Apparatus

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sensors Mode-S transponder

AC56D9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8942L · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC56D9
Octal
53053331
Decimal
11,294,425
Country
US
Tail
N8942L
Type
B38M
No current signal · last broadcast 4h ago
Flights observed
645
Distinct callsigns
20
Country
US
Last broadcast
4h ago

Last known position

Most recent position reported by Mode-S AC56D9.

Country allocation

The ICAO 24-bit address AC56D9 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
SWA1440 - 6 2026-07-11
SWA3855 - 4 2026-04-13
SWA3402 - 4 2026-07-11
SWA2469 Southwest Airlines 4 2026-05-30
SWA946 - 3 2026-07-01
SWA753 - 3 2026-06-17
SWA661 - 3 2026-04-13
SWA4917 Southwest Airlines 3 2026-06-28
SWA483 Southwest Airlines 3 2026-06-04
SWA4515 - 3 2026-07-10
SWA4396 - 3 2026-07-05
SWA4313 Southwest Airlines 3 2026-04-17
SWA424 - 3 2026-07-07
SWA4221 - 3 2026-07-09
SWA3988 Southwest Airlines 3 2026-06-09
SWA3840 - 3 2026-06-23
SWA3710 Southwest Airlines 3 2026-05-30
SWA3677 Southwest Airlines 3 2026-05-29
SWA367 Southwest Airlines 3 2026-05-13
SWA3579 Southwest Airlines 3 2026-06-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 SWA45 - Jul 13, 22:50 UTCJul 13, 23:30 UTC40m
2026-07-13 SWA45 - Jul 13, 19:35 UTCJul 13, 21:50 UTC2h 15m
2026-07-13 SWA4700 - Jul 13, 16:35 UTCJul 13, 18:35 UTC2h 0m
2026-07-13 SWA4274 SMF → DAL Jul 13, 12:15 UTCJul 13, 15:15 UTC3h 0m
2026-07-13 SWA4365 DAL → SMF Jul 13, 02:55 UTCJul 13, 05:50 UTC2h 55m
2026-07-13 SWA4365 DAL → SMF Jul 13, 02:53 UTCJul 13, 05:47 UTC2h 54m
2026-07-12 SWA1403 DCA → DAL Jul 12, 23:00 UTCJul 13, 01:45 UTC2h 45m
2026-07-12 SWA1241 LAS → DCA Jul 12, 16:50 UTCJul 12, 21:35 UTC4h 45m
2026-07-12 SWA1182 - Jul 12, 11:45 UTCJul 12, 14:40 UTC2h 55m
2026-07-12 SWA636 DEN → MDW Jul 12, 02:35 UTCJul 12, 04:35 UTC2h 0m
2026-07-12 SWA636 DEN → MDW Jul 12, 02:34 UTCJul 12, 04:29 UTC1h 55m
2026-07-11 SWA596 CMH → DEN Jul 11, 22:55 UTCJul 12, 01:25 UTC2h 30m
2026-07-11 SWA596 CMH → DEN Jul 11, 22:55 UTCJul 12, 01:22 UTC2h 27m
2026-07-11 SWA3402 - Jul 11, 19:55 UTCJul 11, 21:40 UTC1h 45m
2026-07-11 SWA1440 - Jul 11, 18:50 UTCJul 11, 19:05 UTC15m
2026-07-11 SWA1440 - Jul 11, 17:00 UTCJul 11, 18:15 UTC1h 15m
2026-07-11 SWA1440 DCA → MCO Jul 11, 16:56 UTCJul 11, 18:33 UTC1h 37m
2026-07-11 SWA1440 STL → DCA Jul 11, 14:05 UTCJul 11, 15:40 UTC1h 35m
2026-07-11 SWA1837 - Jul 11, 11:20 UTCJul 11, 12:55 UTC1h 35m
2026-07-11 SWA4808 SAN → CMH Jul 11, 00:13 UTCJul 11, 04:04 UTC3h 51m
2026-07-11 SWA4808 - Jul 11, 00:15 UTCJul 11, 04:05 UTC3h 50m
2026-07-10 SWA3076 - Jul 10, 21:45 UTCJul 10, 22:55 UTC1h 10m
2026-07-10 SWA143 ABQ → OAK Jul 10, 18:45 UTCJul 10, 20:45 UTC2h 0m
2026-07-10 SWA1253 DAL → ABQ Jul 10, 16:20 UTCJul 10, 17:40 UTC1h 20m
2026-07-10 SWA4741 - Jul 10, 13:50 UTCJul 10, 15:05 UTC1h 15m
2026-07-10 SWA4741 ELP → DAL Jul 10, 13:35 UTCJul 10, 15:00 UTC1h 25m
2026-07-10 SWA2006 - Jul 10, 11:15 UTCJul 10, 12:10 UTC55m
2026-07-10 SWA4515 - Jul 10, 03:00 UTCJul 10, 04:40 UTC1h 40m
2026-07-10 SWA4515 STL → AUS Jul 10, 02:59 UTCJul 10, 04:36 UTC1h 37m
2026-07-10 SWA3021 - Jul 10, 00:10 UTCJul 10, 01:35 UTC1h 25m
2026-07-09 SWA1643 DEN → MSY Jul 9, 21:05 UTCJul 9, 23:15 UTC2h 10m
2026-07-09 SWA1346 DAL → DEN Jul 9, 18:25 UTCJul 9, 20:00 UTC1h 35m
2026-07-09 SWA1346 DAL → DEN Jul 9, 18:24 UTCJul 9, 19:55 UTC1h 31m
2026-07-09 SWA1346 - Jul 9, 16:10 UTCJul 9, 17:20 UTC1h 10m
2026-07-09 SWA2668 - Jul 9, 13:50 UTCJul 9, 14:15 UTC25m
2026-07-09 SWA2668 MCO → MSY Jul 9, 13:50 UTCJul 9, 15:13 UTC1h 23m
2026-07-09 SWA3430 - Jul 9, 11:25 UTCJul 9, 12:45 UTC1h 20m
2026-07-09 SWA3430 RDU → MCO Jul 9, 11:22 UTCJul 9, 12:36 UTC1h 14m
2026-07-09 SWA4221 - Jul 9, 00:05 UTCJul 9, 01:40 UTC1h 35m
2026-07-08 SWA1095 LGA → MDW Jul 8, 20:45 UTCJul 8, 22:35 UTC1h 50m
2026-07-08 SWA2813 DEN → LGA Jul 8, 15:33 UTCJul 8, 18:57 UTC3h 25m
2026-07-08 SWA2813 DEN → LGA Jul 8, 15:35 UTCJul 8, 19:00 UTC3h 25m
2026-07-08 SWA2628 MCO → DEN Jul 8, 10:50 UTCJul 8, 14:00 UTC3h 10m
2026-07-08 SWA3728 - Jul 8, 01:30 UTCJul 8, 01:40 UTC10m
2026-07-08 SWA3728 SJU → MCO Jul 8, 01:27 UTCJul 8, 04:01 UTC2h 34m
2026-07-07 SWA424 - Jul 7, 23:35 UTCJul 7, 23:55 UTC20m
2026-07-07 SWA424 - Jul 7, 21:25 UTCJul 7, 22:00 UTC35m
2026-07-07 SWA424 MCO → SJU Jul 7, 21:22 UTCJul 7, 23:47 UTC2h 25m
2026-07-07 SWA2443 MSY → MCO Jul 7, 18:30 UTCJul 7, 19:55 UTC1h 25m
2026-07-07 SWA2443 MSY → MCO Jul 7, 18:26 UTCJul 7, 19:54 UTC1h 28m

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 N8942L page for operator, model, and routing details .

Mode-S AC56D9 frequently asked

What is Mode-S code AC56D9?
AC56D9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8942L.
Where is Mode-S AC56D9 registered?
Mode-S code AC56D9 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 AC56D9 broadcasting right now?
No active broadcast right now. Last signal was 4h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC56D9, octal 53053331, decimal 11,294,425.
What flights does AC56D9 operate?
Mode-S AC56D9 has broadcast 20 distinct callsigns, including SWA1440, SWA3855, SWA3402, SWA2469, SWA946.