sensors Mode-S transponder

AAAA4A

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N7868K · BOEING 737-700 · operated by SOUTHWEST AIRLINES CO

Hex
AAAA4A
Octal
52525112
Decimal
11,184,714
Country
US
Tail
N7868K
Type
B737
No current signal · last broadcast 1d ago
Flights observed
7
Distinct callsigns
4
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S AAAA4A.

Country allocation

The ICAO 24-bit address AAAA4A 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 4 distinct

Callsign Airline Flights Last seen
SWA1642 - 3 2026-04-13
SWA3351 - 2 2026-04-13
SWA2360 - 1 2026-04-12
SWA1274 - 1 2026-04-12

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 SWA1642 PHX → PHX Apr 13, 15:57 UTCApr 13, 17:06 UTC1h 9m
2026-04-13 SWA1642 PHX → PHX Apr 13, 15:57 UTCApr 13, 16:58 UTC1h 1m
2026-04-13 SWA1642 - Apr 13, 12:37 UTCApr 13, 14:57 UTC2h 20m
2026-04-13 SWA3351 - Apr 13, 00:20 UTCApr 13, 02:25 UTC2h 5m
2026-04-12 SWA3351 - Apr 12, 23:55 UTCApr 13, 02:25 UTC2h 30m
2026-04-12 SWA2360 - Apr 12, 20:07 UTCApr 12, 21:50 UTC1h 43m
2026-04-12 SWA1274 - Apr 12, 17:35 UTCApr 12, 18:45 UTC1h 10m

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 N7868K page for operator, model, and routing details .

Mode-S AAAA4A frequently asked

What is Mode-S code AAAA4A?
AAAA4A is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N7868K.
Where is Mode-S AAAA4A registered?
Mode-S code AAAA4A 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 AAAA4A 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 AAAA4A, octal 52525112, decimal 11,184,714.
What flights does AAAA4A operate?
Mode-S AAAA4A has broadcast 4 distinct callsigns, including SWA1642, SWA3351, SWA2360, SWA1274.