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sensors Mode-S transponder

AC3731

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8865L · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC3731
Octal
53033461
Decimal
11,286,321
Country
US
Tail
N8865L
Type
B38M
No current signal · last broadcast 1h ago
Flights observed
602
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S AC3731.

Country allocation

The ICAO 24-bit address AC3731 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
SWA995 Southwest Airlines 4 2026-04-15
SWA875 Southwest Airlines 4 2026-06-09
SWA4220 - 4 2026-07-10
SWA4195 - 4 2026-07-05
SWA3004 - 4 2026-07-01
SWA963 Southwest Airlines 3 2026-06-09
SWA752 Southwest Airlines 3 2026-05-15
SWA555 - 3 2026-04-13
SWA4698 - 3 2026-07-09
SWA4376 - 3 2026-06-27
SWA4113 - 3 2026-06-27
SWA398 Southwest Airlines 3 2026-05-28
SWA3635 - 3 2026-04-13
SWA3514 Southwest Airlines 3 2026-05-17
SWA3296 Southwest Airlines 3 2026-05-19
SWA3038 Southwest Airlines 3 2026-06-15
SWA295 - 3 2026-07-13
SWA2874 Southwest Airlines 3 2026-05-10
SWA2611 Southwest Airlines 3 2026-05-28
SWA2570 - 3 2026-06-28

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 SWA4221 - Jul 14, 23:50 UTCJul 15, 01:20 UTC1h 30m
2026-07-14 SWA3123 OKC → MDW Jul 14, 20:10 UTCJul 14, 21:45 UTC1h 35m
2026-07-14 SWA1071 MCO → OKC Jul 14, 16:45 UTCJul 14, 19:05 UTC2h 20m
2026-07-14 SWA364 AUS → MCO Jul 14, 12:53 UTCJul 14, 15:06 UTC2h 13m
2026-07-14 SWA364 AUS → MCO Jul 14, 12:55 UTCJul 14, 15:05 UTC2h 10m
2026-07-14 SWA4463 DEN → AUS Jul 14, 02:30 UTCJul 14, 04:10 UTC1h 40m
2026-07-13 SWA290 AUS → DEN Jul 13, 23:35 UTCJul 14, 01:20 UTC1h 45m
2026-07-13 SWA290 AUS → DEN Jul 13, 23:31 UTCJul 14, 01:15 UTC1h 45m
2026-07-13 SWA1784 - Jul 13, 20:20 UTCJul 13, 22:05 UTC1h 45m
2026-07-13 SWA295 AUS → ECP Jul 13, 17:55 UTCJul 13, 19:25 UTC1h 30m
2026-07-13 SWA295 OKC → AUS Jul 13, 16:05 UTCJul 13, 17:00 UTC55m
2026-07-13 SWA295 BNA → OKC Jul 13, 13:45 UTCJul 13, 15:05 UTC1h 20m
2026-07-13 SWA4393 - Jul 13, 02:50 UTCJul 13, 04:20 UTC1h 30m
2026-07-13 SWA4393 HOU → BNA Jul 13, 02:50 UTCJul 13, 04:17 UTC1h 27m
2026-07-12 SWA2940 - Jul 12, 20:55 UTCJul 12, 23:55 UTC3h 0m
2026-07-12 SWA3938 - Jul 12, 17:01 UTCJul 12, 19:30 UTC2h 30m
2026-07-12 SWA3944 - Jul 12, 13:30 UTCJul 12, 15:35 UTC2h 5m
2026-07-12 SWA621 SJC → BWI Jul 12, 04:55 UTCJul 12, 09:40 UTC4h 45m
2026-07-12 SWA4936 - Jul 12, 02:25 UTCJul 12, 03:15 UTC50m
2026-07-12 SWA3833 SMF → SNA Jul 12, 00:01 UTCJul 12, 01:06 UTC1h 5m
2026-07-12 SWA3833 - Jul 12, 00:01 UTCJul 12, 01:10 UTC1h 10m
2026-07-11 SWA4538 - Jul 11, 22:05 UTCJul 11, 23:10 UTC1h 5m
2026-07-11 SWA4538 SAN → SMF Jul 11, 22:04 UTCJul 11, 23:10 UTC1h 6m
2026-07-11 SWA3503 DEN → SAN Jul 11, 19:00 UTCJul 11, 20:55 UTC1h 55m
2026-07-11 SWA4394 DAL → DEN Jul 11, 16:00 UTCJul 11, 17:35 UTC1h 35m
2026-07-11 SWA4394 DAL → DEN Jul 11, 15:58 UTCJul 11, 17:30 UTC1h 33m
2026-07-11 SWA4741 - Jul 11, 13:45 UTCJul 11, 14:55 UTC1h 10m
2026-07-11 SWA4741 ELP → DAL Jul 11, 13:31 UTCJul 11, 14:56 UTC1h 25m
2026-07-11 SWA2006 - Jul 11, 11:20 UTCJul 11, 12:15 UTC55m
2026-07-11 SWA2006 AUS → ELP Jul 11, 11:16 UTCJul 11, 12:23 UTC1h 7m
2026-07-11 SWA4902 MSY → AUS Jul 11, 04:05 UTCJul 11, 05:05 UTC1h 0m
2026-07-11 SWA4902 MSY → AUS Jul 11, 04:01 UTCJul 11, 05:03 UTC1h 2m
2026-07-11 SWA4475 - Jul 11, 01:55 UTCJul 11, 03:01 UTC1h 5m
2026-07-10 SWA1957 - Jul 10, 23:15 UTCJul 11, 00:45 UTC1h 30m
2026-07-10 SWA4861 LGA → HOU Jul 10, 18:43 UTCJul 10, 21:51 UTC3h 8m
2026-07-10 SWA4861 - Jul 10, 18:45 UTCJul 10, 21:45 UTC3h 0m
2026-07-10 SWA4044 - Jul 10, 15:05 UTCJul 10, 16:35 UTC1h 30m
2026-07-10 SWA4068 - Jul 10, 11:40 UTCJul 10, 13:20 UTC1h 40m
2026-07-10 SWA4068 MYR → MDW Jul 10, 11:33 UTCJul 10, 13:18 UTC1h 45m
2026-07-10 SWA4220 - Jul 10, 01:35 UTCJul 10, 02:30 UTC55m
2026-07-10 SWA4220 BWI → MYR Jul 10, 01:33 UTCJul 10, 02:33 UTC1h 0m
2026-07-09 SWA4698 - Jul 9, 22:35 UTCJul 10, 00:20 UTC1h 45m
2026-07-09 SWA4698 DEN → MEM Jul 9, 16:53 UTCJul 9, 18:41 UTC1h 48m
2026-07-09 SWA4698 - Jul 9, 16:55 UTCJul 9, 18:40 UTC1h 45m
2026-07-09 SWA239 - Jul 9, 14:00 UTCJul 9, 15:35 UTC1h 35m
2026-07-09 SWA239 - Jul 9, 11:35 UTCJul 9, 13:00 UTC1h 25m
2026-07-09 SWA1347 - Jul 9, 04:05 UTCJul 9, 05:25 UTC1h 20m
2026-07-09 SWA1347 PHX → DAL Jul 9, 01:05 UTCJul 9, 03:05 UTC2h 0m
2026-07-08 SWA3017 MSY → PHX Jul 8, 21:10 UTCJul 9, 00:00 UTC2h 50m
2026-07-08 SWA2295 - Jul 8, 15:55 UTCJul 8, 19:15 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 N8865L page for operator, model, and routing details .

Mode-S AC3731 frequently asked

What is Mode-S code AC3731?
AC3731 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8865L.
Where is Mode-S AC3731 registered?
Mode-S code AC3731 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 AC3731 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 AC3731, octal 53033461, decimal 11,286,321.
What flights does AC3731 operate?
Mode-S AC3731 has broadcast 20 distinct callsigns, including SWA995, SWA875, SWA4220, SWA4195, SWA3004.