7500 – Unlawful Interference
7600 – Radio failure
7700 – Emergency condition
7000 – VFR (visual flight rules) conspicuity code
2000 – When entering UK airspace from adjacent region where the operation of transponders has not been required.
7500 – Unlawful Interference
7600 – Radio failure
7700 – Emergency condition
7000 – VFR (visual flight rules) conspicuity code
2000 – When entering UK airspace from adjacent region where the operation of transponders has not been required.