Window seat not a guarantee on all planes

Q: I recently flew from DCA to SLC and requested a window. When I got to my seat there was no window, only solid wall. What is the purpose of leaving out of certain slots where one would expect a window?

— Dean Flanders, Layton, Utah

A: When jets are certified, one consideration is the consequence of a catastrophic engine failure, where rotating engine components are not contained within the cowling. In the very rare event of uncontained parts puncturing through the cowling, it is possible that they could strike a window, causing damage and decompression. This area is strengthened, and the area where the window would normally be is solid.

Q: Why are cabin windows always placed in such a way that most people need to bend down to look straight out when seated, especially as humans have become taller over the years?

— Mark Mather, Eindhoven, Netherlands

A: The manufacturers place windows in locations where there is little stress. It might be possible to raise them or increase the size. Some of the newer airplanes, such as the Boeing 787, have larger windows.

Q: Why are the windows on passenger aircraft so small and rounded?

— Submitted via email

A: The shape of the window ensures that cracking does not occur due to pressurization cycles. This was the cause of accidents on the first commercial jet, the De Havilland Comet.

The size is due to design considerations of a failing window causing a pressurization leak. The smaller size helps the pressurization system keep the cabin partially pressurized in the event of failure.