How does a failure of the aircraft hydraulic system affect the brake system?

The correct choice indicates that a failure of the aircraft hydraulic system has no effect on the brakes. This suggests that the aircraft's braking system is designed in such a way that it either does not rely on the hydraulic system for functionality or has an alternate method for operating effectively even if the hydraulic system fails.

In many aircraft designs, the braking systems can function independently of hydraulic pressure, utilizing mechanical systems or alternative pressures to engage the brakes. This ensures that pilots can maintain control of the aircraft and safely land, even in the event of a hydraulic failure.

Understanding that hydraulic systems generally do play a critical role in numerous aircraft systems, it is essential to know that some brakes might still be operational through backup systems or different mechanisms, which accounts for the assertion that the failure of the hydraulic system would not affect brake functionality.

This context highlights the importance of engineers designing systems with redundancies to enhance safety even during partial system failures.