Bob Moore wrote:

Juergen Nieveler wrote

Zeppelins are aircraft.

No. They're airships. "Aircraft" normally refers to heavier-than-air-
vehicles.

From FAR Part 1

Aircraft means a device that is used or intended to be used for flight in
the air.

Yup, an airship is an aircraft as is an airplane, but an airship an
airplane. Or, to quote the FAR under definitions, "'Airship' means an
engine-driven lighter-than-air aircraft that can be steered." "'Airplane'
means an engine-driven fixed-wing aircraft heavier than air, that is
supported in flight by dynamic reaction of the air against the wings."

Guy