Boeing 737 windscreen cracks

[flyboy2]

Jet's windscreen cracks 2005-12-03

16:36:56http://www.news24.com/Images/Photos/20051203143941boeing737.jpg
An Australian jet's windscreen has cracked mid-flight, causing a major scare when the cabin rapidly decompressed. Sydney - An Australian jet's windscreen has cracked mid-flight, causing a major scare when the cabin rapidly decompressed.

A Queensland state ambulance service spokesperson said nine people were treated in hospital for nosebleeds, nausea and earaches after the Virgin Blue Boeing 737 made an emergency landing at Brisbane airport on Friday morning.

He said the pilot was forced to rapidly descend from 10 400 to 3 000 metres when an outer windscreen cracked during a flight from Townsville to Brisbane.

The Australian transport safety bureau said it was investigating the incident.

News24/AFP

[captplaystation]

Unusual if only an outer windscreen could cause a rapid depress, I was led to believe inner would take load & descent was only precautionary;maybe I have been (mis)led ?

[Accident Prawn]

I have had a cracked windscreen on a 737 last year.
Happened at EDI after V1 exactly. Multiple fractures, outer pane.
Continued take off, re landed from 3000' at night.
Expected a facefull of glass at any time, but not a thing.
Uneventful landing, changed aircaft, back flying 1.5 hours later.

[Panman]

Let's see, they say windscreen. Which makes me assume one of the jobbies at the pointed end at the front. If such then what inner/outer pane are you talking about considering that it's an assembly that consists of many layers of vinyl, gold leaf, electrical contacts etc.

If they meant one of the windows that the cattle look out of then yes, your use of inner and outer panes is correct.

[stator vane]

the book calls it a two pane glass assembly. that's good enough for me.

i was in the right seat about 1993 when at TOD on a flight from vegas to seattle, just when the thrust levers came back on the descent, and a loud crash sound and we noticed the captains windshield all cracked and opaque but still holding together somehow.

after tightening up our seat belts and doing the checklist, i flew the rest of the flight since i could see out my two pane winshield with no other problem.

if you hold the white laminated checklist edge up against the windshield and vary the angle, you will see the assembly and the vinyl sheet in between. or examination the reflections of the instruments on the windows at night time and count the reflections. each surface of glass makes a separate layer of reflection.

that noise will stay in my memory forever.

[DownIn3Green]

On the 727 and 737 the inner pane is the limiting factor...obvivously it may be prudent to descend to a lower altitude but to my recollection there is no restriction on continued flight with a broken/shattered outer pane...

[Sunfish]

From what I recall, after tracing zillions of changes of part numbers, the acrylic layers are the structural ones and the glass is there on the outside for abrasion resistance. The inside glass has the heater layer because the Acrylic strength is only within a certain temperature band.

Ask PPG, they make most of them .

[small4]

The B737 Non Normal Checklist for Window Damage (Arcing, substantial delamination, shattering or cracking of any flight deck window) shows a Max Diff Pressure for a single pane failure of 5 psi (approx 26,000ft) and 2 psi (approx 15,000ft) for a dual pane failure. No recall items are required and no mention is made of the type of descent required to satisfy the above differential pressure requirements.

That being said, it will certainly grab your attention.

[James T. Kirk]

I had this a couple of nights ago climbing through FL260. Just closed the taps and headed back home doing the check list on the way. The depressurisation was so gentle I couldn't even feel it. That was at 260 and using the DCPCS though.

That cracking sound does get your attention.

[beauport potato man]

had a similar incident in the ol' 146 last month.

FL180 at 300 kts (thats fast for a quadrapuff) over nedul when my windscreen started arcing, then the outer pane shattered.

A quick pan issued and a precautionary divert to SOU, with the captain taking PF duties.

As stator vane said, it's a sound that'll live in your memory forever.

BPM

[IFixPlanes]

AMM says:
The construction of window No. 1 consists of a glass pane laminated to each side of a polyvinyl butyral (vinyl) interlayer .
The inner glass pane is the thicker of the two and is the primary load carrying member. The vinyl interlayer acts as the "fail-safe" load carrying member. The outer pane has no structural significance, but provides rigidity and a hard, scratch resistant surface.
Detailed view:
http://img180.imageshack.us/img180/5230/b737window18yv.th.jpg (http://img180.imageshack.us/my.php?image=b737window18yv.jpg)

Overview:
http://img180.imageshack.us/img180/1175/b737windows5sw.th.jpg (http://img180.imageshack.us/my.php?image=b737windows5sw.jpg)

[Wing Commander Fowler]

Captain Kirk - those ole VEX classics still creep that high do they??? Hehe! :}

[Flight Detent]

Hi all,

As per DownIn3Greens, my understanding is that there is no restriction on continuing the flight at whatever altitude!!

The trick is to positively determine which layer has actually cracked!

Cheers, FD

[FCS Explorer]

to get an idea which layer is broken hold something to the window, like a pen or whatever. from the point where it touches you can get an idea how far the cracked layer is away.
i've been in an incident where we would've been able to continue flying for days. breakfast at dawn, bright glowing point appears in the sliding window and start eating its way thru the window. flipped OFF the window heat instantly, glow ceases. while we're still wondering -BANG- window covered in cracks. not funny. figured out it was the outer pane. but since the manuals don't contain advise on melting, glowin windows we went straight into emg desc.
since the side sliding window is inches from my head i felt quite uneasy. started to relax around 10.000ft as we depressurized the can.
if u tell me a window in the cabin blows, it's still something i wouldn't like. but better in the cabin than next to my face.

and one more thing: MEL window heat:
u can fly some days without. it's fine in the books. but: a 737 usually does some 2-10 (?) cycles a day. temperature change grd-FL summer 90°K, winter maybe still 60°K.
talking stressed materials.

[Few Cloudy]

If this really happened it would have been due to subsequent actions rather than the pane cracking.