Definition
A lighter-than-air aircraft that is both powered (by an engine and propeller) and steerable, allowing it to be navigated under its own control rather than drifting with the wind. Dirigibles use a large gas-filled envelope (typically helium or, historically, hydrogen) to provide lift and include rigid airships, semi-rigid airships, and non-rigid airships (blimps).
Plain English
A powered, steerable airship — like a blimp or zeppelin — that floats because it is filled with a gas lighter than air, and can be flown in a chosen direction using engines and control surfaces.
Context Anchor
Seen in aircraft classification, airframe, and maintenance discussions involving airships and other lighter-than-air aircraft.
Derivation
From the French 'dirigible,' meaning 'steerable' or 'directable,' from Latin 'dirigere' (to direct or guide). The name highlights what sets a dirigible apart from a free balloon: a balloon drifts with the wind, but a dirigible can be directed.
Why Pilots Care
It distinguishes a powered, controllable airship from a free balloon. The category affects certification, handling, and the type of operations the aircraft is approved for.
Intuition Check
Do not read dirigible as just “a balloon.” A balloon may drift with the wind; a dirigible is built to be steered and powered.
Example Sentence 1
The hangar was originally built in the 1930s to house a large rigid dirigible.
Example Sentence 2
Early dirigibles used internal frames and engines to maintain controlled flight paths over long distances.