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 16h ago
Flights observed
19
Distinct callsigns
8
Country
US
Last broadcast
16h 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 8 distinct

Callsign Airline Flights Last seen
SWA2766 - 4 2026-04-13
SWA3521 - 3 2026-04-13
SWA3517 - 3 2026-04-13
SWA2828 - 3 2026-04-13
SWA4190 - 2 2026-04-13
SWA2598 - 2 2026-04-14
SWA2159 Southwest Airlines 1 2026-04-13
SWA1300 - 1 2026-04-13

Recent flights last 19

DateFlightRouteTakeoffLandingDuration
2026-04-14 SWA2598 - Apr 14, 05:17 UTCApr 14, 06:50 UTC1h 33m
2026-04-14 SWA2598 PHX → SJC Apr 14, 05:36 UTCApr 14, 07:12 UTC1h 36m
2026-04-13 SWA2159 BWI → DAL Apr 13, 22:55 UTCApr 13, 23:56 UTC1h 1m
2026-04-13 SWA2766 - Apr 13, 20:00 UTCApr 13, 21:55 UTC1h 55m
2026-04-13 SWA2766 - Apr 13, 19:45 UTCApr 13, 19:55 UTC10m
2026-04-13 SWA2766 - Apr 13, 19:13 UTCApr 13, 21:39 UTC2h 26m
2026-04-13 SWA2766 - Apr 13, 19:43 UTCApr 13, 21:57 UTC2h 14m
2026-04-13 SWA4190 - Apr 13, 16:25 UTCApr 13, 18:09 UTC1h 44m
2026-04-13 SWA4190 - Apr 13, 16:14 UTCApr 13, 17:55 UTC1h 41m
2026-04-13 SWA1300 TPA → SDF Apr 13, 13:33 UTCApr 13, 15:29 UTC1h 56m
2026-04-13 SWA3517 - Apr 13, 12:20 UTCApr 13, 12:35 UTC15m
2026-04-13 SWA3517 - Apr 13, 11:55 UTCApr 13, 12:35 UTC40m
2026-04-13 SWA3517 - Apr 13, 11:20 UTCApr 13, 12:15 UTC55m
2026-04-13 SWA2828 LAS → MSY Apr 13, 04:34 UTCApr 13, 07:32 UTC2h 58m
2026-04-13 SWA2828 - Apr 13, 03:53 UTCApr 13, 06:53 UTC3h 0m
2026-04-13 SWA2828 ONT → LAS Apr 13, 02:50 UTCApr 13, 03:30 UTC40m
2026-04-13 SWA3521 - Apr 13, 01:20 UTCApr 13, 01:45 UTC25m
2026-04-13 SWA3521 - Apr 13, 00:26 UTCApr 13, 01:01 UTC35m
2026-04-12 SWA3521 - Apr 12, 17:15 UTCApr 12, 19:35 UTC2h 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 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 16h 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 8 distinct callsigns, including SWA2766, SWA3521, SWA3517, SWA2828, SWA4190.