2. Aircraft Safety Features
Windows, Icons, and Sounds Airplane windows are designed to withstand high-altitude pressure differentials, and the small hole at the bottom helps balance the air pressure between the panes. Cabin interiors often feature small red or black triangles, indicating the best viewing spots for cabin crew to inspect the wings. Meanwhile, the various sounds you hear during a flight serve as communication tools for the crew, indicating turbulence, altitude changes, or emergencies.
