sensors Mode-S transponder

AC481D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8903H · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC481D
Octal
53044035
Decimal
11,290,653
Country
US
Tail
N8903H
Type
B38M
No current signal · last broadcast 20h ago
Flights observed
14
Distinct callsigns
9
Country
US
Last broadcast
20h ago

Last known position

Most recent position reported by Mode-S AC481D.

Country allocation

The ICAO 24-bit address AC481D 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 9 distinct

Callsign Airline Flights Last seen
SWA336 - 3 2026-04-13
SWA3572 Southwest Airlines 2 2026-04-13
SWA3464 - 2 2026-04-13
SWA1974 - 2 2026-04-13
SWA717 - 1 2026-04-13
SWA455 - 1 2026-04-13
SWA3866 Southwest Airlines 1 2026-04-14
SWA3138 - 1 2026-04-12
SWA1295 - 1 2026-04-13

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-04-14 SWA3866 BNA → DAL Apr 14, 05:15 UTCApr 14, 05:30 UTC15m
2026-04-13 SWA1295 - Apr 13, 23:01 UTCApr 14, 01:57 UTC2h 56m
2026-04-13 SWA717 - Apr 13, 20:48 UTCApr 13, 22:04 UTC1h 16m
2026-04-13 SWA1974 - Apr 13, 18:27 UTCApr 13, 19:43 UTC1h 16m
2026-04-13 SWA1974 - Apr 13, 18:33 UTCApr 13, 19:42 UTC1h 9m
2026-04-13 SWA336 - Apr 13, 16:15 UTCApr 13, 17:35 UTC1h 20m
2026-04-13 SWA336 - Apr 13, 15:50 UTCApr 13, 17:35 UTC1h 45m
2026-04-13 SWA336 - Apr 13, 15:33 UTCApr 13, 17:29 UTC1h 56m
2026-04-13 SWA455 - Apr 13, 12:20 UTCApr 13, 14:30 UTC2h 10m
2026-04-13 SWA3464 LAS → MDW Apr 13, 04:25 UTCApr 13, 07:10 UTC2h 45m
2026-04-13 SWA3464 LAS → LAS Apr 13, 03:39 UTCApr 13, 06:49 UTC3h 10m
2026-04-13 SWA3572 TPA → BWI Apr 13, 00:17 UTCApr 13, 03:03 UTC2h 46m
2026-04-13 SWA3572 TPA → BWI Apr 13, 00:33 UTCApr 13, 03:09 UTC2h 36m
2026-04-12 SWA3138 - Apr 12, 17:15 UTCApr 12, 19:55 UTC2h 40m

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 N8903H page for operator, model, and routing details .

Mode-S AC481D frequently asked

What is Mode-S code AC481D?
AC481D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8903H.
Where is Mode-S AC481D registered?
Mode-S code AC481D 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 AC481D broadcasting right now?
No active broadcast right now. Last signal was 20h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC481D, octal 53044035, decimal 11,290,653.
What flights does AC481D operate?
Mode-S AC481D has broadcast 9 distinct callsigns, including SWA336, SWA3572, SWA3464, SWA1974, SWA717.