sensors Mode-S transponder

AC33A3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N8856S · BOEING 737 MAX 8 · operated by SOUTHWEST AIRLINES CO

Hex
AC33A3
Octal
53031643
Decimal
11,285,411
Country
US
Tail
N8856S
Type
B38M
No current signal · last broadcast 1d ago
Flights observed
15
Distinct callsigns
8
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AC33A3.

Country allocation

The ICAO 24-bit address AC33A3 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
SWA4454 - 3 2026-04-13
SWA2946 - 3 2026-04-13
SWA1983 Southwest Airlines 3 2026-04-13
SWA1035 - 2 2026-04-13
SWA3396 - 1 2026-04-13
SWA3155 - 1 2026-04-12
SWA1968 - 1 2026-04-13
SWA1431 - 1 2026-04-12

Recent flights last 15

DateFlightRouteTakeoffLandingDuration
2026-04-13 SWA1968 - Apr 13, 21:47 UTCApr 14, 00:00 UTC2h 13m
2026-04-13 SWA2946 - Apr 13, 19:50 UTCApr 13, 20:35 UTC45m
2026-04-13 SWA2946 - Apr 13, 17:56 UTCApr 13, 20:34 UTC2h 38m
2026-04-13 SWA2946 - Apr 13, 18:05 UTCApr 13, 20:30 UTC2h 25m
2026-04-13 SWA1983 SJC → SLC Apr 13, 16:15 UTCApr 13, 17:05 UTC50m
2026-04-13 SWA1983 SJC → SLC Apr 13, 15:50 UTCApr 13, 17:05 UTC1h 15m
2026-04-13 SWA1983 SJC → SLC Apr 13, 14:50 UTCApr 13, 16:15 UTC1h 25m
2026-04-13 SWA4454 - Apr 13, 12:20 UTCApr 13, 13:30 UTC1h 10m
2026-04-13 SWA4454 - Apr 13, 11:55 UTCApr 13, 13:30 UTC1h 35m
2026-04-13 SWA4454 - Apr 13, 11:30 UTCApr 13, 12:15 UTC45m
2026-04-13 SWA3396 - Apr 13, 03:01 UTCApr 13, 03:54 UTC53m
2026-04-13 SWA1035 - Apr 13, 00:20 UTCApr 13, 01:35 UTC1h 15m
2026-04-12 SWA1035 - Apr 12, 23:55 UTCApr 13, 01:35 UTC1h 40m
2026-04-12 SWA1431 - Apr 12, 19:56 UTCApr 12, 21:54 UTC1h 58m
2026-04-12 SWA3155 - Apr 12, 18:25 UTCApr 12, 19:10 UTC45m

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 N8856S page for operator, model, and routing details .

Mode-S AC33A3 frequently asked

What is Mode-S code AC33A3?
AC33A3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N8856S.
Where is Mode-S AC33A3 registered?
Mode-S code AC33A3 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 AC33A3 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AC33A3, octal 53031643, decimal 11,285,411.
What flights does AC33A3 operate?
Mode-S AC33A3 has broadcast 8 distinct callsigns, including SWA4454, SWA2946, SWA1983, SWA1035, SWA3396.