4.82 Communications and Equipment

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

AIP ENR 1.6

To indicate an emergency condition, the pilot should set the transponder to:

• 7700

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

AIP ENR 1.6

To indicate a loss of communications, the pilot should set the transponder to:

• 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

AIP ENR 1.6

To indicate that the aircraft is being subjected to unlawful interference, the pilot should set the transponder to:

• 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 

When ATC observes an aircraft transmitting code 7500, the controller will attempt to confirm that the code was selected intentionally by asking:

• “[Call sign], confirm squawking seven five zero zero.”

If the pilot:

• confirms the code; or
• does not reply,

ATC will assume that the aircraft is being subjected to unlawful interference.

4.82.10 Describe the use of the speechless technique using unmodulated transmissions. AIP ENR