Apparatus

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sensors Mode-S transponder

A557C3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N443WN · BOEING 737-700 · operated by SOUTHWEST AIRLINES CO

Hex
A557C3
Octal
51253703
Decimal
10,835,907
Country
US
Tail
N443WN
Type
B737
Broadcasting now · callsign SWA4270 · 22,700 ft
Flights observed
519
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Current position

A557C3 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A557C3 falls within the block assigned to United States (US) by ICAO Annex 10, Volume III. Every aircraft registered in United States receives a permanent address from this block at the time of registration; the address stays with the airframe even if the aircraft is re-registered to a different operator within the country.

Callsign history 20 distinct

Callsign Airline Flights Last seen
SWA3828 - 8 2026-06-30
SWA585 Southwest Airlines 5 2026-06-14
SWA3295 - 5 2026-06-30
SWA1266 Southwest Airlines 5 2026-06-28
SWA1140 Southwest Airlines 5 2026-04-24
SWA711 - 4 2026-06-30
SWA549 Southwest Airlines 4 2026-04-29
SWA406 - 4 2026-06-29
SWA342 - 4 2026-06-18
SWA2990 Southwest Airlines 4 2026-06-03
SWA291 Southwest Airlines 4 2026-06-07
SWA2737 Southwest Airlines 4 2026-05-28
SWA270 - 4 2026-06-27
SWA2414 - 4 2026-07-09
SWA1954 - 4 2026-04-17
SWA165 - 4 2026-07-03
SWA1118 Southwest Airlines 4 2026-04-25
SWA921 - 3 2026-06-26
SWA862 - 3 2026-06-21
SWA803 - 3 2026-07-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 SWA4370 BUR → LAS Jul 14, 01:35 UTCJul 14, 02:20 UTC45m
2026-07-13 SWA697 - Jul 13, 22:55 UTCJul 14, 00:40 UTC1h 45m
2026-07-13 SWA803 HOU → LGB Jul 13, 20:35 UTCJul 13, 21:39 UTC1h 4m
2026-07-13 SWA803 - Jul 13, 20:35 UTCJul 13, 21:40 UTC1h 5m
2026-07-13 SWA803 BUR → OAK Jul 13, 18:40 UTCJul 13, 19:30 UTC50m
2026-07-13 SWA2198 LAS → BUR Jul 13, 16:50 UTCJul 13, 17:45 UTC55m
2026-07-13 SWA4296 - Jul 13, 15:00 UTCJul 13, 15:45 UTC45m
2026-07-13 SWA3204 - Jul 13, 04:00 UTCJul 13, 05:10 UTC1h 10m
2026-07-13 SWA4032 LAS → SMF Jul 13, 02:05 UTCJul 13, 03:05 UTC1h 0m
2026-07-13 SWA4032 LAS → SMF Jul 13, 02:05 UTCJul 13, 03:10 UTC1h 5m
2026-07-12 SWA1162 SJC → LAS Jul 12, 23:40 UTCJul 13, 00:45 UTC1h 5m
2026-07-12 SWA3539 - Jul 12, 22:00 UTCJul 12, 22:55 UTC55m
2026-07-12 SWA3539 SAN → SJC Jul 12, 21:57 UTCJul 12, 22:52 UTC55m
2026-07-12 SWA1532 SMF → SAN Jul 12, 19:30 UTCJul 12, 20:45 UTC1h 15m
2026-07-12 SWA1532 EUG → SMF Jul 12, 17:25 UTCJul 12, 18:25 UTC1h 0m
2026-07-12 SWA1532 DEN → EUG Jul 12, 14:05 UTCJul 12, 16:20 UTC2h 15m
2026-07-12 SWA1177 - Jul 12, 11:50 UTCJul 12, 12:10 UTC20m
2026-07-12 SWA4036 LAS → COS Jul 12, 02:05 UTCJul 12, 03:30 UTC1h 25m
2026-07-12 SWA3124 BUR → LAS Jul 12, 00:01 UTCJul 12, 00:45 UTC45m
2026-07-12 SWA3124 BUR → LAS Jul 12, 00:00 UTCJul 12, 00:38 UTC38m
2026-07-11 SWA113 LAS → BUR Jul 11, 21:40 UTCJul 11, 22:25 UTC45m
2026-07-11 SWA3866 - Jul 11, 16:50 UTCJul 11, 18:45 UTC1h 55m
2026-07-11 SWA3866 MCI → LAS Jul 11, 16:45 UTCJul 11, 19:11 UTC2h 26m
2026-07-11 SWA4387 - Jul 11, 02:40 UTCJul 11, 03:45 UTC1h 5m
2026-07-10 SWA2961 - Jul 10, 23:50 UTCJul 11, 01:35 UTC1h 45m
2026-07-10 SWA2961 MDW → DAL Jul 10, 23:49 UTCJul 11, 01:34 UTC1h 45m
2026-07-10 SWA3345 - Jul 10, 21:15 UTCJul 10, 22:30 UTC1h 15m
2026-07-10 SWA3345 - Jul 10, 18:45 UTCJul 10, 20:20 UTC1h 35m
2026-07-10 SWA3375 - Jul 10, 14:20 UTCJul 10, 16:10 UTC1h 50m
2026-07-10 SWA3375 PIT → MCO Jul 10, 14:15 UTCJul 10, 16:02 UTC1h 47m
2026-07-10 SWA4041 - Jul 10, 11:05 UTCJul 10, 13:00 UTC1h 55m
2026-07-10 SWA4494 LAS → TPA Jul 10, 00:50 UTCJul 10, 04:50 UTC4h 0m
2026-07-09 SWA2414 LGB → LAS Jul 9, 22:30 UTCJul 9, 23:15 UTC45m
2026-07-09 SWA2414 SMF → LGB Jul 9, 20:10 UTCJul 9, 21:15 UTC1h 5m
2026-07-09 SWA1740 DEN → SMF Jul 9, 17:10 UTCJul 9, 19:15 UTC2h 5m
2026-07-09 SWA3493 - Jul 9, 14:15 UTCJul 9, 16:05 UTC1h 50m
2026-07-09 SWA1089 - Jul 9, 01:50 UTCJul 9, 06:30 UTC4h 40m
2026-07-08 SWA3983 - Jul 8, 23:25 UTCJul 9, 00:25 UTC1h 0m
2026-07-08 SWA1375 - Jul 8, 21:00 UTCJul 8, 21:55 UTC55m
2026-07-08 SWA158 ABQ → BWI Jul 8, 16:15 UTCJul 8, 19:40 UTC3h 25m
2026-07-08 SWA284 - Jul 8, 13:20 UTCJul 8, 15:00 UTC1h 40m
2026-07-08 SWA3267 - Jul 8, 09:30 UTCJul 8, 11:55 UTC2h 25m
2026-07-08 SWA3267 PIT → HOU Jul 8, 09:26 UTCJul 8, 11:58 UTC2h 33m
2026-07-08 SWA2210 - Jul 8, 00:35 UTCJul 8, 02:20 UTC1h 45m
2026-07-07 SWA5063 BNA → BWI Jul 7, 20:55 UTCJul 7, 23:15 UTC2h 20m
2026-07-07 SWA5062 DAL → MCO Jul 7, 17:45 UTCJul 7, 19:50 UTC2h 5m
2026-07-07 SWA4889 LAS → MCO Jul 7, 12:15 UTCJul 7, 16:30 UTC4h 15m
2026-07-07 SWA1567 - Jul 7, 04:30 UTCJul 7, 05:55 UTC1h 25m
2026-07-07 SWA670 - Jul 7, 01:20 UTCJul 7, 03:05 UTC1h 45m
2026-07-06 SWA670 - Jul 6, 23:35 UTCJul 7, 00:35 UTC1h 0m

About Mode-S

A Mode-S transponder code (also called an "ICAO 24-bit address" or "hex code") is a 6-character hexadecimal identifier permanently assigned to an aircraft when it's first registered. Unlike callsigns (which change with each flight) or registrations (which can change if an aircraft is sold internationally), the Mode-S address stays with the airframe for the life of the aircraft in that country.

Every ADS-B transmission from an aircraft includes its Mode-S address, making it the most reliable way to identify a specific airframe. Flight-tracking services like Apparatus use the Mode-S address as the primary key for tying position broadcasts, callsigns, and ownership records together.

Prefer a tail-number view? See the N443WN page for operator, model, and routing details .

Mode-S A557C3 frequently asked

What is Mode-S code A557C3?
A557C3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N443WN.
Where is Mode-S A557C3 registered?
Mode-S code A557C3 is allocated to United States (US). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is A557C3 broadcasting right now?
Yes. Mode-S A557C3 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A557C3, octal 51253703, decimal 10,835,907.
What flights does A557C3 operate?
Mode-S A557C3 has broadcast 20 distinct callsigns, including SWA3828, SWA585, SWA3295, SWA1266, SWA1140.