ATPL Forum Practice Test

An under-inflated tire significantly affects how the tire makes contact with the runway surface. When a tire is under-inflated, it does not maintain its proper shape and can lead to uneven wear. Specifically, the outer edges or shoulders of the tire may come into more contact with the runway, resulting in increased wear in those areas. This uneven wear can compromise the tire's overall performance and safety over time.

In contrast, tire pressure that is within the recommended range ensures that the tire maintains optimal contact with the runway, promoting even wear and longer tire life. This is particularly important on a dry runway, where effective traction and braking performance are crucial. Thus, under-inflation can lead to premature tire replacement and potential safety hazards due to reduced traction and control.