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sensors Mode-S transponder

A87428

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N644AS · BOEING 737-700 · operated by ALASKA AIRLINES INC

Hex
A87428
Octal
52072050
Decimal
11,039,784
Country
US
Tail
N644AS
Type
B737
No current signal · last broadcast 2h ago
Flights observed
580
Distinct callsigns
20
Country
US
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S A87428.

Country allocation

The ICAO 24-bit address A87428 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
ASA66 Alaska Airlines 35 2026-06-28
ASA64 Alaska Airlines 34 2026-06-08
ASA65 - 31 2026-07-05
ASA73 - 28 2026-07-15
ASA62 Alaska Airlines 27 2026-06-08
ASA61 - 27 2026-07-11
ASA70 - 23 2026-07-15
ASA55 - 13 2026-07-13
ASA1415 - 12 2026-07-17
ASA607 Alaska Airlines 10 2026-05-09
ASA288 Alaska Airlines 10 2026-06-09
ASA1544 Alaska Airlines 10 2026-07-01
ASA374 Alaska Airlines 9 2026-05-27
ASA1552 Alaska Airlines 9 2026-07-17
ASA67 Alaska Airlines 8 2026-05-24
ASA44 - 8 2026-07-13
ASA310 Alaska Airlines 8 2026-06-07
ASA273 Alaska Airlines 8 2026-05-11
ASA601 Alaska Airlines 7 2026-05-11
ASA43 - 7 2026-07-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-18 ASA1613 JNU → ANC Jul 18, 03:05 UTCJul 18, 04:20 UTC1h 15m
2026-07-18 ASA1537 SEA → MSO Jul 18, 00:25 UTCJul 18, 01:50 UTC1h 25m
2026-07-18 ASA1537 SEA → MSO Jul 18, 00:22 UTCJul 18, 01:49 UTC1h 27m
2026-07-17 ASA1415 FAI → ANC Jul 17, 21:51 UTCJul 17, 22:27 UTC36m
2026-07-17 ASA1415 - Jul 17, 21:44 UTCJul 17, 22:29 UTC45m
2026-07-17 ASA1552 SEA → FAI Jul 17, 17:25 UTCJul 17, 20:35 UTC3h 10m
2026-07-17 ASA272 ANC → SEA Jul 17, 00:50 UTCJul 17, 03:59 UTC3h 10m
2026-07-16 ASA1415 - Jul 16, 22:49 UTCJul 16, 23:35 UTC45m
2026-07-16 ASA1552 SEA → FAI Jul 16, 18:19 UTCJul 16, 21:50 UTC3h 30m
2026-07-16 ASA719 SLC → SEA Jul 16, 03:30 UTCJul 16, 05:05 UTC1h 35m
2026-07-16 ASA373 SEA → SLC Jul 16, 00:28 UTCJul 16, 01:43 UTC1h 15m
2026-07-16 ASA373 - Jul 16, 00:10 UTCJul 16, 01:55 UTC1h 45m
2026-07-15 ASA48 - Jul 15, 19:45 UTCJul 15, 22:45 UTC3h 0m
2026-07-15 73 - Jul 15, 16:30 UTCJul 15, 17:55 UTC1h 25m
2026-07-15 ASA73 - Jul 15, 15:15 UTCJul 15, 15:30 UTC15m
2026-07-15 AS70 - Jul 15, 06:20 UTCJul 15, 06:35 UTC15m
2026-07-15 ASA70 - Jul 15, 04:05 UTCJul 15, 05:20 UTC1h 15m
2026-07-15 ASA755 DLG → ANC Jul 15, 01:16 UTCJul 15, 01:43 UTC27m
2026-07-15 ASA755 - Jul 15, 01:00 UTCJul 15, 01:50 UTC50m
2026-07-14 ASA754 - Jul 14, 22:55 UTCJul 14, 23:45 UTC50m
2026-07-14 ASA1528 OTZ → ANC Jul 14, 19:30 UTCJul 14, 20:45 UTC1h 15m
2026-07-14 ASA1527 ANC → OTZ Jul 14, 17:00 UTCJul 14, 18:15 UTC1h 15m
2026-07-14 ASA1613 - Jul 14, 03:35 UTCJul 14, 05:10 UTC1h 35m
2026-07-14 ASA1537 - Jul 14, 01:10 UTCJul 14, 02:25 UTC1h 15m
2026-07-13 ASA44 - Jul 13, 22:50 UTCJul 13, 23:45 UTC55m
2026-07-13 ASA44 - Jul 13, 22:52 UTCJul 13, 23:34 UTC42m
2026-07-13 ASA43 - Jul 13, 19:15 UTCJul 13, 20:05 UTC50m
2026-07-13 ASA55 ANC → ANC Jul 13, 13:50 UTCJul 13, 17:40 UTC3h 50m
2026-07-13 ASA352 AKN → ANC Jul 13, 02:05 UTCJul 13, 03:01 UTC55m
2026-07-12 ASA351 ANC → AKN Jul 12, 23:55 UTCJul 13, 00:45 UTC50m
2026-07-12 ASA1415 - Jul 12, 21:40 UTCJul 12, 22:30 UTC50m
2026-07-12 ASA1415 FAI → ANC Jul 12, 21:40 UTCJul 12, 22:29 UTC49m
2026-07-12 ASA1552 SEA → FAI Jul 12, 17:10 UTCJul 12, 20:25 UTC3h 15m
2026-07-12 ASA1554 - Jul 12, 13:01 UTCJul 12, 14:55 UTC1h 55m
2026-07-12 ASA71 - Jul 12, 04:35 UTCJul 12, 06:30 UTC1h 55m
2026-07-12 ASA272 - Jul 12, 00:01 UTCJul 12, 03:10 UTC3h 10m
2026-07-11 ASA61 - Jul 11, 21:05 UTCJul 11, 21:35 UTC30m
2026-07-11 ASA61 YAK → CDV Jul 11, 19:25 UTCJul 11, 20:00 UTC35m
2026-07-11 ASA61 - Jul 11, 17:45 UTCJul 11, 18:20 UTC35m
2026-07-11 ASA61 - Jul 11, 14:25 UTCJul 11, 16:20 UTC1h 55m
2026-07-11 ASA445 - Jul 11, 04:45 UTCJul 11, 06:45 UTC2h 0m
2026-07-11 ASA764 - Jul 11, 00:25 UTCJul 11, 00:35 UTC10m
2026-07-10 ASA435 - Jul 10, 21:10 UTCJul 10, 23:05 UTC1h 55m
2026-07-10 ASA60 - Jul 10, 17:40 UTCJul 10, 19:10 UTC1h 30m
2026-07-10 ASA60 - Jul 10, 15:45 UTCJul 10, 16:25 UTC40m
2026-07-10 ASA69 - Jul 10, 04:35 UTCJul 10, 05:05 UTC30m
2026-07-10 ASA69 - Jul 10, 02:00 UTCJul 10, 03:25 UTC1h 25m
2026-07-09 ASA1839 FAI → SEA Jul 9, 20:28 UTCJul 9, 23:17 UTC2h 49m
2026-07-09 ASA1839 - Jul 9, 20:05 UTCJul 9, 20:10 UTC5m
2026-07-09 ASA466 PDX → DFW Jul 9, 18:20 UTCJul 9, 19:05 UTC45m

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 N644AS page for operator, model, and routing details .

Mode-S A87428 frequently asked

What is Mode-S code A87428?
A87428 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N644AS.
Where is Mode-S A87428 registered?
Mode-S code A87428 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 A87428 broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A87428, octal 52072050, decimal 11,039,784.
What flights does A87428 operate?
Mode-S A87428 has broadcast 20 distinct callsigns, including ASA66, ASA64, ASA65, ASA73, ASA62.