Thomas Cook cracked Windshield A320 - Full emergency at BRS 9/2/09
Join Date: Jan 2006
Location: Georgia, USA
Posts: 454
Likes: 0
Received 0 Likes
on
0 Posts
Here's a section from a Lear windscreen. (The things you find lying around ... 
)
) 
Join Date: Mar 2000
Location: Arizona USA
Posts: 8,571
Likes: 0
Received 0 Likes
on
0 Posts
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.
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.
Join Date: Dec 2007
Location: Italy Mainly
Posts: 36
Likes: 0
Received 0 Likes
on
0 Posts
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.
If I knew how to attach a pic of it to this, I would ! Help? ...
Level 400
It seems the other layers are mighty strong, even with the outer one broken.
If I knew how to attach a pic of it to this, I would ! Help? ...
Level 400
Join Date: Jan 2006
Location: London
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
Chickens...
Originally Posted by glhcarl
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.
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.
Join Date: Feb 2008
Location: Seattle
Posts: 167
Likes: 0
Received 0 Likes
on
0 Posts
What's In Your Windscreen?
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!
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!
Join Date: Nov 2004
Location: North East
Age: 37
Posts: 204
Likes: 0
Received 0 Likes
on
0 Posts
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!
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!
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!!
