. Even that awful image of the Pan Am nose lying in the Lockerbie field- the windscreen was still complete and unbroken. The windscreen is far, far stronger than the fuselage. If a large bird is going to hit the plane, I would rather it impaled itself on the windscreen and not the fuselage. Stop freaking folks- it is a common occurence! And this is a Professional Pilots website- if you want hysteria, go where the professional pilots are not!

[ABO944]

How about this then ...

Getting both windscreens full of sea spray, which then dried - our view totally obscured and then flying an extra 20 minutes to go through the only cloud in Scotland so we could see slightly better!

All in a turboprop with none of this fancy autoland business :eek:

[eastern wiseguy]

[QUOTE]the only cloud in Scotland[QUOTE]


yea right.......:p:p:p

[telster]

I used to work for the ambulance service and "full emergency" was a term we were familiar with from ATC when attending aircraft incidents, as opposed to "aircraft accident" or "aircraft accident imminent" or "local standby" etc. Obviously most other pprune members would know whether its a term more widely recognised in the aviation industry, but it certainly is used in the emergency services. (In the UK)

[DC-ATE]

Rainboe (http://www.pprune.org/members/104343-rainboe)
The windscreen is far, far stronger than the fuselage. If a large bird is going to hit the plane, I would rather it impaled itself on the windscreen and not the fuselage.

That might be true now with heated glass and all but it wasn't true in the DC-3 days! I know of at least one fatality caused by.....you guessed it.....a darned Canada goose!

[Rainboe]

I think the DC3 had 8mm glass windscreens. But it flew so slow, are you sure the goose didn't strike the DC3 and come in through the tail from behind?

I got struck by the world's most stupid pigeon. After landing and taxiing back towards the apron at Gatwick, I saw it flying straight at me from the side, and thump into the fuselage under the pilots window. Quite some feat- fly into a 737! I think pigeons must have their own version of the Darwin Awards. I have to confess I was too embarrassed to put a 'bird strike on the ground' entry into the Tech Log.

[DC-ATE]

I think the DC3 had 8mm glass windscreens. But it flew so slow, are you sure the goose didn't strike the DC3 and come in through the tail from behind?


Nope.....right through the right front windshield. Killed the Co-Pilot on a North Central (Wisconsin Central) DC-3. Don't ask me dates/times/places, as I don't know. Sometime in the early 50's probably as I heard about it when I first started out at their Base.

[mikehammer]

But it flew so slow, are you sure the goose didn't strike the DC3 and come in through the tail from behind?


The old ones are the best init?

http://www.barryboys.co.uk/phpBB2/images/smiles/beat_deadhorse.gif

[Loki]

JW411

If ATC initiate a "Full Emergency", it means the outside services are deployed in addition to the airfield services. They often turn up just after it`s all over, having made a full "blues and twos" dash to the airfield.

[repariit]

Many windows fail due to failure of the Window Heat Control box. Previous posters have correctly stated that this is not an emergency circumstance by itself. However, if you are sitting behind one, remember that window heat is required to keep a bird from penetrating it.

[Smilin_Ed]

My experience with the crazed, but otherwise intact, windshield was over 40 years ago, but I seem to recall that we had a reduced speed limit if the windshield heat was not working properly. Aircraft was a P-3A. Lockheed was very specific about the reduced windshield strength without heat.

[Lemurian]

The only possible cause for a return would be arcing, uncontrolled or controlled late.
A shattered layer is no cause for a return, even less for an emergency...But I haven't probably thought of every eventuality.

[Ballymoss]

Seen three occurences like this in the past few years, both aircraft returned safely no major crisis.


What happened to number three? Sorry, noone else picked you up on that yet and having read the whole thread, I'm bored.....

Rgds
The Moss:ok:

[cluckingbell]

The only possible cause for a return would be arcing, uncontrolled or controlled late.
A shattered layer is no cause for a return, even less for an emergency...But I haven't probably thought of every eventuality.

Did you think of checking the QRH?

[Lemurian]

cluckingbell
Did you think of checking the QRH?
As I am at the origin of that QRH insertion, that's the reason why I phrased the sentence in the way you saw.

[Conan The Barber]

2 pages due to a cracked windshield. This is coming ever closer to being the Daily Mail.

remember that window heat is required to keep a bird from penetrating it. No it is not.

[Flintstone]

It helps though.

[BYALPHAINDIA]

http://www.barryboys.co.uk/phpBB2/images/smiles/beat_deadhorse.gif


'Oh no it's a 'Non starter' today!!

Good image - Mike Hammer.

Seriously, I can see another episode of TCX Mayday V Pan coming up soon!!

[Springer1]

It seems to me the A320/319 has an inordinate amount of windshield failures. I have had two in one year and when checking with maintenance, there was a history of 11 in a three month period.

Never experienced it in the B727 or DC10.

[glhcarl]

Typical forward flight station window is made up of six (6) layers.

Starting from the outside these layers are:

1] Glass faceplate.

2] Window heat film.

3] Layer of Polyvinyl Butyral (PVB).

4] Layer of Stretched Acrylic.

5] Second layer of PVB.

6] Second layer of Stretched Acrylic.

The outer glass layer is non-structural but provides an abrasion resistant surface for the wipers and a surface for attaching the window heat film.

[bubbers44]

I have had two cracked windshields flying airliners, both were non events. The checklist for outer pane is usually no restrictions, 250 knots below 10.000 ft. One time the window heat was arcing across the windshield at night so turned it off. It is not an emergency at all.

[slatch]

Well, I understand the engineering required for an aircraft windshield but, unless you have been sitting behind one at Fl410 over the Pacific at night and had a failure you can't even begin to understand how it feels. At least in the C141 the windshield Pops loudly and the heating circut arcs and lights up the cockpit. Not a very reasuriing experiance, even though I will admit the windshied did not yield. But since we had no pasengers we did raise the cabin abit to make us fell like we did somehing to help keep it from failing. It did not help that it was only a few months after a friend had this experiance in a CV580......

NTSB Identification: DEN84FA021 .
The docket is stored on NTSB microfiche number 22647.
Scheduled 14 CFR operation of REPUBLIC AIRLINES (D.B.A. operation of REPUBLIC AIRLINES )
Accident occurred Sunday, November 06, 1983 in SIOUX FALLS, SD
Aircraft: CONVAIR 580, registration: N7517U
Injuries: 1 Serious, 1 Minor, 33 Uninjured.
THE ACFT COLLIDED WITH A BIRD DURING THE LANDING APPROACH AT NIGHT. THE CAPTAIN WHO WAS FLYING THE ACFT WAS STRUCK IN THE FACE BY THE BIRD AND FLYING GLASS. THE CO-PLT COMPLETED THE LANDING DUE TO INCAPACITATION OF THE CAPT. INVESTIGATIONREVEALED THE WINDSHIELD HAD BEEN PENETRATED BY A TWO POUND BIRD. CERTIFICATION REQUIREMENTS SPECIFY THAT THE WINDSHIELD WITHSTAND, WITHOUT PENETRATION, THE IMPACT OF A FOUR POUND BIRD AT CRUISE SPEED. THE ACFT WAS MOVING AT ABOUT 190 KTS AT THE TIME OF THE IMPACT. THE LANDING WAS COMPLETED BY THE CO-PLT WITHOUT FURTHER INCIDENT.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
OBJECT..BIRD(S)

Contributing Factors
LIGHT CONDITION..DARK NIGHT

[finncapt]

ABO944

And at what height were you between Sumburgh and Kirkwall?

Great days when you could get seaspray on the windscreen - probably frowned on now!!

The worst thing about cracked windscreens, in my opinion, is the noise when it happens.

[Ranger 1]

Ballymoss;
Well spotted:D,
If my memory serves me correctly two of the three were due to windscreen heat issues as covered by repariit in his earlier post.
:ok:

[411A]

Middle of the night, over central Africa...it sounded like a rifle shot, the outer layer of glass shattered, First Officer ducked, then had a look with his flashlight, not a pretty sight.
Did we have to descend, slow down, or reduce differential pressure?
No.
glhcarl very aptly described the windshield construction on the Lockheed 1011, it is very tough, nicely curved (and optically correct)...and rather expensive.
Ordered up a new unit via Stockholm Radio HF phone patch, and it was waiting for us upon arrival.
It took exactly 2.5 hours to change.

I was told long ago that the L1011 windshield could withstand the impact of a .38 caliber bullet, fired at a distance of four feet, without penatration.
Perhaps glhcarl could confirm, as he is very knowledgeable about the L1011.

PS:
No 'full emergency' (whatever that is) required, just switched off the window heat and pressed on.
End of drama....:}

[four_two]

It seems to me the A320/319 has an inordinate amount of windshield failures. I have had two in one year and when checking with maintenance, there was a history of 11 in a three month period.

Never experienced it in the B727 or DC10.

A somewhat all embracing statement.

My airline had aircraft of both Boeing and Airbus types. Windscreen changes came up with monotonous regularity on all types.

[glhcarl]

I was told long ago that the L1011 windshield could withstand the impact of a .38 caliber bullet, fired at a distance of four feet, without penatration.
Perhaps glhcarl could confirm, as he is very knowledgeable about the L1011

I never heard of the L-1011 windshield stopping a .38 bullet. However, the windshield is over at 2.00" thick and the streached acraylic is really tough.

The windshields were tested by firing a four pound bird (chicken) from a compressed air canon at 350 knots. Thirteen tests were run, the only damage was cracking of the outer glass of the main windshield. The side windows, which do not have the outer layer of glass, suffered no damage.

[forget]

Here's a section from a Lear windscreen. (The things you find lying around ... :bored:)


http://i21.photobucket.com/albums/b270/cumpas/LEAR.jpg

[Rainboe]

Jesus that thing hit one ugly looking bug!

[glhcarl]

Here's a section from a Lear windscreen. (The things you find lying around ... http://static.pprune.org/images/smilies/wbored.gif)


So could you get your .38 and take it and that section of Lear Jet windshield to your backyard and prove if the windshield will stop the bullet?

[forget]

So could you get your .38.....

No. I'm in England. A 38 here is a bra size.

[411A]

Now that I think about it, the .38 bullet trick was actually tried on an old 1011 windshield, by a pilot in 'round about 1980, who was going through TriStar school at Palmdale...they took it out in the desrt and had target practise, so the story went, and a .38 would not penatrate, nor would a standard .45.
A .357 magnum, on the other hand, did.

The old NESA windshields in piston transports were a different kettle of fish, altogether.
These were two layers of glass, with an acrylic core, needed heat for strength and, if they did crack, would sometimes buldge outward, due to pressurisation....never mind the lightning show, from the arcing/burning...not nice, at all.:ooh:

[jetsetjobbie]

A .357 magnum, on the other hand, did

Is that after being weakened by the .38 and .45?:}

You feeling lucky punk?

JsJ

[Level 400]

Had a birdstrike (we think) break the starboard side window at night last year in an RA390 coming out of Norway. Didn't notice it at first just heard a light thump at about 2000' but later on levelling at FL270 we noticed the outer glass layer was crazed. We carried on to destination pressurised and with the windshield heat on low, as normal. No problems and screen took the 7 diff OK. The engineers didn't want us to fly it back even unpressurised as they were afraid the glass may start to delaminate and go through the starboard engine which would get (even more) expensive.

It seems the other layers are mighty strong, even with the outer one broken. :ok:
If I knew how to attach a pic of it to this, I would ! Help? ...:confused:
Level 400

[Dr Illitout]

Do you mean one of these?....

http://i101.photobucket.com/albums/m63/Cking507/01022008199-1.jpg

I know it's a 737 one but they are nearly the same.

Rgds Dr I

[MrFire]

The windshields were tested by firing a four pound bird (chicken) from a compressed air canon at 350 knots. Thirteen tests were run, the only damage was cracking of the outer glass of the main windshield. The side windows, which do not have the outer layer of glass, suffered no damage.

Someone's going to post this so I thought I might as well get in there...

Scientists at NASA have developed a gun for the purpose of launching dead chickens. It is used to shoot a dead chicken at the windshield of airline jet, military jet, or the space shuttle, at that vehicle's maximum traveling velocity. The idea being, that it would simulate the frequent incidents of collisions with airborne fowl, and therefore determine if the windshields are strong enough to endure high-speed bird strikes.

British engineers, upon hearing of the gun, were eager to test it on the windshields of their new high-speed trains. However, upon firing the gun, the engineers watched in shock as the chicken shattered the windshield, smashed through the control console, snapped the engineer's backrest in two, and embedded itself into the back wall of the cabin.

Horrified and puzzled, the engineers sent NASA the results of the experiment, along with the designs of the windshield, and asked the NASA engineers for any suggestions.
NASA reviewed the test data thoroughly and made a single recommendation:












Defrost the chicken.

[repariit]

Previous posts have talked about bullets, bird tests, and Canada Geese. I thought it would be interesting to put them in the perspective of energy impacting the windscreen.

E = 1/2mV^2
A 38 cal bullet weighing 7.1 grams at 300 m/s = 319K joules.
A typical test bird weighing 4 lbs (1814 grams) at 250 knts (128.6 m/s) = 15,000K joules.
A 15 lb Canada Goose (6800 grams) at 250 knts (128.6 m/s) = 56,229K joules.

Summary:
The four lb bird delivers 47 times the impact energy of the bullet!
The Canada Goose delivers 176 times the impact energy of the bullet!

[jerboy]

Summary:
The four lb bird delivers 47 times the impact energy of the bullet!
The Canada Goose delivers 176 times the impact energy of the bullet!

True, but the energy from the bullet is much more concentrated. The contact area for a bullet on the screen would be what? A few square mm?

However as the bird goes splat, its energy is spread out over a much larger area. You need to work out joules/mm^2 (or equivalent).

Put it like this - If I had the choice of standing behind a windshield facing either a bullet or a bird... I'd choose the bird. But as we've heard here, the windshields are pretty strong, so reckon I'd be safe anyway!!