Definition
The mechanical stresses placed on an aircraft's structure -- particularly the fuselage, windows, and windshields -- by the pressure difference between the pressurized cabin interior and the lower-pressure outside air at altitude.
Plain English
The forces pushing outward on the aircraft skin and windows because the air inside the cabin is at a higher pressure than the air outside.
Context Anchor
Seen in discussions of pressurized aircraft windshields, especially when considering windshield strength, heating, icing, cracks, or damage.
Derivation
Pressurization comes from Latin pressura, meaning 'a pressing.' A 'load' in engineering is any force a structure has to carry. So a pressurization load is simply the force the structure must carry because of the pressure difference between inside and outside.
Why Pilots Care
Icing can create cracks or weak points that cause the windshield to fail under these forces, leading to rapid depressurization.
Analogy
It is like pressing your hand against one side of a window. The window may look still, but it is carrying a force across its surface.
Grounding Statement
At cruise altitude, the cabin is held at a comfortable pressure while outside air is much thinner -- the difference pushes outward on every square inch of the aircraft's skin and windows.
Intuition Check
Do not read “loads” as baggage or cargo here. In this context, loads means forces or stresses acting on the windshield.
Example Sentence 1
The windshield is built in layers so it can carry pressurization loads even if one layer is damaged.
Example Sentence 2
Even small ice damage may reduce the windshield's ability to handle pressurization loads at cruising altitude.