sensors Mode-S transponder

AC2F18

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8840Q · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC2F18
Octal
53027430
Decimal
11,284,248
Country
US
Tail
N8840Q
Type
B38M
Transponder active on ground
Flights observed
16
Distinct callsigns
8
Country
US
Last broadcast
15h ago

Last known position

Most recent position reported by Mode-S AC2F18.

Country allocation

The ICAO 24-bit address AC2F18 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
SWA1399 - 4 2026-04-13
SWA2635 - 3 2026-04-13
SWA1938 - 3 2026-04-14
SWA3826 - 2 2026-04-13
SWA4532 - 1 2026-04-13
SWA420 - 1 2026-04-12
SWA4162 Southwest Airlines 1 2026-04-12
SWA1558 - 1 2026-04-13

Recent flights last 16

DateFlightRouteTakeoffLandingDuration
2026-04-14 SWA1938 - Apr 14, 07:10 UTCApr 14, 08:55 UTC1h 45m
2026-04-14 SWA1938 - Apr 14, 06:04 UTCApr 14, 09:20 UTC3h 16m
2026-04-14 SWA1938 - Apr 14, 05:55 UTCApr 14, 09:02 UTC3h 7m
2026-04-13 SWA1558 - Apr 13, 21:12 UTCApr 14, 00:15 UTC3h 3m
2026-04-13 SWA2635 - Apr 13, 19:50 UTCApr 13, 20:00 UTC10m
2026-04-13 SWA2635 - Apr 13, 16:50 UTCApr 13, 20:09 UTC3h 19m
2026-04-13 SWA2635 - Apr 13, 16:45 UTCApr 13, 19:59 UTC3h 14m
2026-04-13 SWA4532 DEN → LGA Apr 13, 12:25 UTCApr 13, 15:30 UTC3h 5m
2026-04-13 SWA1399 - Apr 13, 04:20 UTCApr 13, 05:40 UTC1h 20m
2026-04-13 SWA1399 - Apr 13, 03:55 UTCApr 13, 05:40 UTC1h 45m
2026-04-13 SWA1399 - Apr 13, 03:12 UTCApr 13, 05:28 UTC2h 16m
2026-04-13 SWA1399 - Apr 13, 03:30 UTCApr 13, 05:38 UTC2h 8m
2026-04-13 SWA3826 - Apr 13, 00:25 UTCApr 13, 02:20 UTC1h 55m
2026-04-13 SWA3826 - Apr 13, 00:00 UTCApr 13, 02:20 UTC2h 20m
2026-04-12 SWA4162 CMH → MDW Apr 12, 19:48 UTCApr 12, 21:57 UTC2h 9m
2026-04-12 SWA420 - Apr 12, 17:15 UTCApr 12, 18:35 UTC1h 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 N8840Q page for operator, model, and routing details .

Mode-S AC2F18 frequently asked

What is Mode-S code AC2F18?
AC2F18 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8840Q.
Where is Mode-S AC2F18 registered?
Mode-S code AC2F18 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 AC2F18 broadcasting right now?
Mode-S AC2F18 is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC2F18, octal 53027430, decimal 11,284,248.
What flights does AC2F18 operate?
Mode-S AC2F18 has broadcast 8 distinct callsigns, including SWA1399, SWA2635, SWA1938, SWA3826, SWA4532.