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sensors Mode-S transponder

A2C087

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N277AK · BOEING 737-900 · operated by ALASKA AIRLINES INC

Hex
A2C087
Octal
50540207
Decimal
10,666,119
Country
US
Tail
N277AK
Type
B739
Broadcasting now · callsign ASA642 · 12,350 ft
Flights observed
326
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:45 UTC

Current position

A2C087 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A2C087 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
ASA412 - 8 2026-06-27
ASA365 - 5 2026-07-11
ASA25 Alaska Airlines 5 2026-05-15
ASA409 - 4 2026-07-18
ASA352 Alaska Airlines 4 2026-05-27
ASA317 - 4 2026-07-02
ASA211 Alaska Airlines 4 2026-04-25
ASA1496 Alaska Airlines 4 2026-05-24
ASA9450 Alaska Airlines 3 2026-06-26
ASA726 Alaska Airlines 3 2026-05-23
ASA701 Alaska Airlines 3 2026-05-11
ASA602 - 3 2026-07-01
ASA500 Alaska Airlines 3 2026-04-13
ASA415 - 3 2026-07-01
ASA414 Alaska Airlines 3 2026-07-01
ASA410 Alaska Airlines 3 2026-04-17
ASA375 - 3 2026-07-17
ASA348 - 3 2026-07-15
ASA271 Alaska Airlines 3 2026-07-22
ASA18 Alaska Airlines 3 2026-05-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ASA497 ATL → SEA Jul 26, 21:10 UTCJul 26, 21:45 UTC35m
2026-07-26 ASA720 SEA → OAK Jul 26, 17:30 UTCJul 26, 19:30 UTC2h 0m
2026-07-26 ASA488 SEA → IND Jul 26, 13:45 UTCJul 26, 16:00 UTC2h 15m
2026-07-26 ASA611 LAX → SEA Jul 26, 02:25 UTCJul 26, 04:50 UTC2h 25m
2026-07-25 ASA515 BOS → PDX Jul 25, 22:15 UTCJul 26, 01:10 UTC2h 55m
2026-07-25 ASA514 PDX → BOS Jul 25, 18:05 UTCJul 25, 20:35 UTC2h 30m
2026-07-25 ASA1349 ZIH → SFO Jul 25, 14:10 UTCJul 25, 16:25 UTC2h 15m
2026-07-24 ASA1519 ANC → FAI Jul 24, 22:55 UTCJul 25, 02:15 UTC3h 20m
2026-07-24 ASA1519 ANC → FAI Jul 24, 22:53 UTCJul 25, 02:13 UTC3h 20m
2026-07-24 ASA1525 MCO → SEA Jul 24, 18:45 UTCJul 24, 21:35 UTC2h 50m
2026-07-24 ASA349 - Jul 24, 15:05 UTCJul 24, 16:50 UTC1h 45m
2026-07-24 ASA1636 ANC → LAS Jul 24, 08:15 UTCJul 24, 13:00 UTC4h 45m
2026-07-24 ASA661 PHX → PAE Jul 24, 02:50 UTCJul 24, 06:10 UTC3h 20m
2026-07-24 ASA661 PHX → PAE Jul 24, 02:49 UTCJul 24, 06:09 UTC3h 20m
2026-07-23 ASA425 SFO → BOS Jul 23, 22:25 UTCJul 24, 00:38 UTC2h 13m
2026-07-23 ASA425 SFO → BOS Jul 23, 22:20 UTCJul 23, 23:45 UTC1h 25m
2026-07-23 ASA747 - Jul 23, 17:45 UTCJul 23, 20:15 UTC2h 30m
2026-07-23 ASA1572 - Jul 23, 14:10 UTCJul 23, 16:20 UTC2h 10m
2026-07-23 ASA531 LAX → PDX Jul 23, 01:10 UTCJul 23, 03:05 UTC1h 55m
2026-07-22 ASA267 - Jul 22, 20:10 UTCJul 22, 23:25 UTC3h 15m
2026-07-22 ASA1541 MSP → ANC Jul 22, 12:55 UTCJul 22, 18:40 UTC5h 45m
2026-07-22 ASA271 SFO → PDX Jul 22, 01:20 UTCJul 22, 04:35 UTC3h 15m
2026-07-21 ASA267 ANC → PDX Jul 21, 20:00 UTCJul 21, 23:15 UTC3h 15m
2026-07-21 ASA1541 MSP → ANC Jul 21, 13:05 UTCJul 21, 18:15 UTC5h 10m
2026-07-21 ASA1540 SEA → ANC Jul 21, 06:05 UTCJul 21, 10:50 UTC4h 45m
2026-07-21 ASA1540 SEA → ANC Jul 21, 06:02 UTCJul 21, 10:41 UTC4h 39m
2026-07-21 ASA271 SFO → PDX Jul 21, 01:00 UTCJul 21, 04:10 UTC3h 10m
2026-07-21 ASA271 SFO → PDX Jul 21, 01:00 UTCJul 21, 04:07 UTC3h 7m
2026-07-20 ASA325 - Jul 20, 19:50 UTCJul 20, 23:35 UTC3h 45m
2026-07-20 ASA324 PDX → ORD Jul 20, 14:15 UTCJul 20, 18:00 UTC3h 45m
2026-07-19 ASA1787 PHL → PDX Jul 19, 22:40 UTCJul 20, 04:00 UTC5h 20m
2026-07-19 ASA1787 PHL → PDX Jul 19, 22:20 UTCJul 19, 22:30 UTC10m
2026-07-19 ASA442 SEA → PHL Jul 19, 15:55 UTCJul 19, 20:20 UTC4h 25m
2026-07-19 ASA279 GEG → SEA Jul 19, 13:25 UTCJul 19, 14:15 UTC50m
2026-07-19 ASA1614 LAX → GEG Jul 19, 03:30 UTCJul 19, 05:20 UTC1h 50m
2026-07-18 ASA1300 SEA → LAX Jul 18, 23:40 UTCJul 19, 02:00 UTC2h 20m
2026-07-18 ASA596 - Jul 18, 20:40 UTCJul 18, 22:05 UTC1h 25m
2026-07-18 ASA653 - Jul 18, 17:50 UTCJul 18, 19:10 UTC1h 20m
2026-07-18 ASA409 IAD → SEA Jul 18, 11:00 UTCJul 18, 15:28 UTC4h 28m
2026-07-18 ASA409 IAD → SEA Jul 18, 10:45 UTCJul 18, 15:45 UTC5h 0m
2026-07-17 ASA406 SEA → IAD Jul 17, 23:30 UTCJul 18, 04:05 UTC4h 36m
2026-07-17 ASA381 DTW → SEA Jul 17, 19:25 UTCJul 17, 21:39 UTC2h 15m
2026-07-17 ASA375 - Jul 17, 15:35 UTCJul 17, 17:44 UTC2h 10m
2026-07-17 ASA375 SEA → DEN Jul 17, 15:32 UTCJul 17, 17:41 UTC2h 9m
2026-07-16 ASA1508 - Jul 16, 00:10 UTCJul 16, 03:35 UTC3h 25m
2026-07-15 ASA1507 SEA → FAI Jul 15, 19:35 UTCJul 15, 22:50 UTC3h 15m
2026-07-15 ASA348 ATL → SEA Jul 15, 13:05 UTCJul 15, 17:30 UTC4h 25m
2026-07-15 ASA348 ATL → SEA Jul 15, 13:04 UTCJul 15, 17:18 UTC4h 14m
2026-07-14 ASA727 SEA → ATL Jul 14, 23:50 UTCJul 15, 04:15 UTC4h 25m
2026-07-14 ASA676 LAS → SEA Jul 14, 20:10 UTCJul 14, 21:55 UTC1h 45m

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 N277AK page for operator, model, and routing details .

Mode-S A2C087 frequently asked

What is Mode-S code A2C087?
A2C087 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N277AK.
Where is Mode-S A2C087 registered?
Mode-S code A2C087 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 A2C087 broadcasting right now?
Yes. Mode-S A2C087 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A2C087, octal 50540207, decimal 10,666,119.
What flights does A2C087 operate?
Mode-S A2C087 has broadcast 20 distinct callsigns, including ASA412, ASA365, ASA25, ASA409, ASA352.