sensors Mode-S transponder

AC2439

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8812Q · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC2439
Octal
53022071
Decimal
11,281,465
Country
US
Tail
N8812Q
Type
B38M
No current signal · last broadcast 1d ago
Flights observed
14
Distinct callsigns
10
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AC2439.

Country allocation

The ICAO 24-bit address AC2439 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 10 distinct

Callsign Airline Flights Last seen
SWA4376 - 3 2026-04-13
SWA925 - 2 2026-04-13
SWA4044 - 2 2026-04-13
SWA4527 - 1 2026-04-12
SWA3660 - 1 2026-04-12
SWA2488 - 1 2026-04-13
SWA2047 - 1 2026-04-12
SWA1988 - 1 2026-04-13
SWA1556 - 1 2026-04-13
SWA1548 - 1 2026-04-13

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-04-13 SWA1548 - Apr 13, 23:22 UTCApr 14, 01:44 UTC2h 22m
2026-04-13 SWA925 - Apr 13, 19:51 UTCApr 13, 22:24 UTC2h 33m
2026-04-13 SWA925 - Apr 13, 19:51 UTCApr 13, 22:20 UTC2h 29m
2026-04-13 SWA4044 - Apr 13, 16:15 UTCApr 13, 18:50 UTC2h 35m
2026-04-13 SWA4044 - Apr 13, 16:02 UTCApr 13, 18:54 UTC2h 52m
2026-04-13 SWA1988 - Apr 13, 12:35 UTCApr 13, 14:57 UTC2h 22m
2026-04-13 SWA2488 - Apr 13, 10:30 UTCApr 13, 11:35 UTC1h 5m
2026-04-13 SWA4376 - Apr 13, 04:20 UTCApr 13, 05:35 UTC1h 15m
2026-04-13 SWA4376 - Apr 13, 03:38 UTCApr 13, 05:15 UTC1h 37m
2026-04-13 SWA4376 - Apr 13, 04:05 UTCApr 13, 05:34 UTC1h 29m
2026-04-13 SWA1556 - Apr 13, 01:06 UTCApr 13, 02:27 UTC1h 21m
2026-04-12 SWA3660 - Apr 12, 23:55 UTCApr 13, 00:25 UTC30m
2026-04-12 SWA2047 - Apr 12, 19:41 UTCApr 12, 20:55 UTC1h 14m
2026-04-12 SWA4527 - Apr 12, 16:51 UTCApr 12, 18:44 UTC1h 53m

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 N8812Q page for operator, model, and routing details .

Mode-S AC2439 frequently asked

What is Mode-S code AC2439?
AC2439 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8812Q.
Where is Mode-S AC2439 registered?
Mode-S code AC2439 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 AC2439 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC2439, octal 53022071, decimal 11,281,465.
What flights does AC2439 operate?
Mode-S AC2439 has broadcast 10 distinct callsigns, including SWA4376, SWA925, SWA4044, SWA4527, SWA3660.