Apparatus

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sensors Mode-S transponder

AC2173

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8809L · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC2173
Octal
53020563
Decimal
11,280,755
Country
US
Tail
N8809L
Type
B38M
No current signal · last broadcast Jul 26, 22:35 UTC
Flights observed
656
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:35 UTC

Last known position

Most recent position reported by Mode-S AC2173.

Country allocation

The ICAO 24-bit address AC2173 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
SWA211 - 5 2026-07-19
SWA899 Southwest Airlines 4 2026-06-10
SWA858 - 4 2026-06-16
SWA855 Southwest Airlines 4 2026-07-25
SWA4331 - 4 2026-07-17
SWA2797 - 4 2026-06-23
SWA2445 - 4 2026-07-14
SWA241 Southwest Airlines 4 2026-05-23
SWA2094 Southwest Airlines 4 2026-04-17
SWA1853 Southwest Airlines 4 2026-04-13
SWA1277 Southwest Airlines 4 2026-06-11
SWA8503 Southwest Airlines 3 2026-05-12
SWA786 Southwest Airlines 3 2026-04-29
SWA660 Southwest Airlines 3 2026-05-01
SWA611 Southwest Airlines 3 2026-07-24
SWA543 Southwest Airlines 3 2026-05-27
SWA497 Southwest Airlines 3 2026-07-20
SWA4943 Southwest Airlines 3 2026-04-14
SWA486 - 3 2026-07-08
SWA4789 - 3 2026-07-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SWA1268 LAS → BLI Jul 26, 20:15 UTCJul 26, 22:35 UTC2h 20m
2026-07-26 SWA1268 LAS → BLI Jul 26, 17:45 UTCJul 26, 18:55 UTC1h 10m
2026-07-26 SWA1268 LAS → BLI Jul 26, 13:20 UTCJul 26, 16:15 UTC2h 55m
2026-07-26 SWA1521 EUG → SJC Jul 26, 00:53 UTCJul 26, 02:20 UTC1h 27m
2026-07-26 SWA1521 EUG → SJC Jul 26, 00:55 UTCJul 26, 02:25 UTC1h 30m
2026-07-25 SWA4105 LAS → DEN Jul 25, 21:47 UTCJul 25, 23:42 UTC1h 55m
2026-07-25 SWA4105 LAS → DEN Jul 25, 21:50 UTCJul 25, 23:45 UTC1h 55m
2026-07-25 SWA855 SNA → OAK Jul 25, 17:15 UTCJul 25, 20:15 UTC3h 0m
2026-07-25 SWA855 SNA → OAK Jul 25, 14:00 UTCJul 25, 16:10 UTC2h 10m
2026-07-25 SWA1686 LAX → LAS Jul 25, 11:35 UTCJul 25, 12:45 UTC1h 10m
2026-07-25 SWA4829 BWI → LGB Jul 25, 02:20 UTCJul 25, 03:35 UTC1h 15m
2026-07-24 SWA284 ATL → DEN Jul 24, 23:00 UTCJul 25, 01:20 UTC2h 20m
2026-07-24 SWA284 ATL → DEN Jul 24, 20:50 UTCJul 24, 21:50 UTC1h 0m
2026-07-24 SWA4470 DAL → SJC Jul 24, 17:35 UTCJul 24, 19:35 UTC2h 0m
2026-07-24 SWA4470 DAL → SJC Jul 24, 14:35 UTCJul 24, 16:40 UTC2h 5m
2026-07-24 SWA4470 DAL → SJC Jul 24, 11:35 UTCJul 24, 13:15 UTC1h 40m
2026-07-24 SWA2554 MHT → BWI Jul 24, 05:55 UTCJul 24, 07:30 UTC1h 35m
2026-07-24 SWA3125 COS → LAS Jul 24, 02:55 UTCJul 24, 04:40 UTC1h 45m
2026-07-24 SWA611 DAL → RSW Jul 24, 00:10 UTCJul 24, 02:10 UTC2h 0m
2026-07-24 SWA611 DAL → RSW Jul 24, 00:05 UTCJul 24, 02:04 UTC1h 59m
2026-07-23 SWA611 DAL → RSW Jul 23, 22:15 UTCJul 23, 23:05 UTC50m
2026-07-23 SWA3623 MHT → MCO Jul 23, 18:40 UTCJul 23, 21:00 UTC2h 20m
2026-07-23 SWA1406 DAL → TPA Jul 23, 13:40 UTCJul 23, 17:20 UTC3h 40m
2026-07-23 SWA1406 DAL → TPA Jul 23, 10:15 UTCJul 23, 12:15 UTC2h 0m
2026-07-23 SWA3731 DEN → BWI Jul 23, 01:20 UTCJul 23, 03:45 UTC2h 25m
2026-07-23 SWA3731 DEN → BWI Jul 23, 01:18 UTCJul 23, 03:44 UTC2h 26m
2026-07-22 SWA424 LGA → TPA Jul 22, 23:45 UTCJul 22, 23:55 UTC10m
2026-07-22 SWA424 LGA → TPA Jul 22, 21:17 UTCJul 22, 23:50 UTC2h 33m
2026-07-22 SWA424 LGA → TPA Jul 22, 21:20 UTCJul 22, 21:55 UTC35m
2026-07-22 SWA783 DAL → OAK Jul 22, 17:25 UTCJul 22, 19:20 UTC1h 55m
2026-07-22 SWA1154 PIT → DEN Jul 22, 12:10 UTCJul 22, 13:50 UTC1h 40m
2026-07-22 SWA1154 PIT → DEN Jul 22, 12:07 UTCJul 22, 15:30 UTC3h 23m
2026-07-22 SWA3705 MCO → MHT Jul 22, 02:35 UTCJul 22, 04:05 UTC1h 30m
2026-07-22 SWA4307 - Jul 22, 00:35 UTCJul 22, 01:20 UTC45m
2026-07-21 SWA3684 LGA → TPA Jul 21, 22:35 UTCJul 21, 23:35 UTC1h 0m
2026-07-21 SWA994 ATL → MDW Jul 21, 20:15 UTCJul 21, 21:40 UTC1h 25m
2026-07-21 SWA4873 MCO → ATL Jul 21, 17:35 UTCJul 21, 19:15 UTC1h 40m
2026-07-21 SWA3824 BNA → DCA Jul 21, 13:40 UTCJul 21, 16:20 UTC2h 40m
2026-07-21 SWA954 - Jul 21, 03:20 UTCJul 21, 05:15 UTC1h 55m
2026-07-21 SWA1251 OAK → BUR Jul 21, 01:30 UTCJul 21, 02:15 UTC45m
2026-07-20 SWA1251 OAK → BUR Jul 20, 22:20 UTCJul 21, 00:40 UTC2h 19m
2026-07-20 SWA2226 PHX → SJC Jul 20, 19:40 UTCJul 20, 21:05 UTC1h 25m
2026-07-20 SWA2226 PHX → SJC Jul 20, 19:36 UTCJul 20, 21:01 UTC1h 25m
2026-07-20 SWA2794 - Jul 20, 15:00 UTCJul 20, 18:00 UTC3h 0m
2026-07-20 SWA1442 DCA → MDW Jul 20, 12:25 UTCJul 20, 13:50 UTC1h 25m
2026-07-20 SWA497 OAK → PSP Jul 20, 03:45 UTCJul 20, 05:05 UTC1h 20m
2026-07-20 SWA497 OAK → PSP Jul 20, 03:44 UTCJul 20, 05:03 UTC1h 20m
2026-07-19 SWA261 DCA → MSY Jul 19, 23:55 UTCJul 20, 01:45 UTC1h 50m
2026-07-19 SWA261 DCA → MSY Jul 19, 22:20 UTCJul 19, 22:50 UTC30m
2026-07-19 SWA211 - Jul 19, 18:15 UTCJul 19, 20:55 UTC2h 40m

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 N8809L page for operator, model, and routing details .

Mode-S AC2173 frequently asked

What is Mode-S code AC2173?
AC2173 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8809L.
Where is Mode-S AC2173 registered?
Mode-S code AC2173 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 AC2173 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 22:35 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC2173, octal 53020563, decimal 11,280,755.
What flights does AC2173 operate?
Mode-S AC2173 has broadcast 20 distinct callsigns, including SWA211, SWA899, SWA858, SWA855, SWA4331.