How is an 'accident' defined in aviation terms?

In aviation terms, an 'accident' is defined specifically as an event that results in death or serious injury occurring during flight operations. This definition captures the severity and context in which an accident is assessed in aviation safety regulations. It encompasses not just the physical impacts on aircraft but also considers the broader implications of human safety and potential loss of life during operations, which is the primary concern of regulators and safety investigators.

The significance of this definition is foundational to how aviation incidents are reported and analyzed; incidents that do not meet this criterion may fall into different classifications, such as incidents or occurrences, which do not carry the same level of scrutiny. Thus, option D captures the essence of aviation safety and regulatory focus, distinguishing meaningful accidents from other types of events that may occur in the context of flight operations.