How is the term "blocked aircraft" best described?

The term "blocked aircraft" is best described as an aircraft that is being loaded or unloaded. This terminology is commonly used in aviation to indicate that an aircraft is temporarily out of service because it is engaged in the process of preparing for departure or having passengers and cargo disembarked. During this time, the aircraft is considered "blocked" from being utilized for another flight until loading or unloading is completed and it is ready to take off.

In operational contexts, aircraft may be "blocked" at gates or ramp areas as they undergo various pre-flight or post-flight procedures, including fueling, crew boarding, and maintenance checks. Understanding this definition is crucial for personnel involved in flight operations, scheduling, and ground handling, as it affects flight timelines and resource allocation.