sensors Mode-S transponder

A4C6B3

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N407AS · BOEING 737-900 · operated by ALASKA AIRLINES INC

Hex
A4C6B3
Octal
51143263
Decimal
10,798,771
Country
US
Tail
N407AS
Type
B739
No current signal · last broadcast 11h ago
Flights observed
189
Distinct callsigns
20
Country
US
Last broadcast
11h ago

Last known position

Most recent position reported by Mode-S A4C6B3.

Country allocation

The ICAO 24-bit address A4C6B3 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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 ASA671 SEA → SFO May 29, 14:45 UTCMay 29, 17:50 UTC3h 5m
2026-05-29 ASA1463 PVR → SEA May 29, 03:00 UTCMay 29, 04:25 UTC1h 25m
2026-05-29 ASA1385 SJC → SEA May 29, 00:00 UTCMay 29, 01:40 UTC1h 40m
2026-05-29 ASA1385 SJC → SEA May 29, 00:02 UTCMay 29, 01:32 UTC1h 30m
2026-05-28 ASA1365 PVR → SFO May 28, 20:05 UTCMay 28, 21:30 UTC1h 25m
2026-05-28 ASA1540 SEA → ANC May 28, 17:30 UTCMay 28, 18:55 UTC1h 25m
2026-05-28 ASA705 LAX → SEA May 28, 14:20 UTCMay 28, 15:55 UTC1h 35m
2026-05-28 ASA706 SFO → LAS May 28, 05:10 UTCMay 28, 06:45 UTC1h 35m
2026-05-27 ASA508 CVG → SEA May 27, 23:25 UTCMay 28, 03:40 UTC4h 15m
2026-05-27 ASA508 CVG → SEA May 27, 23:21 UTCMay 28, 03:22 UTC4h 1m
2026-05-27 ASA508 CVG → SEA May 27, 18:00 UTCMay 27, 22:10 UTC4h 10m
2026-05-27 ASA479 JFK → SFO May 27, 14:25 UTCMay 27, 16:30 UTC2h 5m
2026-05-27 ASA479 JFK → SFO May 27, 14:22 UTCMay 27, 16:19 UTC1h 57m
2026-05-27 ASA56 LAX → PDX May 27, 07:40 UTCMay 27, 12:00 UTC4h 20m
2026-05-27 ASA53 EWR → PDX May 27, 02:09 UTCMay 27, 05:40 UTC3h 30m
2026-05-26 ASA658 SEA → PHX May 26, 21:20 UTCMay 26, 23:35 UTC2h 15m
2026-05-25 ASA230 SMF → SEA May 25, 20:19 UTCMay 25, 23:14 UTC2h 55m
2026-05-25 ASA79 SJC → PVR May 25, 15:55 UTCMay 25, 19:10 UTC3h 15m
2026-05-25 ASA267 SEA → AUS May 25, 06:05 UTCMay 25, 06:55 UTC50m
2026-05-24 ASA626 SFO → SEA May 24, 23:00 UTCMay 24, 23:20 UTC20m
2026-05-24 ASA626 SFO → SEA May 24, 18:10 UTCMay 24, 18:55 UTC45m
2026-05-24 ASA548 MZT → SFO May 24, 11:15 UTCMay 24, 15:50 UTC4h 35m
2026-05-23 ASA216 SEA → CLE May 23, 19:15 UTCMay 23, 23:10 UTC3h 55m
2026-05-23 ASA515 BOS → PDX May 23, 13:10 UTCMay 23, 17:25 UTC4h 15m
2026-05-23 ASA328 SEA → ORD May 23, 07:20 UTCMay 23, 10:45 UTC3h 25m
2026-05-23 ASA652 RNO → SEA May 23, 03:20 UTCMay 23, 05:40 UTC2h 20m
2026-05-23 ASA652 RNO → SEA May 23, 03:16 UTCMay 23, 05:38 UTC2h 22m
2026-05-23 ASA266 SJC → PDX May 23, 01:00 UTCMay 23, 01:50 UTC50m
2026-05-22 ASA266 SJC → PDX May 22, 20:50 UTCMay 22, 20:55 UTC5m
2026-05-22 ASA266 SJC → PDX May 22, 20:46 UTCMay 23, 01:48 UTC5h 2m
2026-05-22 ASA54 ANC → LAS May 22, 19:10 UTCMay 22, 19:25 UTC15m
2026-05-22 ASA54 ANC → LAS May 22, 14:30 UTCMay 22, 15:00 UTC30m
2026-05-22 ASA1350 SEA → SFO May 22, 04:20 UTCMay 22, 05:45 UTC1h 25m
2026-05-21 ASA1787 PHL → PDX May 21, 21:15 UTCMay 22, 02:40 UTC5h 25m
2026-05-21 ASA1776 PDX → PHL May 21, 14:55 UTCMay 21, 19:25 UTC4h 30m
2026-05-20 ASA1377 PVR → PDX May 20, 23:40 UTCMay 21, 04:00 UTC4h 20m
2026-05-20 ASA522 SEA → BNA May 20, 17:55 UTCMay 20, 21:50 UTC3h 55m
2026-05-20 ASA387 MSP → SEA May 20, 12:41 UTCMay 20, 15:33 UTC2h 52m
2026-05-20 ASA387 MSP → SEA May 20, 12:25 UTCMay 20, 15:40 UTC3h 15m
2026-05-20 ASA386 SEA → MSP May 20, 02:10 UTCMay 20, 04:55 UTC2h 46m
2026-05-20 ASA386 SEA → MSP May 20, 02:05 UTCMay 20, 04:49 UTC2h 44m
2026-05-19 ASA458 PDX → MCO May 19, 21:45 UTCMay 20, 00:25 UTC2h 40m
2026-05-19 ASA716 SFO → SAN May 19, 17:50 UTCMay 19, 20:00 UTC2h 10m
2026-05-19 ASA1472 EWR → SEA May 19, 15:15 UTCMay 19, 16:10 UTC55m
2026-05-19 ASA550 EWR → SFO May 19, 04:45 UTCMay 19, 05:40 UTC55m
2026-05-18 ASA494 SEA → SAT May 18, 23:10 UTCMay 19, 03:05 UTC3h 55m
2026-05-18 ASA494 SEA → SAT May 18, 18:05 UTCMay 18, 21:40 UTC3h 34m
2026-05-18 ASA1413 GDL → LAX May 18, 14:25 UTCMay 18, 16:40 UTC2h 15m
2026-05-18 ASA1389 SJD → SEA May 18, 04:40 UTCMay 18, 06:25 UTC1h 45m
2026-05-17 ASA290 PDX → EWR May 17, 21:30 UTCMay 18, 02:50 UTC5h 20m

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 N407AS page for operator, model, and routing details .

Mode-S A4C6B3 frequently asked

What is Mode-S code A4C6B3?
A4C6B3 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N407AS.
Where is Mode-S A4C6B3 registered?
Mode-S code A4C6B3 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 A4C6B3 broadcasting right now?
No active broadcast right now. Last signal was 11h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4C6B3, octal 51143263, decimal 10,798,771.
What flights does A4C6B3 operate?
Mode-S A4C6B3 has broadcast 20 distinct callsigns, including ASA397, ASA396, ASA387, ASA386, ASA294.