Transponder Mandatory Zone (TMZ) means airspace of defined dimensions wherein the carriage and operation of transponder equipment is mandatory.
All flights operating in airspace designated by the competent authority as a TMZ shall carry and operate Secondary Surveillance Radar (SSR) transponders capable of operating on Modes A and C or on Mode S, unless in compliance with alternative provisions prescribed for that particular airspace by the Air Navigation Service Provider (ANSP)
A pilot wishing to operate in a TMZ without serviceable transponder equipment may be granted access subject to specific arrangements agreed with the TMZ Controlling Authority.