GM1 SERA.6005(b) Requirements for communications and SSR transponder

CAA ORS9 Decision No.10

TRANSPONDER MANDATORY ZONE

A TMZ is established for overriding safety reasons where the airspace classification would not normally require the carriage of a transponder but where a change to a more restrictive classification of controlled airspace is not warranted.  A TMZ creates a ‘recognised air traffic environment’ within which ATS, where provided, are more able to provide enhanced levels of safety to aircraft and can enable the operation of airborne and ground-based safety nets.  The existence of a TMZ does not confer or suggest any particular airspace classification.