AFZ and AZF both refer to the highest-level German radio communication certificate required for certain types of flying within German airspace. These acronyms are used interchangeably:
AFZ – Allgemeines Funksprechzeugnis
AZF – Allgemeines Flugfunkzeugnis
The abbreviation may differ depending on the document source (e.g. EASA vs. LBA), but they denote the same qualification.
The AFZ/AZF certificate does not expire. However, language proficiency, especially in English, must be revalidated according to ICAO language level requirements (usually every 4 to 6 years, depending on the level achieved).
In Practice
Holding an AFZ means a pilot is fully certified for all radiotelephony communication required in German and international airspace, including complex IFR scenarios and multilingual operations.