The B737 was certified to FAR 25 standards for bird strikes - a 4 lb bird at Vc (design cruise speed). That being said, high speed flight below 10,000 feet is a high risk activity with respect to bird strikes. The certification standard assumes only a single bird impact and the standard does not require that there is "no damage". While the probability of bird strikes does reduce with altitude the problem is that as altitude increases the bird species struck are large - waterfowl or raptors - many of which exceed four pounds weight. Further to this the certfied standard produces an impact force; that force increases as the SQUARE of the speed increase and as a direct function of the bird weight. It is also important to remember that when climbing at a constant IAS the TAS increases with altitude. The last piece of the equation is that during the acceleration phase rate of climb is reduced - right in the middle of the bird rich altitudes. So add up the risks; bigger birds, more exposure and probability during acceleration and increased severity. I did a detailed risk analysis on this for Transport Canada and the results are very sobering.
As for what Vc for the B737 is, I don't have that information, but in my mind it doesn't matter. For more information I suggest you read sections of the Transport Canada book Sharing the Skies, available online at:
http://www.tc.gc.ca/CivilAviation/Ae...13549/menu.htm
The last point is that not only do you need to consider the windshield you need to consider the aircraft structure....
I have lots of pictures, but I need to figure out how to post them.
So those who are not worried about hitting a bird at 335 knots need to rethink their position.
Remember if you operate in North America or Europe that currently there are millions of bird migrating north over the next few weeks.....