4.82 Communications and Equipment

4.82.2 State the transponder code a pilot should set to indicate an emergency condition. AIP ENR

7700

4.82.4 State the transponder code a pilot should set to indicate a loss of communications. AIP ENR

7600

4.82.6 State the transponder code a pilot should set to indicate that the aircraft is being subjected to unlawful interference. AIP ENR

7500

4.82.8 Describe the means by which ATC will verify the transmission of an emergency SSR transponder code. AIP ENR

ENR 1.13 UNLAWFUL INTERFERENCE 

1 ACTIONS AND PROCEDURES 

1.1 General 

1.1.1 The pilot of an aircraft subject to unlawful interference or the threat of unlawful interference must endeavour to advise ATS of the fact, together with details of any subsequent deviation from the current flight plan, and any other significant factors affecting the operation. This will enable ATS to give priority to the aircraft and alert organisations likely to be involved.

1.2 Procedures 

1.2.1 The following procedures should be followed:

• (a) switch transponder to code 7500 MODE A;
• (b) advise ATS of details in plain language if possible;
• (c) if use of radio is restricted, insert the phrase “CHANNEL SEVEN FIVE ZERO ZERO” into any RTF transmission after the aircraft’s callsign, if it is safe and practicable to do so.