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sensors Mode-S transponder

AC4F4C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8921Q · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC4F4C
Octal
53047514
Decimal
11,292,492
Country
US
Tail
N8921Q
Type
B38M
No current signal · last broadcast 1h ago
Flights observed
644
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S AC4F4C.

Country allocation

The ICAO 24-bit address AC4F4C 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
SWA4084 Southwest Airlines 6 2026-06-27
SWA3780 Southwest Airlines 5 2026-06-03
SWA1644 Southwest Airlines 5 2026-05-13
SWA4501 Southwest Airlines 4 2026-05-23
SWA426 - 4 2026-07-06
SWA4101 Southwest Airlines 4 2026-05-22
SWA3886 - 4 2026-06-28
SWA314 - 4 2026-06-24
SWA2766 - 4 2026-04-13
SWA164 - 4 2026-06-27
SWA1409 Southwest Airlines 4 2026-05-23
SWA1322 - 4 2026-06-23
SWA1158 Southwest Airlines 4 2026-05-06
SWA974 - 3 2026-07-06
SWA737 Southwest Airlines 3 2026-06-08
SWA555 Southwest Airlines 3 2026-06-01
SWA4457 Southwest Airlines 3 2026-06-27
SWA4322 Southwest Airlines 3 2026-06-15
SWA4203 Southwest Airlines 3 2026-05-26
SWA4102 Southwest Airlines 3 2026-05-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 SWA4229 - Jul 14, 00:45 UTCJul 14, 01:00 UTC15m
2026-07-13 SWA2417 - Jul 13, 23:00 UTCJul 13, 23:45 UTC45m
2026-07-13 SWA4978 OAK → LAX Jul 13, 20:36 UTCJul 13, 21:37 UTC1h 1m
2026-07-13 SWA4978 OAK → LAX Jul 13, 20:40 UTCJul 13, 21:35 UTC55m
2026-07-13 SWA322 LAS → OAK Jul 13, 18:25 UTCJul 13, 19:30 UTC1h 5m
2026-07-13 SWA322 LAS → OAK Jul 13, 18:25 UTCJul 13, 19:26 UTC1h 1m
2026-07-13 SWA322 AUS → LAS Jul 13, 14:35 UTCJul 13, 16:55 UTC2h 20m
2026-07-13 SWA2528 - Jul 13, 12:15 UTCJul 13, 13:35 UTC1h 20m
2026-07-13 SWA2528 MCI → AUS Jul 13, 12:09 UTCJul 13, 13:30 UTC1h 21m
2026-07-13 SWA563 - Jul 13, 05:55 UTCJul 13, 07:01 UTC1h 5m
2026-07-13 SWA2437 - Jul 13, 03:30 UTCJul 13, 04:45 UTC1h 15m
2026-07-13 SWA2437 PIT → BNA Jul 13, 03:30 UTCJul 13, 04:40 UTC1h 10m
2026-07-12 SWA3451 - Jul 12, 23:50 UTCJul 13, 01:45 UTC1h 55m
2026-07-12 SWA1622 - Jul 12, 20:15 UTCJul 12, 22:15 UTC2h 0m
2026-07-12 SWA1622 PIT → MCO Jul 12, 20:13 UTCJul 12, 22:10 UTC1h 58m
2026-07-12 SWA3379 MCO → PIT Jul 12, 15:20 UTCJul 12, 17:15 UTC1h 55m
2026-07-10 SWA1595 - Jul 10, 22:20 UTCJul 11, 01:20 UTC3h 0m
2026-07-10 SWA2967 MSP → DEN Jul 10, 19:08 UTCJul 10, 20:38 UTC1h 31m
2026-07-10 SWA2967 MSP → DEN Jul 10, 19:10 UTCJul 10, 20:45 UTC1h 35m
2026-07-10 SWA3973 DEN → MSP Jul 10, 16:35 UTCJul 10, 18:00 UTC1h 25m
2026-07-10 SWA2454 LGA → DEN Jul 10, 11:25 UTCJul 10, 14:55 UTC3h 30m
2026-07-10 SWA4480 DEN → LGA Jul 10, 01:15 UTCJul 10, 04:45 UTC3h 30m
2026-07-09 SWA3146 POC → DEN Jul 9, 20:15 UTCJul 9, 22:30 UTC2h 15m
2026-07-09 SWA4080 DEN → ONT Jul 9, 17:20 UTCJul 9, 19:10 UTC1h 50m
2026-07-09 SWA3112 OKC → DEN Jul 9, 14:50 UTCJul 9, 16:05 UTC1h 15m
2026-07-09 SWA4490 - Jul 9, 12:35 UTCJul 9, 13:40 UTC1h 5m
2026-07-09 SWA4023 LAS → RNO Jul 9, 09:40 UTCJul 9, 11:30 UTC1h 50m
2026-07-09 SWA4023 LAS → RNO Jul 9, 09:39 UTCJul 9, 11:32 UTC1h 54m
2026-07-08 SWA3844 LAS → TPA Jul 8, 21:20 UTCJul 9, 01:15 UTC3h 55m
2026-07-08 SWA439 - Jul 8, 16:30 UTCJul 8, 19:50 UTC3h 20m
2026-07-08 SWA1969 - Jul 8, 14:00 UTCJul 8, 15:30 UTC1h 30m
2026-07-08 SWA3230 - Jul 8, 03:50 UTCJul 8, 05:15 UTC1h 25m
2026-07-08 SWA1067 - Jul 8, 00:20 UTCJul 8, 02:05 UTC1h 45m
2026-07-07 SWA185 ATL → LGA Jul 7, 21:00 UTCJul 7, 23:20 UTC2h 20m
2026-07-07 SWA185 ATL → LGA Jul 7, 17:35 UTCJul 7, 19:30 UTC1h 55m
2026-07-07 SWA185 ATL → LGA Jul 7, 14:45 UTCJul 7, 16:15 UTC1h 30m
2026-07-07 SWA208 ONT → SMF Jul 7, 04:00 UTCJul 7, 05:00 UTC1h 0m
2026-07-07 SWA208 LAS → ONT Jul 7, 02:35 UTCJul 7, 03:10 UTC35m
2026-07-07 SWA2187 - Jul 7, 00:05 UTCJul 7, 00:50 UTC45m
2026-07-06 SWA3832 SJC → LAX Jul 6, 22:00 UTCJul 6, 23:10 UTC1h 10m
2026-07-06 SWA4533 LAS → SMF Jul 6, 19:50 UTCJul 6, 20:55 UTC1h 5m
2026-07-06 SWA4533 LAS → SMF Jul 6, 19:48 UTCJul 6, 20:51 UTC1h 3m
2026-07-06 SWA974 - Jul 6, 13:55 UTCJul 6, 18:15 UTC4h 20m
2026-07-06 SWA974 - Jul 6, 10:40 UTCJul 6, 12:40 UTC2h 0m
2026-07-06 SWA426 - Jul 6, 02:50 UTCJul 6, 03:00 UTC10m
2026-07-06 SWA426 BWI → MIA Jul 6, 02:48 UTCJul 6, 04:53 UTC2h 6m
2026-07-05 SWA426 BOS → BWI Jul 5, 21:44 UTCJul 5, 23:00 UTC1h 16m
2026-07-05 SWA426 BOS → BWI Jul 5, 21:45 UTCJul 5, 23:00 UTC1h 15m
2026-07-05 SWA4760 MSY → DAL Jul 5, 19:30 UTCJul 5, 20:25 UTC55m
2026-07-05 SWA197 - Jul 5, 16:35 UTCJul 5, 18:00 UTC1h 25m

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 N8921Q page for operator, model, and routing details .

Mode-S AC4F4C frequently asked

What is Mode-S code AC4F4C?
AC4F4C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8921Q.
Where is Mode-S AC4F4C registered?
Mode-S code AC4F4C 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 AC4F4C broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC4F4C, octal 53047514, decimal 11,292,492.
What flights does AC4F4C operate?
Mode-S AC4F4C has broadcast 20 distinct callsigns, including SWA4084, SWA3780, SWA1644, SWA4501, SWA426.