List of transponder codes

The following list shows specific aeronautical transponder codes, and ranges of codes, that have been used for specific purposes in various countries. Traditionally, each country has allocated transponder codes by their own scheme with little commonality across borders. The list is retained for historic interest.

Pilots are normally required to apply the code, allocated by air traffic control, to that specific flight. Occasionally, countries may specify generic codes to be used in the absence of an allocated code. Such generic codes are specified in that country's Aeronautical Information Manual or Aeronautical Information Publication. There also are standard transponder codes for defined situations defined by the International Civil Aviation Organization (marked below as ICAO).

Transponder codes shown in this list in the color RED are for emergency use only such as an aircraft hijacking, radio communication failure or another type of emergency.

Code Countries Allocated use
0000 Europe Non-discrete mode A code; shall not be used.[1]
UK Mode C or other SSR failure[2]
US Should never be assigned.[3]
Military intercept code.[4]
Internal ARTCC subsets assigned by Enroute Safety and Operations Support. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
0021 Germany (VFR squawk code for airspace 5,000 feet (1,500 m) and below prior to 15 March 2007 when replaced by the international 7000 code for VFR traffic.)[5]
0022 Germany (VFR squawk code for airspace above 5,000 feet (1,500 m) – prior to 15 March 2007 when replaced by the international 7000 code for VFR traffic.)[5]
0025 Germany Parachute dropping in progress.[citation needed]
0033 UK Parachute dropping in progress.[2]
0041–0057 Belgium Assigned for VFR traffic under Flight Information Services (BXL FIC).[citation needed]
0100 Australia Flights operating at aerodromes (in lieu of codes 1200, 2000 or 3000 when assigned by ATC or noted in the Enroute Supplement).[6]
0100–0400 US Allocated to Service Area Operations for assignment for use by Terminal/CERAP/industry/unique purpose/experimental activities.[3]
0100–0700 US Non-discrete code assignments in accordance with FAA Order JO 7110.65, 5-2.
US Also for use in oceanic airspace unless another code is assigned by ATC.[3]
0500, 0600, 0700 US External ARTCC subsets. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
1000 Canada Instrument Flight Rules (IFR) flight below 18,000 ft ASL when no other code has been assigned.[7]
ICAO Non-discrete mode A code reserved use in mode S radar/ADS-B environment where the aircraft identification will be used to correlate the flight plan instead of the mode A code.[1]
US Used exclusively by ADS-B aircraft to inhibit mode 3A transmission.[3]
US Non-discrete code assignments in accordance with FAA Order JO 7110.65, 5-2. Also for use in oceanic airspace unless another code is assigned by ATC (US).[3]
US External ARTCC subset. (Block of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
1100 US Non-discrete code assignments in accordance with FAA Order JO 7110.65, 5-2. Also for use in oceanic airspace unless another code is assigned by ATC.[3]
US External ARTCC subset. (Block of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
1200 Australia Civil VFR flights in class E or G airspace.[6]
Canada, US Visual flight rules (VFR) flight standard squawk code used in North American airspace when no other has been assigned or is applicable.[7][3]
1201 US Assigned via FAR 93.95 for use by VFR aircraft in the immediate vicinity of LAX.[3]
US (Visual flight rules (VFR) glider operations for gliders not in contact with ATC, through February 2012.[8])
1202 US Visual flight rules (VFR) glider operations for gliders not in contact with ATC; effective February 2012.[3][9]
Canada Visual flight rules (VFR) glider operations for gliders not in contact with ATC; effective February 2017.[7][10]
1203–1272 US Discrete 1200 series codes unless otherwise allocated (for example, 1255), designated for DVFR aircraft and only assigned by a flight service station.[3]
1255 US Aircraft not in contact with an ATC facility while enroute to/from or within the designated fire fighting area(s).[3][11]
1273–1275 US Calibration Performance Monitoring Equipment (CPME) "Parrot" transponders.[3]
1276 US Air Defense Identification Zone (ADIZ) penetration when unable to establish communication with ATC or aeronautical facility.[3]
1277 US VFR aircraft which fly authorized SAR missions for the USAF or USCG while enroute to/from or within the designated search area.[3][11]
1300 US Non-discrete code assignments in accordance with FAA Order JO 7110.65, 5-2. Also for use in oceanic airspace, unless another code is assigned by ATC.[3]
US External ARTCC subset. (Block of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
1400 Canada VFR flight above 12,500' ASL when no other code has been assigned.[7]
Japan VFR flight above 10,000' MSL when no other code has been assigned.[citation needed]
US External ARTCC subset. (Block of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
1500 US Non-discrete code assignments in accordance with FAA Order JO 7110.65, 5-2. Also for use in oceanic airspace unless another code is assigned by ATC.[3]
US External ARTCC subset. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
1600, 1700 US External ARTCC subsets. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
2000 Australia Civil IFR flights in class G airspace.[6]
Canada Uncontrolled IFR at or above 18,000 ft MSL.[7]
ICAO countries Code squawked when entering a secondary surveillance radar (SSR) area from a non-SSR area used as uncontrolled IFR flight squawk code.[1]
EASA countries Code that pilot shall set in the absence of ATS instructions related to code setting, unless when not receiving air traffic services.[12]
US Non-discrete code assignments in accordance with FAA Order JO 7110.65, 5-2. Also for use in oceanic airspace unless another code is assigned by ATC.[3]
US External ARTCC subset. (Block of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
2100 Australia Ground testing by aircraft maintenance staff.[6]
US Non-discrete code assignments in accordance with FAA Order JO 7110.65, 5-2.
US Also for use in oceanic airspace unless another code is assigned by ATC.[3]
US External ARTCC subset. (Block of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
2200, 2300, 2400 US Non-discrete code assignments in accordance with FAA Order JO 7110.65, 5-2.
US Also for use in oceanic airspace unless another code is assigned by ATC.[3]
US External ARTCC subsets. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
2500, 2600, 2700 US External ARTCC subsets. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
3000 Australia Civil flights in classes A, C and D airspace, or IFR flights in class E airspace.[6]
US External ARTCC subset. (Block of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
3100, 3200, 3300,
3400, 3500, 3600,
3700 		US External ARTCC subsets. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
4000 Australia Civil flights not involved in special operations or SAR, operating in class G airspace in excess of 15NM offshore.[6]
US Aircraft on a VFR Military Training Route or requiring frequent or rapid changes in altitude.[13]
US Non-discrete code assignments in accordance with FAA Order JO 7110.65, 5-2.
US Also for use in oceanic airspace unless another code is assigned by ATC.[3]
US External ARTCC subsets. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
4100 US External ARTCC subsets. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
4200, 4300 US Internal ARTCC subsets assigned by Enroute Safety and Operations Support. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
4400–4477 US Reserved for use by SR-71, YF-12, U-2, B-57, pressure suit flights, and aircraft operations above FL600.[3][13]
4401–4433 US Reserved in accordance with FAA Order JO 7110.67 (Federal Law Enforcement).[3]
4434–4437 US Weather reconnaissance, as appropriate.[3]
4440,4441 US Operations above FL600 for Lockheed/NASA from Moffett Field.[3]
4442–4446 US Operations above FL600 for Lockheed from Air Force Plant 42.[3]
4447–4452 US Operations above FL600 for SR-71/U-2 operations from Edwards AFB.[3]
4453 US High balloon operations: National Scientific Balloon Facility in Palestine, Texas; and other providers, some in international operations.[3]
4454–4465 US Air Force operations above FL600 as designated in FAA Order 7610.4.[3]
4466–4477 US Reserved in accordance with FAA Order JO 7110.67 (Federal Law Enforcement).[3]
4500, 4600, 4700 US Internal ARTCC subsets assigned by Enroute Safety and Operations Support. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
5000 Australia Aircraft flying on military operations.[6]
US, Canada Reserved for use by NORAD.[3]
5061, 5062, 5100,
5200 		US Reserved for special use by Potomac TRACON.[3]
5100, 5200, 5300,
5500 		US Internal ARTCC subsets assigned by Enroute Safety and Operations Support. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
5100–5300 US May be used by DOD aircraft beyond radar coverage but inside US controlled airspace with coordination as appropriate with applicable Area Operations Directorate.[3]
5400 US, Canada Reserved for use by NORAD.[3]
5600, 5700 US External ARTCC subsets. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
6000 Australia Military flights in class G airspace.[6]
US External ARTCC subset. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
6100 US, Canada Reserved for use by NORAD.[3]
6200, 6300 US External ARTCC subsets. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
6400 US, Canada Reserved for use by NORAD.[3]
6500, 6600, 6700 US External ARTCC subsets. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
7000 ICAO VFR standard squawk code when no other code has been assigned.[1]
EASA countries Code that pilot shall set when not receiving air traffic services, unless otherwise prescribed by the competent authority.[12]
US External ARTCC subset. (Block of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
Australia Unmanned aerial vehicle in all classes of airspace and when instructed to enable transponder.[6]
7001 France Used in some countries to identify VFR traffic.
UK Sudden military climb out from low-level operations.[2]
7004 UK Aerobatic and display code in some countries.[2]
7100, 7200, 7300 US External ARTCC subsets. (Blocks of discrete codes except that xx00 is used as a non-discrete code after all discrete codes are assigned.)[3]
Switzerland 7100 in Switzerland for SAR (REGA).[14]
7400 US, UK, Australia Unmanned aerial vehicle lost link.[15][16][17]
7500 ICAO Aircraft hijacking.[3][7]
7501–7577 US Reserved for use by Continental NORAD Region (CONR).[3]
7600 ICAO Radio failure (lost communications).[3][7]
7601–7607 US Reserved for special use by FAA.[3]
7610–7676 US External ARTCC subset (block of discrete codes).[3]
7615 Australia Civil flights engaged in littoral zone surveillance.[6]
7700 ICAO Emergency.[3][7]
7701–7707 US Reserved for special use by FAA.[3]
7710–7776 US External ARTCC subset (block of discrete codes).[3]
7776 Europe The Mode A code 7776 is assigned as a test code by the ORCAM Users Group, specifically for the testing of transponders.[18]
7777 US, Germany,
UK, Belgium,
Netherlands		 Non-discrete code used by fixed test transponders (RABMs) to check correctness of radar stations (BITE).
US DOD interceptor aircraft on active air-defense missions and operating without ATC clearance in accordance with FAA Order 7610.4.[3][19]

References

  1. ^ a b c d ICAO doc 4444 & ICAO Annex 10
  2. ^ a b c d "UK AIP ENR 1.6.2 – SSR Operating Procedures and UK SSR Code Assignment Plan" (PDF). UK Civil Aviation Authority. 2007-11-06. Archived from the original (PDF) on 2009-01-24.
  3. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk bl bm bn bo bp bq US Department of Transportation, Federal Aviation Administration. "JO 7110.66F, National Beacon Code Allocation Plan". US Government. Retrieved 2019-12-06.
  4. ^ "Radio Communications". Cleared for Takeoff: Your Handbook for Becoming a Private Pilot (Revision E ed.). King Schools, Inc. 2006. pp. 4–16.
  5. ^ a b "Change of German VFR transponder codes A/C 7000 replaces A/C 0021 and A/C 0022". SkyControl Aviation & Aerospace News. 2007-11-06. Archived from the original on 2009-07-14. Retrieved 2018-07-16.
  6. ^ a b c d e f g h i j Australian AIP ENR 1.6 para 7.1.4
  7. ^ a b c d e f g h Transport Canada (2020-03-26). "TP 14371 – Transport Canada Aeronautical Information Manual (TC AIM) – Communications (COM) 8.0".
  8. ^ FAA Order/Publication: 7110.65U dated 2011-ß5-18
  9. ^ FAA Order/Publication: 7110.65V dated 2014-02-19
  10. ^ Transport Canada. "Aviation Safety Flyer Issue 2/2017" (PDF).
  11. ^ a b FAA order JO 7110.65U
  12. ^ a b EASA SERA.13005
  13. ^ a b "FAA Order 7110.65R (Air Traffic Control procedural manual) chapter 5.2, Beacon Systems". Federal Aviation Authority. 2008-01-21.
  14. ^ "DZ Transponder Codes/Separations Flashcards". quizlet.com. Retrieved 2016-07-21.
  15. ^ FAA (11 October 2016). "Notice" (PDF). faa.gov. Archived (PDF) from the original on 2 January 2020. Retrieved 14 March 2022.
  16. ^ "Enr 1.6 Ats Surveillance Services and Procedures". 19 December 2019.
  17. ^ Australian AIP ENR 1.6 para 6.4.6
  18. ^ "SIB", Encyclopedia of Clinical Neuropsychology, New York, NY: Springer New York, 2011, p. 2293, doi:10.1007/978-0-387-79948-3_5102, ISBN 978-0-387-79947-6, retrieved 2024-09-16
  19. ^ "Aeronautical Information Manual, chapter 4 – Air Traffic Control". Federal Aviation Administration. 2007-11-06.