Definition
An unmanned balloon, not tethered to the ground, that drifts freely with the wind and carries a payload of two or more packages with a combined weight specified in the regulations. Operations of these balloons are governed by 14 CFR Part 101, which sets rules on launch conditions, equipment, lighting, and reporting to ATC.
Plain English
A balloon with no pilot on board and no rope holding it down, that floats wherever the wind takes it while carrying instruments or other cargo. It is regulated because it shares the sky with aircraft.
Context Anchor
Seen in FAA rules and flight planning discussions about balloons that may be released into navigable airspace.
Derivation
‘Unmanned’ means no person on board. ‘Free’ here means untethered — not attached to the ground or to another object — so the balloon drifts with the wind rather than being held in place.
Why Pilots Care
These balloons can ascend into controlled airspace and create unexpected collision hazards for powered aircraft.
Analogy
Think of a released party balloon drifting away, but on an aviation scale: it may be larger, may carry equipment, and may reach altitudes where aircraft operate.
Intuition Check
“Free” does not mean free of charge here; it means not tied to the ground. “Unmanned” means no person is onboard, not that no one is responsible for launching or tracking it.
Example Sentence 1
Before launching the unmanned free balloon, the operator notified the nearest ATC facility as required by Part 101.
Example Sentence 2
Unmanned free balloons released for weather research may drift across several states and affect multiple airports.