sensors Mode-S transponder

AC4237

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8894Q · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC4237
Octal
53041067
Decimal
11,289,143
Country
US
Tail
N8894Q
Type
B38M
No current signal · last broadcast 22h ago
Flights observed
17
Distinct callsigns
9
Country
US
Last broadcast
22h ago

Last known position

Most recent position reported by Mode-S AC4237.

Country allocation

The ICAO 24-bit address AC4237 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
SWA653 - 4 2026-04-13
SWA2561 - 3 2026-04-13
SWA2144 - 2 2026-04-13
SWA2032 - 2 2026-04-13
SWA1806 - 2 2026-04-13
SWA2681 - 1 2026-04-13
SWA2238 - 1 2026-04-13
SWA1429 - 1 2026-04-12
SWA138 - 1 2026-04-14

Recent flights last 17

DateFlightRouteTakeoffLandingDuration
2026-04-14 SWA138 - Apr 14, 05:15 UTCApr 14, 05:45 UTC30m
2026-04-13 SWA2238 - Apr 13, 23:05 UTCApr 14, 01:20 UTC2h 15m
2026-04-13 SWA2144 BNA → BUF Apr 13, 20:38 UTCApr 13, 22:10 UTC1h 32m
2026-04-13 SWA2144 BNA → BUF Apr 13, 20:50 UTCApr 13, 22:15 UTC1h 25m
2026-04-13 SWA1806 - Apr 13, 17:11 UTCApr 13, 19:27 UTC2h 16m
2026-04-13 SWA1806 - Apr 13, 17:12 UTCApr 13, 19:28 UTC2h 16m
2026-04-13 SWA653 - Apr 13, 16:15 UTCApr 13, 16:25 UTC10m
2026-04-13 SWA653 - Apr 13, 15:50 UTCApr 13, 16:25 UTC35m
2026-04-13 SWA653 - Apr 13, 15:15 UTCApr 13, 16:14 UTC59m
2026-04-13 SWA653 - Apr 13, 15:28 UTCApr 13, 16:22 UTC54m
2026-04-13 SWA2561 - Apr 13, 12:46 UTCApr 13, 14:14 UTC1h 28m
2026-04-13 SWA2561 - Apr 13, 12:46 UTCApr 13, 14:08 UTC1h 22m
2026-04-13 SWA2561 OKC → MDW Apr 13, 10:10 UTCApr 13, 11:45 UTC1h 35m
2026-04-13 SWA2681 LAS → OKC Apr 13, 05:05 UTCApr 13, 07:05 UTC2h 0m
2026-04-13 SWA2032 - Apr 13, 00:20 UTCApr 13, 03:50 UTC3h 30m
2026-04-12 SWA2032 - Apr 12, 23:55 UTCApr 13, 03:50 UTC3h 55m
2026-04-12 SWA1429 - Apr 12, 18:28 UTCApr 12, 19:26 UTC58m

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 N8894Q page for operator, model, and routing details .

Mode-S AC4237 frequently asked

What is Mode-S code AC4237?
AC4237 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8894Q.
Where is Mode-S AC4237 registered?
Mode-S code AC4237 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 AC4237 broadcasting right now?
No active broadcast right now. Last signal was 22h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC4237, octal 53041067, decimal 11,289,143.
What flights does AC4237 operate?
Mode-S AC4237 has broadcast 9 distinct callsigns, including SWA653, SWA2561, SWA2144, SWA2032, SWA1806.