What does the term deadhead (DH) refer to in aviation?

The term "deadhead" (DH) in aviation specifically refers to the transportation of crew members—such as pilots or flight attendants—who are traveling at the direction of the airline to or from a duty assignment. This can occur when they need to reach a specific location to operate a flight, or when they are returning home after completing their flight duties.

When a crew member is deadheading, they are not actively working a flight; instead, their transportation is essential for ensuring that the airline has the necessary personnel available for upcoming flights. This helps maintain operational efficiency and ensures that all scheduled flights are adequately staffed.

The other choices, while related to airline operations, do not capture the meaning of deadheading. For instance, attending training or conducting passenger deplaning processes involves active duty, rather than being a transport for assignment purposes. Similarly, an emergency evacuation drill pertains to safety procedures and does not relate to the movement of crew members for duty-related travel.