sensors Mode-S transponder

AC23EF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8810L · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC23EF
Octal
53021757
Decimal
11,281,391
Country
US
Tail
N8810L
Type
B38M
No current signal · last broadcast 23h ago
Flights observed
13
Distinct callsigns
6
Country
US
Last broadcast
23h ago

Last known position

Most recent position reported by Mode-S AC23EF.

Country allocation

The ICAO 24-bit address AC23EF 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 6 distinct

Callsign Airline Flights Last seen
SWA2145 - 5 2026-04-13
SWA2495 Southwest Airlines 3 2026-04-13
SWA4576 - 2 2026-04-13
SWA4594 - 1 2026-04-13
SWA3131 - 1 2026-04-13
SWA2613 - 1 2026-04-12

Recent flights last 13

DateFlightRouteTakeoffLandingDuration
2026-04-13 SWA3131 - Apr 13, 20:52 UTCApr 13, 23:05 UTC2h 13m
2026-04-13 SWA4594 - Apr 13, 18:21 UTCApr 13, 19:46 UTC1h 25m
2026-04-13 SWA2495 SFO → SAN Apr 13, 16:32 UTCApr 13, 17:25 UTC53m
2026-04-13 SWA2495 SFO → SAN Apr 13, 16:32 UTCApr 13, 17:17 UTC45m
2026-04-13 SWA2495 SFO → SAN Apr 13, 13:15 UTCApr 13, 15:25 UTC2h 10m
2026-04-13 SWA4576 - Apr 13, 05:13 UTCApr 13, 06:00 UTC47m
2026-04-13 SWA4576 - Apr 13, 05:55 UTCApr 13, 06:33 UTC38m
2026-04-13 SWA2145 - Apr 13, 04:20 UTCApr 13, 04:40 UTC20m
2026-04-13 SWA2145 - Apr 13, 03:55 UTCApr 13, 04:40 UTC45m
2026-04-13 SWA2145 - Apr 13, 00:03 UTCApr 13, 04:09 UTC4h 6m
2026-04-13 SWA2145 - Apr 13, 00:19 UTCApr 13, 04:16 UTC3h 57m
2026-04-13 SWA2145 - Apr 13, 00:40 UTCApr 13, 04:15 UTC3h 35m
2026-04-12 SWA2613 - Apr 12, 18:30 UTCApr 12, 20:15 UTC1h 45m

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 N8810L page for operator, model, and routing details .

Mode-S AC23EF frequently asked

What is Mode-S code AC23EF?
AC23EF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8810L.
Where is Mode-S AC23EF registered?
Mode-S code AC23EF 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 AC23EF broadcasting right now?
No active broadcast right now. Last signal was 23h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC23EF, octal 53021757, decimal 11,281,391.
What flights does AC23EF operate?
Mode-S AC23EF has broadcast 6 distinct callsigns, including SWA2145, SWA2495, SWA4576, SWA4594, SWA3131.