What defines the fourth level of integrity in the aircraft's power system?

The fourth level of integrity in an aircraft's power system is defined by the loss of one generator. In aviation, particularly in the context of multi-engine aircraft with redundancy in their power systems, the power setup is designed to maintain functionality despite certain failures.

When discussing levels of integrity, each level corresponds to different failure scenarios and their impact on the aircraft's operations. The loss of one generator signifies a critical point where the system is still functional but is operating at reduced capacity. This means that while one generator goes offline, the other generator continues to support essential systems, maintaining a level of operational integrity.

As operations typically rely on multi-redundant systems to ensure safety, understanding the implications of a single generator loss is crucial. It emphasizes the importance of generator redundancy in flight safety and operational reliability, illustrating that while there is degradation in power capacity, the aircraft can continue to function safely and effectively until corrective measures are taken.