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sensors Mode-S transponder

A5EC61

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N481AS · BOEING 737-900 · operated by ALASKA AIRLINES INC

Hex
A5EC61
Octal
51366141
Decimal
10,873,953
Country
US
Tail
N481AS
Type
B739
No current signal · last broadcast 1h ago
Flights observed
383
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S A5EC61.

Country allocation

The ICAO 24-bit address A5EC61 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
ASA703 Alaska Airlines 5 2026-05-21
ASA555 - 5 2026-07-05
ASA713 Alaska Airlines 4 2026-04-28
ASA673 - 4 2026-04-17
ASA654 Alaska Airlines 4 2026-06-06
ASA629 - 4 2026-07-09
ASA618 - 4 2026-07-07
ASA500 - 4 2026-07-11
ASA401 - 4 2026-07-06
ASA200 - 4 2026-07-13
ASA1383 Alaska Airlines 4 2026-04-17
ASA1366 - 4 2026-07-09
ASA1311 - 4 2026-06-25
ASA777 Alaska Airlines 3 2026-06-03
ASA706 - 3 2026-06-15
ASA700 Alaska Airlines 3 2026-04-23
ASA633 - 3 2026-07-12
ASA379 Alaska Airlines 3 2026-06-12
ASA1540 Alaska Airlines 3 2026-05-12
ASA1520 - 3 2026-07-06

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 ASA424 - Jul 14, 01:25 UTCJul 14, 04:15 UTC2h 50m
2026-07-13 ASA513 KOA → SEA Jul 13, 18:10 UTCJul 13, 23:30 UTC5h 20m
2026-07-13 ASA513 KOA → SEA Jul 13, 18:07 UTCJul 13, 23:35 UTC5h 28m
2026-07-13 ASA200 SEA → KOA Jul 13, 02:40 UTCJul 13, 08:10 UTC5h 30m
2026-07-13 ASA200 SEA → KOA Jul 13, 02:39 UTCJul 13, 08:08 UTC5h 29m
2026-07-12 ASA652 - Jul 12, 22:45 UTCJul 13, 00:40 UTC1h 55m
2026-07-12 ASA652 SIT → SEA Jul 12, 22:47 UTCJul 13, 00:34 UTC1h 47m
2026-07-12 ASA633 - Jul 12, 19:40 UTCJul 12, 21:25 UTC1h 45m
2026-07-12 ASA633 SEA → SIT Jul 12, 19:38 UTCJul 12, 21:33 UTC1h 55m
2026-07-12 ASA795 SMF → SEA Jul 12, 14:55 UTCJul 12, 16:15 UTC1h 20m
2026-07-12 ASA638 SEA → SMF Jul 12, 03:05 UTCJul 12, 04:40 UTC1h 35m
2026-07-11 ASA500 - Jul 11, 21:35 UTCJul 12, 01:40 UTC4h 5m
2026-07-11 ASA500 SEA → IND Jul 11, 16:35 UTCJul 11, 20:15 UTC3h 40m
2026-07-11 ASA614 - Jul 11, 03:30 UTCJul 11, 05:35 UTC2h 5m
2026-07-11 ASA1300 SEA → LAX Jul 11, 00:00 UTCJul 11, 02:20 UTC2h 20m
2026-07-10 ASA381 DEN → SEA Jul 10, 19:20 UTCJul 10, 21:40 UTC2h 20m
2026-07-10 ASA375 SEA → DEN Jul 10, 15:40 UTCJul 10, 17:55 UTC2h 15m
2026-07-10 ASA1413 SJC → SEA Jul 10, 00:40 UTCJul 10, 02:20 UTC1h 40m
2026-07-09 ASA1366 SEA → SJC Jul 9, 21:55 UTCJul 9, 23:40 UTC1h 45m
2026-07-09 ASA629 LAS → SEA Jul 9, 18:20 UTCJul 9, 20:30 UTC2h 10m
2026-07-09 ASA629 LAS → SEA Jul 9, 18:17 UTCJul 9, 20:16 UTC1h 59m
2026-07-09 ASA1456 SJC → PDX Jul 9, 00:30 UTCJul 9, 02:20 UTC1h 50m
2026-07-09 ASA1456 SJC → PDX Jul 9, 00:26 UTCJul 9, 02:19 UTC1h 53m
2026-07-08 ASA246 - Jul 8, 22:00 UTCJul 8, 23:00 UTC1h 0m
2026-07-08 ASA202 - Jul 8, 02:35 UTCJul 8, 03:30 UTC55m
2026-07-07 ASA618 STL → SEA Jul 7, 20:05 UTCJul 7, 23:55 UTC3h 50m
2026-07-07 ASA618 SEA → STL Jul 7, 15:25 UTCJul 7, 18:50 UTC3h 25m
2026-07-07 ASA758 - Jul 7, 01:35 UTCJul 7, 03:00 UTC1h 25m
2026-07-06 ASA236 PDX → SFO Jul 6, 22:25 UTCJul 7, 00:05 UTC1h 40m
2026-07-06 ASA684 DEN → PDX Jul 6, 18:25 UTCJul 6, 20:45 UTC2h 20m
2026-07-06 ASA684 DEN → PDX Jul 6, 18:28 UTCJul 6, 20:40 UTC2h 12m
2026-07-06 ASA401 PDX → DEN Jul 6, 14:35 UTCJul 6, 16:50 UTC2h 15m
2026-07-06 ASA401 PDX → DEN Jul 6, 14:34 UTCJul 6, 16:36 UTC2h 2m
2026-07-06 ASA1520 FAI → PDX Jul 6, 08:56 UTCJul 6, 12:23 UTC3h 27m
2026-07-06 ASA1520 - Jul 6, 08:30 UTCJul 6, 12:00 UTC3h 30m
2026-07-06 ASA284 - Jul 6, 01:35 UTCJul 6, 04:45 UTC3h 10m
2026-07-05 ASA555 MSP → SEA Jul 5, 20:00 UTCJul 5, 23:25 UTC3h 25m
2026-07-05 ASA555 SEA → MSP Jul 5, 16:05 UTCJul 5, 18:50 UTC2h 45m
2026-07-04 ASA1305 - Jul 4, 20:05 UTCJul 4, 22:05 UTC2h 0m
2026-07-04 ASA1602 SFO → LAX Jul 4, 17:45 UTCJul 4, 18:40 UTC55m
2026-07-04 ASA725 LAS → PDX Jul 4, 14:30 UTCJul 4, 16:15 UTC1h 45m
2026-07-04 ASA259 - Jul 4, 11:45 UTCJul 4, 12:30 UTC45m
2026-07-04 ASA259 - Jul 4, 07:20 UTCJul 4, 07:35 UTC15m
2026-07-03 ASA238 SEA → KOA Jul 3, 23:30 UTCJul 4, 05:00 UTC5h 30m
2026-07-03 ASA785 LAS → SEA Jul 3, 18:45 UTCJul 3, 21:05 UTC2h 20m
2026-07-03 ASA612 SEA → LAS Jul 3, 15:16 UTCJul 3, 17:01 UTC1h 45m
2026-07-03 ASA612 SEA → LAS Jul 3, 15:10 UTCJul 3, 17:05 UTC1h 55m
2026-07-03 ASA550 DFW → SEA Jul 3, 02:20 UTCJul 3, 05:55 UTC3h 35m
2026-07-02 ASA380 SEA → MSP Jul 2, 21:55 UTCJul 3, 00:00 UTC2h 5m
2026-07-02 ASA380 SEA → MSP Jul 2, 21:40 UTCJul 3, 00:10 UTC2h 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 N481AS page for operator, model, and routing details .

Mode-S A5EC61 frequently asked

What is Mode-S code A5EC61?
A5EC61 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N481AS.
Where is Mode-S A5EC61 registered?
Mode-S code A5EC61 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 A5EC61 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A5EC61, octal 51366141, decimal 10,873,953.
What flights does A5EC61 operate?
Mode-S A5EC61 has broadcast 20 distinct callsigns, including ASA703, ASA555, ASA713, ASA673, ASA654.