ENR 1.13 UNLAWFUL INTERFERENCE

1 
An aircraft which is being subjected to unlawful interference shall endeavour to notify the appropriate ATS unit of this fact, any significant circumstances associated therewith and any deviation from the current flight plan necessitated by the circumstances, in order to enable the ATS unit to give priority to the aircraft and to minimize conflict with other aircraft.
2 
An aircraft equipped with an appropriate data link capability and/or an SSR transponder might operate the equipment as follows:
  1. On Mode A, Code 7700;
  2. On Mode A, Code 7500, to indicate specifically that it is being subjected to unlawful interference;
  3. Activate the appropriate emergency and/or urgency capability of ADS;
  4. Transmit the appropriate emergency message via CPDLC.