sensors Mode-S transponder

AB349C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N821AK · BOEING 737 MAX 8 · operated by ALASKA AIRLINES INC

Hex
AB349C
Octal
52632234
Decimal
11,220,124
Country
US
Tail
N821AK
Type
B38M
Broadcasting now · callsign ASA410 · 4,225 ft
Flights observed
8
Distinct callsigns
5
Country
US
Last broadcast
16h ago

Current position

AB349C is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AB349C 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 5 distinct

Callsign Airline Flights Last seen
ASA10 - 3 2026-04-13
ASA253 - 2 2026-04-13
ASA560 - 1 2026-04-12
ASA3 Alaska Airlines 1 2026-04-13
ASA1433 Alaska Airlines 1 2026-04-14

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-14 ASA1433 SJD → SFO Apr 14, 05:15 UTCApr 14, 06:45 UTC1h 30m
2026-04-13 ASA3 DCA → SEA Apr 13, 21:15 UTCApr 13, 23:40 UTC2h 25m
2026-04-13 ASA10 - Apr 13, 16:40 UTCApr 13, 19:40 UTC3h 0m
2026-04-13 ASA10 - Apr 13, 15:50 UTCApr 13, 19:40 UTC3h 50m
2026-04-13 ASA10 - Apr 13, 15:21 UTCApr 13, 19:47 UTC4h 26m
2026-04-13 ASA253 - Apr 13, 04:20 UTCApr 13, 05:10 UTC50m
2026-04-13 ASA253 - Apr 13, 00:00 UTCApr 13, 00:10 UTC10m
2026-04-12 ASA560 - Apr 12, 17:15 UTCApr 12, 17:25 UTC10m

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 N821AK page for operator, model, and routing details .

Mode-S AB349C frequently asked

What is Mode-S code AB349C?
AB349C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N821AK.
Where is Mode-S AB349C registered?
Mode-S code AB349C 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 AB349C broadcasting right now?
Yes. Mode-S AB349C is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AB349C, octal 52632234, decimal 11,220,124.
What flights does AB349C operate?
Mode-S AB349C has broadcast 5 distinct callsigns, including ASA10, ASA253, ASA560, ASA3, ASA1433.