What happens to the windshield when it is heated?

When the windshield is heated, it becomes pliable due to the thermal expansion of the materials used in its construction. This pliability is critical, especially in the context of aircraft, as it allows the windshield to better absorb changes in temperature and pressure. A pliable windshield can better withstand the stresses experienced during flight, such as rapid temperature changes when entering and exiting different altitudes and environments.

In contrast, if the windshield were to become opaque, this would impede visibility, which is not desirable for flight safety. Remaining brittle would make the windshield more susceptible to cracking or breaking under stress. Lastly, while heating might have an impact on performance aspects related to aerodynamics, the direct effect of heat on the windshield itself is primarily its increased pliability, enabling it to function safely and effectively under varying atmospheric conditions.