Hav eyou ever wondered why plane windows are curved as opposed to square-shaped? There’s a simple reason that has to do with air density that is lower up high, creating less drag for airs. This means that the cabin must be pressurized. Over thousands of cycles, cracks can form from high-stress locations and square windows provide a significant barrier to the smooth flow of stress as the stress peaks at the sharp corner of the window.

This is why all airliners feature oval windows to avoid this stress concentration. Comprehensive fatigue testing is required before a plane can be approved by the FAA. We often learn the most from our failures, this is particularly true for advancements in the field of engineering. These are now two basic concepts that every materials engineer is taught, these events allowed us to further our understanding of materials and prevent further failures.