Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A9B273

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N724AL · operated by ALASKA AIRLINES INC

Hex
A9B273
Octal
52331163
Decimal
11,121,267
Country
US
Tail
N724AL
Type
B39M
Broadcasting now · callsign ASA375 · 10,175 ft
Flights observed
429
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:30 UTC

Current position

A9B273 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A9B273 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 20 distinct

Callsign Airline Flights Last seen
ASA379 - 6 2026-06-27
ASA657 Alaska Airlines 5 2026-07-20
ASA378 - 5 2026-06-27
ASA228 Alaska Airlines 5 2026-06-03
ASA200 Alaska Airlines 5 2026-06-12
ASA752 - 4 2026-06-15
ASA678 Alaska Airlines 4 2026-07-18
ASA670 Alaska Airlines 4 2026-05-12
ASA647 - 4 2026-07-13
ASA639 Alaska Airlines 4 2026-04-15
ASA565 Alaska Airlines 4 2026-06-08
ASA550 - 4 2026-06-27
ASA519 - 4 2026-06-28
ASA465 Alaska Airlines 4 2026-06-05
ASA419 Alaska Airlines 4 2026-04-17
ASA331 Alaska Airlines 4 2026-06-01
ASA300 Alaska Airlines 4 2026-04-16
ASA94 Alaska Airlines 3 2026-05-11
ASA799 - 3 2026-04-14
ASA745 Alaska Airlines 3 2026-05-24

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ASA1346 SAN → ZIH Jul 26, 18:50 UTCJul 26, 21:15 UTC2h 25m
2026-07-26 ASA645 PHX → SEA Jul 26, 14:30 UTCJul 26, 17:05 UTC2h 35m
2026-07-26 ASA644 SEA → PHX Jul 26, 04:10 UTCJul 26, 06:35 UTC2h 26m
2026-07-25 ASA503 LAX → SEA Jul 25, 22:05 UTCJul 26, 01:50 UTC3h 45m
2026-07-25 ASA422 SEA → SFO Jul 25, 16:50 UTCJul 25, 20:20 UTC3h 30m
2026-07-25 ASA620 SEA → DEN Jul 25, 13:25 UTCJul 25, 14:55 UTC1h 30m
2026-07-25 ASA590 SFO → ORD Jul 25, 05:55 UTCJul 25, 07:45 UTC1h 50m
2026-07-25 ASA1413 GDL → LAX Jul 25, 01:10 UTCJul 25, 02:40 UTC1h 30m
2026-07-24 ASA1366 SJD → LAX Jul 24, 21:55 UTCJul 24, 23:45 UTC1h 50m
2026-07-24 ASA629 LAS → SEA Jul 24, 17:58 UTCJul 24, 20:00 UTC2h 2m
2026-07-24 ASA629 LAS → SEA Jul 24, 18:10 UTCJul 24, 20:15 UTC2h 5m
2026-07-24 ASA777 SEA → OAK Jul 24, 14:05 UTCJul 24, 16:15 UTC2h 10m
2026-07-24 ASA366 MKE → SEA Jul 24, 03:20 UTCJul 24, 05:15 UTC1h 55m
2026-07-24 ASA366 MKE → SEA Jul 24, 03:18 UTCJul 24, 05:14 UTC1h 56m
2026-07-23 ASA1456 SJC → PDX Jul 23, 23:50 UTCJul 24, 01:55 UTC2h 5m
2026-07-23 ASA1456 SJC → PDX Jul 23, 23:47 UTCJul 24, 01:50 UTC2h 3m
2026-07-23 ASA596 LAS → PDX Jul 23, 20:15 UTCJul 23, 21:55 UTC1h 40m
2026-07-23 ASA653 SFO → ZIH Jul 23, 17:30 UTCJul 23, 18:45 UTC1h 15m
2026-07-23 ASA653 SFO → ZIH Jul 23, 17:25 UTCJul 23, 19:01 UTC1h 36m
2026-07-23 ASA554 PDX → ORD Jul 23, 12:10 UTCJul 23, 15:35 UTC3h 25m
2026-07-23 ASA553 IAD → SFO Jul 23, 01:35 UTCJul 23, 04:45 UTC3h 10m
2026-07-22 ASA456 SFO → ORD Jul 22, 22:10 UTCJul 23, 00:05 UTC1h 55m
2026-07-22 ASA209 LAX → SFO Jul 22, 18:50 UTCJul 22, 20:45 UTC1h 55m
2026-07-22 ASA459 BOS → SEA Jul 22, 11:33 UTCJul 22, 16:51 UTC5h 18m
2026-07-22 ASA459 BOS → SEA Jul 22, 11:30 UTCJul 22, 17:05 UTC5h 35m
2026-07-22 ASA255 CLE → SEA Jul 22, 04:15 UTCJul 22, 05:25 UTC1h 10m
2026-07-21 ASA389 SAN → SJC Jul 21, 21:15 UTCJul 22, 03:00 UTC5h 45m
2026-07-21 ASA358 PDX → BOS Jul 21, 14:15 UTCJul 21, 19:25 UTC5h 10m
2026-07-21 ASA1609 ANC → PDX Jul 21, 00:40 UTCJul 21, 04:05 UTC3h 25m
2026-07-20 ASA657 JFK → SFO Jul 20, 19:55 UTCJul 20, 23:10 UTC3h 15m
2026-07-20 ASA657 JFK → SFO Jul 20, 19:46 UTCJul 20, 22:59 UTC3h 13m
2026-07-20 ASA215 AUS → SEA Jul 20, 13:45 UTCJul 20, 17:25 UTC3h 40m
2026-07-20 ASA1370 PVR → SFO Jul 20, 01:15 UTCJul 20, 04:40 UTC3h 25m
2026-07-19 ASA267 ANC → PDX Jul 19, 20:05 UTCJul 19, 23:20 UTC3h 15m
2026-07-19 ASA1541 MSP → ANC Jul 19, 13:05 UTCJul 19, 18:20 UTC5h 15m
2026-07-19 ASA1540 - Jul 19, 06:00 UTCJul 19, 10:55 UTC4h 55m
2026-07-19 ASA271 PDX → ANC Jul 19, 01:00 UTCJul 19, 04:15 UTC3h 15m
2026-07-18 ASA1315 LAX → PDX Jul 18, 21:50 UTCJul 18, 23:35 UTC1h 45m
2026-07-18 ASA695 SJC → PDX Jul 18, 18:10 UTCJul 18, 20:25 UTC2h 15m
2026-07-18 ASA679 SJC → PDX Jul 18, 15:05 UTCJul 18, 16:30 UTC1h 25m
2026-07-18 ASA678 SJC → SEA Jul 18, 05:10 UTCJul 18, 06:40 UTC1h 30m
2026-07-18 ASA678 SJC → SEA Jul 18, 05:08 UTCJul 18, 06:42 UTC1h 34m
2026-07-17 ASA290 EWR → PDX Jul 17, 21:20 UTCJul 18, 02:40 UTC5h 20m
2026-07-17 ASA294 - Jul 17, 15:00 UTCJul 17, 19:40 UTC4h 40m
2026-07-17 ASA207 LAX → PDX Jul 17, 04:44 UTCJul 17, 06:29 UTC1h 45m
2026-07-17 ASA763 - Jul 17, 02:34 UTCJul 17, 03:10 UTC35m
2026-07-16 ASA763 - Jul 16, 22:15 UTCJul 16, 22:35 UTC20m
2026-07-16 ASA1416 - Jul 16, 20:09 UTCJul 16, 20:29 UTC20m
2026-07-16 ASA1416 - Jul 16, 15:25 UTCJul 16, 16:05 UTC40m
2026-07-16 ASA678 PDX → SJC Jul 16, 04:45 UTCJul 16, 06:15 UTC1h 30m

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 N724AL page for operator, model, and routing details .

Mode-S A9B273 frequently asked

What is Mode-S code A9B273?
A9B273 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N724AL.
Where is Mode-S A9B273 registered?
Mode-S code A9B273 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 A9B273 broadcasting right now?
Yes. Mode-S A9B273 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A9B273, octal 52331163, decimal 11,121,267.
What flights does A9B273 operate?
Mode-S A9B273 has broadcast 20 distinct callsigns, including ASA379, ASA657, ASA378, ASA228, ASA200.