应答机代码列表

以下列表展示了在各个国家或地区用于特定目的之航空器应答机代码和代码范围。传统来说，每个国家都通过自己的方案分配转发器代码，不同国家的代码几乎没有共同点。该列表由于历史兴趣而被保留。

飞行员通常需要将空中交通管制分配的代码应用于特定的航班。有时，国家可能会指定在没有分配代码的情况下使用的通用代码。此类通用代码在该国的航空情报手册或航行资料汇编中指定。对于国际民用航空组织（ICAO）定义的特定情况，有标准应答器代码。

下列列表中，以红色显示的应答器代码仅用于紧急情况，例如飞机劫持、无线电通信故障及机上发生紧急状况等。

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