Definition
A lighter-than-air balloon held in place by a tether or cable attached to the ground or to a fixed object, preventing free flight. The balloon rises by buoyancy from a lifting gas or heated air, but its position and altitude are limited by the length of the restraining line.
Plain English
A balloon that floats up into the air but stays connected to the ground by a rope or cable, so it cannot drift away.
Context Anchor
Seen in discussions of balloons, airspace hazards, and obstacles that may be marked or reported because a tethered balloon can extend upward into navigable airspace.
Derivation
From the Latin captivus meaning 'held' or 'taken prisoner.' The balloon is 'captive' because it is held by its tether and not free to fly.
Why Pilots Care
These balloons can create unexpected obstacles to flight and must be avoided for safety.
Analogy
It is like a kite on a string: the object is in the air, but it is still connected to the surface and cannot simply go where the wind wants to take it.
Intuition Check
Captive does not mean the balloon is carrying prisoners or passengers being held. Here it means the balloon itself is restrained by a line or cable.
Example Sentence 1
A NOTAM warned pilots of a captive balloon operating up to 500 feet AGL near the showground.
Example Sentence 2
During the weather briefing the instructor mentioned a captive balloon used for local advertising that could affect low-level traffic.