What is the term for a flight that has to change its destination while in the air?

The term for a flight that has to change its destination while in the air is "Diversion." This situation often arises due to various circumstances such as inclement weather, medical emergencies, or issues at the original destination airport that prevent a safe landing. When a pilot decides to divert, they will choose an alternate airport to land, and this can happen at any point during the flight after departure.

In the context of aviation, a diversion is an essential operational decision that prioritizes safety and compliance with regulations. It involves coordination with air traffic control and can sometimes require adjustments to the flight route and fuel management.

Other terms like domicile, ferry/repo flight, and holding have specific meanings that do not apply in this context. Domicile refers to the base location of an airline or crew, ferry/repo flights typically involve moving aircraft without passengers or cargo, and holding describes a situation where an aircraft must remain in a specific area of the airspace, usually waiting for clearance to land. These terms do not capture the essence of a flight changing its intended destination while in transit, which is why "Diversion" is the correct answer.