sensors Mode-S transponder

AC57AF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8948Q · operated by SOUTHWEST AIRLINES CO

Hex
AC57AF
Octal
53053657
Decimal
11,294,639
Country
US
Tail
N8948Q
Type
B38M
Broadcasting now · callsign SWA873 · 37,000 ft
Flights observed
13
Distinct callsigns
6
Country
US
Last broadcast
12h ago

Current position

AC57AF is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AC57AF 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
SWA139 - 4 2026-04-13
SWA3064 - 3 2026-04-13
SWA458 - 2 2026-04-13
SWA3377 - 2 2026-04-12
SWA3002 - 1 2026-04-13
SWA2013 - 1 2026-04-14

Recent flights last 13

DateFlightRouteTakeoffLandingDuration
2026-04-14 SWA2013 - Apr 14, 10:40 UTCApr 14, 11:05 UTC25m
2026-04-13 SWA3064 - Apr 13, 22:00 UTCApr 13, 23:45 UTC1h 45m
2026-04-13 SWA3064 - Apr 13, 19:50 UTCApr 13, 20:50 UTC1h 0m
2026-04-13 SWA3064 - Apr 13, 18:25 UTCApr 13, 20:10 UTC1h 45m
2026-04-13 SWA139 - Apr 13, 16:15 UTCApr 13, 17:10 UTC55m
2026-04-13 SWA139 - Apr 13, 15:50 UTCApr 13, 17:10 UTC1h 20m
2026-04-13 SWA139 - Apr 13, 14:55 UTCApr 13, 17:01 UTC2h 6m
2026-04-13 SWA139 - Apr 13, 13:15 UTCApr 13, 13:50 UTC35m
2026-04-13 SWA3002 - Apr 13, 10:25 UTCApr 13, 11:55 UTC1h 30m
2026-04-13 SWA458 - Apr 13, 00:20 UTCApr 13, 01:05 UTC45m
2026-04-13 SWA458 - Apr 13, 00:05 UTCApr 13, 01:05 UTC1h 0m
2026-04-12 SWA3377 - Apr 12, 18:45 UTCApr 12, 19:55 UTC1h 10m
2026-04-12 SWA3377 - Apr 12, 17:15 UTCApr 12, 17:35 UTC20m

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 N8948Q page for operator, model, and routing details .

Mode-S AC57AF frequently asked

What is Mode-S code AC57AF?
AC57AF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8948Q.
Where is Mode-S AC57AF registered?
Mode-S code AC57AF 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 AC57AF broadcasting right now?
Yes. Mode-S AC57AF is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC57AF, octal 53053657, decimal 11,294,639.
What flights does AC57AF operate?
Mode-S AC57AF has broadcast 6 distinct callsigns, including SWA139, SWA3064, SWA458, SWA3377, SWA3002.