Read more for transponder codes, used in Bulgarian Virtual Airspace


Transponder Codes in Bulgarian Virtual Airspace


LBSF (SOFIA) 4701 4777
LBWN (VARNA) 3401 3437
LBBG (BURGAS) 3441 3477
LBPD (PLOVDIV) 3201 3247
LBGO (GORNA) 3251 3277

Special Transponder codes:

Squawk codes also enable the controller to easily locate a aircraft in an urgency or an emergency situation before being contacted by the pilot.

Transponder codes are usually assigned by the controllers except for those 4 dedicated to specific situations :

  • 7700 - Emergency, this will be an indication on the controller's screen that your aircraft has experienced an emergency.
  • 7600 - Radio Failure, this code is not used very often on IVAO because we have both Text and Voice communications. If you would like to simulate    lost comms procedures, make sure to check with your controller first.
  • 7500 - Hijack, this code is a part of the tutorial for informational purposes only. Although terrorism and war exist in the real world we in IVAO do not allow the simulation of any kind of aggression or armed violence on our network. This rule can be found here
  • 2000 - default transponder code for an aircraft which has not received any instructions from air traffic control units to operate the transponder.

    Note: In some countries, a non-discrete squawk such as 1200, 7000, .... may be used by VFR's in uncontrolled airspace. Check the country regulations of the Division for more information.

  • 1000 - non discrete code used in Mode S airspace where the flightplan is not correlated using a squawk code but using the aircraft identification.