ENR 1.13  UNLAWFUL INTERFERENCE

1.   General

The following procedures are intended for use by aircraft when unlawful interference occurs and the pilot is unable to notify an ATS unit of this fact.

2.   Procedures

2.1.  Unless considerations aboard the aircraft dictate otherwise, the pilot-in-command should attempt to continue flying on the assigned track and the last cleared and acknowledged cruising level, at least until notification to an ATS unit is possible.
2.2.  When an aircraft subjected to an act of unlawful interference must depart from its assigned track or its cruising level without being able to report this fact to the ATS unit concerned, the pilot-in-command should, whenever possible:
  1. endeavour to set the transponder to Mode A/C, Code 7500, to give indication of the situation, unless circumstances warrant the use of Code 7700.
  2. When a pilot has selected Mode A/C, Code 7500 and the request of ATC to confirm this code setting will not be replied, the absence of reply from the pilot will be taken by ATC as an indication, that the use of code 7500 is not due to an inadvertent false code selection.