Lesson 3 of 4 — Module 5: Airspace, services & transponders

Mandatory zones — RMZ & TMZ

Radio and Transponder Mandatory Zones — entry requirements, radio and transponder failures, and the calls and permissions needed.

Listen to this lesson (~1 min)

Mandatory zones — RMZ & TMZ — narrated, hands-free

RMZ & TMZ (mandatory zones)

RMZ — Radio Mandatory Zone

You must ESTABLISH two-way radio contact with the notified unit BEFORE you enter. Two-way is achieved only once you've passed your callsign, aircraft type, position, level, flight rules and intentions AND received an acknowledgement. If you can't make contact, stay outside. Marked “RMZ” on the chart.

TMZ — Transponder Mandatory Zone

You must have a serviceable transponder operating with the correct mode (Mode S / Mode C — “squawk Charlie”). If you can't comply (no transponder or a failure), get permission from the controlling unit first, otherwise remain outside. Marked “TMZ” on the chart.

Practise & test

Practise: Exercise I: Mandatory zones (RMZ & TMZ)5 graded calls · spoken or typed, marked against CAP 413

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Next lesson: Transponder squawk codes →

Study aid only — always defer to CAP 413 and current official publications, and to your instructor and examiner.