sensors Mode-S transponder

AC5A73

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8951S · operated by SOUTHWEST AIRLINES CO

Hex
AC5A73
Octal
53055163
Decimal
11,295,347
Country
US
Tail
N8951S
Type
B38M
Broadcasting now · callsign SWA339 · 12,700 ft
Flights observed
14
Distinct callsigns
7
Country
US
Last broadcast
12h ago

Current position

AC5A73 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AC5A73 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 7 distinct

Callsign Airline Flights Last seen
SWA4088 Southwest Airlines 4 2026-04-13
SWA687 - 2 2026-04-13
SWA3768 - 2 2026-04-13
SWA3067 Southwest Airlines 2 2026-04-13
SWA1102 - 2 2026-04-13
SWA1529 - 1 2026-04-13
SWA1020 - 1 2026-04-14

Recent flights last 14

DateFlightRouteTakeoffLandingDuration
2026-04-14 SWA1020 - Apr 14, 10:50 UTCApr 14, 11:05 UTC15m
2026-04-13 SWA3768 - Apr 13, 21:21 UTCApr 13, 22:52 UTC1h 31m
2026-04-13 SWA3768 - Apr 13, 21:21 UTCApr 13, 22:52 UTC1h 31m
2026-04-13 SWA687 - Apr 13, 19:50 UTCApr 13, 20:25 UTC35m
2026-04-13 SWA687 - Apr 13, 16:52 UTCApr 13, 20:24 UTC3h 32m
2026-04-13 SWA1102 - Apr 13, 13:30 UTCApr 13, 15:45 UTC2h 15m
2026-04-13 SWA1102 - Apr 13, 12:20 UTCApr 13, 12:25 UTC5m
2026-04-13 SWA3067 AMA → AUS Apr 13, 11:55 UTCApr 13, 12:25 UTC30m
2026-04-13 SWA3067 AMA → AUS Apr 13, 10:10 UTCApr 13, 12:15 UTC2h 5m
2026-04-13 SWA4088 BUR → SJC Apr 13, 04:20 UTCApr 13, 06:15 UTC1h 55m
2026-04-13 SWA4088 BUR → SJC Apr 13, 03:55 UTCApr 13, 06:15 UTC2h 20m
2026-04-13 SWA4088 BUR → SJC Apr 13, 03:15 UTCApr 13, 05:58 UTC2h 43m
2026-04-13 SWA4088 BUR → SJC Apr 13, 03:32 UTCApr 13, 06:11 UTC2h 39m
2026-04-13 SWA1529 - Apr 13, 00:20 UTCApr 13, 02:25 UTC2h 5m

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 N8951S page for operator, model, and routing details .

Mode-S AC5A73 frequently asked

What is Mode-S code AC5A73?
AC5A73 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8951S.
Where is Mode-S AC5A73 registered?
Mode-S code AC5A73 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 AC5A73 broadcasting right now?
Yes. Mode-S AC5A73 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC5A73, octal 53055163, decimal 11,295,347.
What flights does AC5A73 operate?
Mode-S AC5A73 has broadcast 7 distinct callsigns, including SWA4088, SWA687, SWA3768, SWA3067, SWA1102.