Apparatus

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sensors Mode-S transponder

AC20C4

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8804L · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC20C4
Octal
53020304
Decimal
11,280,580
Country
US
Tail
N8804L
Type
B38M
Broadcasting now · callsign SWA3845 · 38,000 ft
Flights observed
695
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 23:00 UTC

Current position

AC20C4 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AC20C4 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
SWA2004 Southwest Airlines 7 2026-05-06
SWA120 Southwest Airlines 7 2026-04-16
SWA2517 - 5 2026-07-07
SWA1351 - 5 2026-07-16
SWA4739 Southwest Airlines 4 2026-07-23
SWA455 Southwest Airlines 4 2026-05-12
SWA3901 - 4 2026-04-13
SWA3457 Southwest Airlines 4 2026-04-16
SWA2877 - 4 2026-07-13
SWA2035 Southwest Airlines 4 2026-05-01
SWA1727 - 4 2026-07-13
SWA1577 Southwest Airlines 4 2026-04-13
SWA1331 - 4 2026-06-27
SWA1048 - 4 2026-07-04
SWA910 Southwest Airlines 3 2026-07-22
SWA8800 - 3 2026-07-12
SWA4653 - 3 2026-07-14
SWA4133 Southwest Airlines 3 2026-05-21
SWA4028 Southwest Airlines 3 2026-07-20
SWA3988 Southwest Airlines 3 2026-06-03

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SWA2769 SJC → AUS Jul 26, 20:55 UTCJul 26, 23:00 UTC2h 5m
2026-07-26 SWA4470 DAL → SJC Jul 26, 18:30 UTCJul 26, 19:30 UTC1h 0m
2026-07-26 SWA4470 DAL → SJC Jul 26, 15:10 UTCJul 26, 17:20 UTC2h 10m
2026-07-26 SWA3526 BDL → MCO Jul 26, 03:42 UTCJul 26, 04:31 UTC49m
2026-07-26 SWA3526 BDL → MCO Jul 26, 03:45 UTCJul 26, 04:35 UTC50m
2026-07-26 SWA4521 BUR → SJC Jul 26, 00:50 UTCJul 26, 02:15 UTC1h 25m
2026-07-25 SWA4944 HOU → STL Jul 25, 22:45 UTCJul 25, 23:45 UTC1h 0m
2026-07-25 SWA721 SJD → DEN Jul 25, 18:11 UTCJul 25, 20:40 UTC2h 29m
2026-07-25 SWA2017 SMF → SJD Jul 25, 14:15 UTCJul 25, 20:45 UTC6h 30m
2026-07-25 SWA636 STL → MDW Jul 25, 05:10 UTCJul 25, 06:40 UTC1h 30m
2026-07-25 SWA555 SMF → PHX Jul 25, 02:20 UTCJul 25, 03:45 UTC1h 25m
2026-07-24 SWA2018 SJD → SMF Jul 24, 22:50 UTCJul 25, 00:15 UTC1h 25m
2026-07-24 SWA3006 HOU → SJD Jul 24, 18:00 UTCJul 24, 19:05 UTC1h 5m
2026-07-24 SWA3006 HOU → SJD Jul 24, 17:55 UTCJul 24, 19:59 UTC2h 4m
2026-07-24 SWA934 BWI → SDF Jul 24, 14:30 UTCJul 24, 15:15 UTC45m
2026-07-24 SWA934 BWI → SDF Jul 24, 12:10 UTCJul 24, 13:20 UTC1h 10m
2026-07-23 SWA4739 MDW → AUS Jul 23, 23:44 UTCJul 24, 02:45 UTC3h 1m
2026-07-23 SWA4739 MDW → AUS Jul 23, 23:45 UTCJul 24, 02:50 UTC3h 5m
2026-07-23 SWA4739 MDW → AUS Jul 23, 22:30 UTCJul 23, 22:50 UTC20m
2026-07-23 SWA3146 MDW → PHL Jul 23, 20:20 UTCJul 23, 22:25 UTC2h 5m
2026-07-23 SWA3146 MDW → PHL Jul 23, 20:16 UTCJul 23, 22:21 UTC2h 6m
2026-07-23 SWA4080 MDW → HOU Jul 23, 17:15 UTCJul 23, 19:00 UTC1h 45m
2026-07-23 SWA3112 LAS → DEN Jul 23, 14:40 UTCJul 23, 15:50 UTC1h 10m
2026-07-23 SWA4490 BWI → JAX Jul 23, 12:40 UTCJul 23, 13:40 UTC1h 0m
2026-07-23 SWA4490 BWI → JAX Jul 23, 12:35 UTCJul 23, 13:36 UTC1h 1m
2026-07-23 SWA4023 LAS → RNO Jul 23, 09:35 UTCJul 23, 11:15 UTC1h 40m
2026-07-23 SWA4739 MDW → AUS Jul 23, 04:40 UTCJul 23, 07:45 UTC3h 5m
2026-07-23 SWA957 OAK → PDX Jul 23, 01:50 UTCJul 23, 03:25 UTC1h 35m
2026-07-22 SWA910 PHX → SAN Jul 22, 19:25 UTCJul 22, 21:45 UTC2h 20m
2026-07-22 SWA910 PHX → SAN Jul 22, 17:35 UTCJul 22, 18:10 UTC35m
2026-07-22 SWA2363 BNA → BOS Jul 22, 13:25 UTCJul 22, 16:30 UTC3h 5m
2026-07-22 SWA2357 - Jul 22, 05:05 UTCJul 22, 05:25 UTC20m
2026-07-22 SWA1161 SAN → OAK Jul 22, 00:45 UTCJul 22, 04:05 UTC3h 20m
2026-07-21 SWA1627 MDW → BOS Jul 21, 21:45 UTCJul 21, 23:35 UTC1h 50m
2026-07-21 SWA3495 - Jul 21, 18:35 UTCJul 21, 20:30 UTC1h 55m
2026-07-21 SWA659 MDW → OMA Jul 21, 13:40 UTCJul 21, 17:15 UTC3h 35m
2026-07-21 SWA3349 PHX → SMF Jul 21, 11:15 UTCJul 21, 11:55 UTC40m
2026-07-21 SWA4435 - Jul 21, 03:05 UTCJul 21, 04:15 UTC1h 10m
2026-07-20 SWA4670 DEN → AUS Jul 20, 22:15 UTCJul 21, 00:25 UTC2h 9m
2026-07-20 SWA4030 - Jul 20, 18:05 UTCJul 20, 19:55 UTC1h 50m
2026-07-20 SWA4029 ORD → BNA Jul 20, 15:00 UTCJul 20, 16:45 UTC1h 45m
2026-07-20 SWA4029 ORD → BNA Jul 20, 14:55 UTCJul 20, 16:45 UTC1h 50m
2026-07-20 SWA4028 AUS → TPA Jul 20, 11:35 UTCJul 20, 13:40 UTC2h 5m
2026-07-20 SWA3735 - Jul 20, 05:55 UTCJul 20, 09:30 UTC3h 35m
2026-07-20 SWA4867 - Jul 20, 02:35 UTCJul 20, 03:45 UTC1h 10m
2026-07-20 SWA2603 MSY → DCA Jul 20, 00:45 UTCJul 20, 01:35 UTC50m
2026-07-20 SWA2603 MSY → DCA Jul 20, 00:40 UTCJul 20, 01:28 UTC48m
2026-07-19 SWA882 DAL → DCA Jul 19, 22:40 UTCJul 19, 23:35 UTC55m
2026-07-19 SWA1369 OAK → LGB Jul 19, 18:25 UTCJul 19, 21:15 UTC2h 50m
2026-07-19 SWA2188 DAL → LGA Jul 19, 13:45 UTCJul 19, 17:05 UTC3h 20m

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 N8804L page for operator, model, and routing details .

Mode-S AC20C4 frequently asked

What is Mode-S code AC20C4?
AC20C4 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8804L.
Where is Mode-S AC20C4 registered?
Mode-S code AC20C4 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 AC20C4 broadcasting right now?
Yes. Mode-S AC20C4 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC20C4, octal 53020304, decimal 11,280,580.
What flights does AC20C4 operate?
Mode-S AC20C4 has broadcast 20 distinct callsigns, including SWA2004, SWA120, SWA2517, SWA1351, SWA4739.