sensors Mode-S transponder

AC27CF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8821S · operated by SOUTHWEST AIRLINES CO

Hex
AC27CF
Octal
53023717
Decimal
11,282,383
Country
US
Tail
N8821S
Type
B38M
Broadcasting now · callsign SWA2736 · 41,000 ft
Flights observed
16
Distinct callsigns
8
Country
US
Last broadcast
1d ago

Current position

AC27CF is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AC27CF 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
SWA4504 - 3 2026-04-13
SWA3729 - 3 2026-04-13
SWA697 - 2 2026-04-13
SWA3753 - 2 2026-04-13
SWA3345 - 2 2026-04-12
SWA3151 Southwest Airlines 2 2026-04-13
SWA2422 Southwest Airlines 1 2026-04-13
SWA1696 - 1 2026-04-13

Recent flights last 16

DateFlightRouteTakeoffLandingDuration
2026-04-13 SWA1696 - Apr 13, 21:37 UTCApr 14, 00:58 UTC3h 21m
2026-04-13 SWA3729 - Apr 13, 19:50 UTCApr 13, 20:40 UTC50m
2026-04-13 SWA3729 - Apr 13, 18:27 UTCApr 13, 20:19 UTC1h 52m
2026-04-13 SWA3729 - Apr 13, 18:55 UTCApr 13, 20:35 UTC1h 40m
2026-04-13 SWA4504 - Apr 13, 16:15 UTCApr 13, 17:55 UTC1h 40m
2026-04-13 SWA4504 - Apr 13, 16:15 UTCApr 13, 17:55 UTC1h 40m
2026-04-13 SWA4504 - Apr 13, 15:50 UTCApr 13, 17:41 UTC1h 51m
2026-04-13 SWA2422 MKE → MCO Apr 13, 13:35 UTCApr 13, 15:10 UTC1h 35m
2026-04-13 SWA3151 MHT → MCO Apr 13, 03:55 UTCApr 13, 06:10 UTC2h 15m
2026-04-13 SWA3151 MHT → MCO Apr 13, 04:22 UTCApr 13, 06:47 UTC2h 25m
2026-04-13 SWA697 - Apr 13, 02:55 UTCApr 13, 03:05 UTC10m
2026-04-13 SWA697 - Apr 13, 01:23 UTCApr 13, 02:39 UTC1h 16m
2026-04-13 SWA3753 - Apr 13, 00:20 UTCApr 13, 00:55 UTC35m
2026-04-12 SWA3753 - Apr 12, 23:55 UTCApr 13, 00:55 UTC1h 0m
2026-04-12 SWA3345 - Apr 12, 17:11 UTCApr 12, 20:32 UTC3h 21m
2026-04-12 SWA3345 - Apr 12, 17:15 UTCApr 12, 20:44 UTC3h 29m

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 N8821S page for operator, model, and routing details .

Mode-S AC27CF frequently asked

What is Mode-S code AC27CF?
AC27CF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8821S.
Where is Mode-S AC27CF registered?
Mode-S code AC27CF 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 AC27CF broadcasting right now?
Yes. Mode-S AC27CF is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC27CF, octal 53023717, decimal 11,282,383.
What flights does AC27CF operate?
Mode-S AC27CF has broadcast 8 distinct callsigns, including SWA4504, SWA3729, SWA697, SWA3753, SWA3345.