Why some airliners have the "eyebrow" cockpit windows?

Question

Mostly the old birds and 737s have them, Why the new airliners don't have such windows?
http://www.airliners.net/open.file/1184118/L/

Answer 1

The need for the skyward looking windows has gone away with the integration of much more advanced traffic tracking systems, it is rarely necessary in an airliner to look for traffic other than at the small TCAS screen in the center console... Also, doing away with windows helps the cabin stay pressurized more easily... the fewer the windows, the fewer the small leaks...

Answer 2

The eyebrow windows were introduced on the 707 (at least for Boeing). In a turn, with the airplane banked, it was hard to see traffic if you were turning toward the opposite side of the airplane from where you were sitting (i.e., in the left seat and turning right, or in the right seat turning left). The eyebrow windows allowed the pilot to see where the airplane was going.

The eyebrow windows for the 707/727/737 are not all that expensive, at least when compared to the #1 window (the windshield). The #4 and #5 eyebrow windows typically run anywhere from about $1900 each to $2600 each; the market fluctuates quite a bit. Coincidently, they're all interchangeable between the 707, 727, and 737; Boeing never re-invents the wheel.

Now in the modern days, we have things like TCAS to help us keep airplanes from sharing the same airspace. There is at least one STC (an approved modification package) that allows you to delete the eyebrow windows on the 727 and 737 and replace them with metal plugs that will last practically forever (unlike the windows, which are a pretty high failure-rate item).

Answer 3

Eyebrow Window

Answer 4

ALOPILOT is correct in his answer.
The only thing I can add is from the manufacturing/engineering stand point.
First off, the window cost approximately $10,000. Eliminating it is much cheaper.
Also, any time you cut a hole in the exterior skin, (like to add a window) you weaken that area. To replace the strength, the area around it has to be beefed up with a torque box type structure, adding weight, reducing fuel economy (not much for 2-4 windows, but multiply by every other weight saving method, it adds up).

Answer 5

Eyebrows aren't sexy anymore. Many people shave them. Planes did the same thing.

As time goes on, I expect some planes to change their minds and start penciling eyebrows in with eyeliner.

Answer 6

All your viewing is on instruments