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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 Jul 26, 21:15 UTC
Flights observed
436
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:15 UTC

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
ASA70 Alaska Airlines 3 2026-07-24
ASA633 - 3 2026-07-12
ASA536 Alaska Airlines 3 2026-07-21
ASA379 Alaska Airlines 3 2026-06-12

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ASA733 LAS → SEA Jul 26, 19:40 UTCJul 26, 21:10 UTC1h 30m
2026-07-26 ASA365 SFO → LAS Jul 26, 14:20 UTCJul 26, 17:55 UTC3h 35m
2026-07-26 ASA365 SFO → LAS Jul 26, 14:17 UTCJul 26, 17:36 UTC3h 19m
2026-07-26 ASA424 SEA → BOS Jul 26, 02:30 UTCJul 26, 05:45 UTC3h 15m
2026-07-25 ASA405 SEA → OKC Jul 25, 20:40 UTCJul 26, 00:05 UTC3h 25m
2026-07-25 ASA405 SEA → OKC Jul 25, 16:10 UTCJul 25, 19:10 UTC3h 0m
2026-07-25 ASA1518 SAN → ORD Jul 25, 02:10 UTCJul 25, 05:10 UTC3h 0m
2026-07-24 ASA1438 SAN → SJD Jul 24, 21:55 UTCJul 24, 22:15 UTC20m
2026-07-24 ASA1438 SAN → SJD Jul 24, 21:54 UTCJul 24, 22:42 UTC48m
2026-07-24 ASA1437 SFO → LAX Jul 24, 19:45 UTCJul 24, 20:30 UTC45m
2026-07-24 ASA73 JNU → ANC Jul 24, 15:50 UTCJul 24, 17:10 UTC1h 20m
2026-07-24 ASA73 JNU → ANC Jul 24, 14:15 UTCJul 24, 14:30 UTC15m
2026-07-24 ASA70 ANC → JNU Jul 24, 06:20 UTCJul 24, 06:45 UTC25m
2026-07-24 ASA70 ANC → JNU Jul 24, 04:10 UTCJul 24, 05:15 UTC1h 5m
2026-07-24 ASA70 ANC → JNU Jul 24, 04:06 UTCJul 24, 05:20 UTC1h 14m
2026-07-23 ASA9665 ANC → SCC Jul 23, 22:15 UTCJul 24, 02:10 UTC3h 55m
2026-07-23 ASA9660 - Jul 23, 19:35 UTCJul 23, 20:25 UTC50m
2026-07-23 ASA9660 SCC → ANC Jul 23, 19:02 UTCJul 23, 20:31 UTC1h 29m
2026-07-23 ASA9661 ANC → SCC Jul 23, 16:42 UTCJul 23, 18:01 UTC1h 19m
2026-07-23 ASA9661 - Jul 23, 16:40 UTCJul 23, 17:35 UTC55m
2026-07-23 ASA771 ORD → SFO Jul 23, 05:50 UTCJul 23, 09:05 UTC3h 15m
2026-07-22 ASA572 RDU → SEA Jul 22, 21:45 UTCJul 23, 02:55 UTC5h 10m
2026-07-22 ASA572 RDU → SEA Jul 22, 15:35 UTCJul 22, 20:10 UTC4h 35m
2026-07-22 ASA481 SEA → BZE Jul 22, 03:10 UTCJul 22, 04:45 UTC1h 35m
2026-07-21 ASA319 BOS → SFO Jul 21, 23:55 UTCJul 22, 01:40 UTC1h 45m
2026-07-21 ASA319 BOS → SFO Jul 21, 23:52 UTCJul 22, 01:39 UTC1h 47m
2026-07-21 ASA338 BOS → SEA Jul 21, 16:40 UTCJul 21, 22:25 UTC5h 45m
2026-07-21 ASA536 SEA → BOS Jul 21, 07:15 UTCJul 21, 11:50 UTC4h 35m
2026-07-21 ASA647 LAS → PDX Jul 21, 02:05 UTCJul 21, 05:50 UTC3h 45m
2026-07-20 ASA647 LAS → PDX Jul 20, 20:20 UTCJul 20, 23:30 UTC3h 10m
2026-07-20 ASA1327 SFO → SEA Jul 20, 17:05 UTCJul 20, 18:30 UTC1h 25m
2026-07-20 ASA1327 SFO → SEA Jul 20, 17:05 UTCJul 20, 18:26 UTC1h 21m
2026-07-19 ASA421 SEA → SFO Jul 19, 18:40 UTCJul 20, 02:20 UTC7h 40m
2026-07-19 ASA1426 LAX → ZIH Jul 19, 15:15 UTCJul 19, 16:50 UTC1h 35m
2026-07-19 ASA539 SEA → SJC Jul 19, 01:00 UTCJul 19, 02:45 UTC1h 45m
2026-07-18 ASA582 - Jul 18, 21:25 UTCJul 18, 23:25 UTC2h 0m
2026-07-18 ASA692 - Jul 18, 17:50 UTCJul 18, 20:05 UTC2h 15m
2026-07-18 ASA519 - Jul 18, 12:25 UTCJul 18, 16:05 UTC3h 40m
2026-07-18 ASA520 SEA → SAT Jul 18, 06:35 UTCJul 18, 10:10 UTC3h 35m
2026-07-18 ASA1368 - Jul 18, 03:05 UTCJul 18, 05:05 UTC2h 0m
2026-07-18 ASA1523 HAF → LAX Jul 18, 00:45 UTCJul 18, 01:39 UTC55m
2026-07-17 ASA680 SEA → SFO Jul 17, 21:30 UTCJul 17, 23:25 UTC1h 55m
2026-07-17 ASA680 SEA → SFO Jul 17, 21:28 UTCJul 17, 23:16 UTC1h 48m
2026-07-16 ASA519 - Jul 16, 12:30 UTCJul 16, 16:30 UTC4h 0m
2026-07-16 ASA520 - Jul 16, 06:20 UTCJul 16, 10:29 UTC4h 10m
2026-07-16 ASA1375 LAX → SEA Jul 16, 01:37 UTCJul 16, 03:23 UTC1h 46m
2026-07-16 ASA1375 - Jul 16, 01:20 UTCJul 16, 03:25 UTC2h 5m
2026-07-15 ASA502 - Jul 15, 19:55 UTCJul 15, 22:15 UTC2h 20m
2026-07-15 ASA753 - Jul 15, 16:05 UTCJul 15, 18:10 UTC2h 5m
2026-07-15 ASA369 PDX → SAN Jul 15, 01:10 UTCJul 15, 03:40 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 Jul 26, 21:15 UTC.
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.