Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Furnishings and Equipment (hierarchy name)
4. Transportation Vehicles (hierarchy name)
5. vehicles (transportation)
6. air and space transportation vehicles
7. aircraft
8. [aircraft by form]
9. lighter than air aircraft
10. balloons (aircraft)

Anotations

Scope note:

Small free balloons carrying self-registering instruments aloft to record and transmit measurements for atmospheric research; for balloons carrying aloft instruments for recording weather-related data, use "meteorological balloons."