Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

AD1857

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N943AK · operated by ALASKA AIRLINES INC

Hex
AD1857
Octal
53214127
Decimal
11,343,959
Country
US
Tail
N943AK
Type
B39M
Broadcasting now · callsign ASA50 · 7,800 ft
Flights observed
350
Distinct callsigns
20
Country
US
Last broadcast
6h ago

Current position

AD1857 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address AD1857 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
ASA626 - 7 2026-06-14
ASA581 - 6 2026-07-01
ASA50 Alaska Airlines 6 2026-05-10
ASA203 - 6 2026-07-06
ASA221 Alaska Airlines 5 2026-05-10
ASA755 Alaska Airlines 4 2026-06-01
ASA508 Alaska Airlines 4 2026-05-21
ASA49 - 4 2026-07-14
ASA418 Alaska Airlines 4 2026-05-15
ASA317 - 4 2026-06-26
ASA1403 Alaska Airlines 4 2026-04-17
ASA84 Alaska Airlines 3 2026-05-25
ASA784 Alaska Airlines 3 2026-06-04
ASA763 - 3 2026-07-01
ASA602 - 3 2026-06-26
ASA549 Alaska Airlines 3 2026-04-23
ASA544 Alaska Airlines 3 2026-06-23
ASA522 - 3 2026-07-13
ASA375 Alaska Airlines 3 2026-06-11
ASA364 - 3 2026-04-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 ASA49 - Jul 14, 00:20 UTCJul 14, 01:10 UTC50m
2026-07-13 ASA83 SEA → ANC Jul 13, 19:00 UTCJul 13, 22:15 UTC3h 15m
2026-07-13 ASA277 BUR → SEA Jul 13, 12:45 UTCJul 13, 16:55 UTC4h 10m
2026-07-13 ASA277 BUR → SEA Jul 13, 12:08 UTCJul 13, 16:46 UTC4h 38m
2026-07-13 ASA277 BUR → SEA Jul 13, 11:50 UTCJul 13, 12:40 UTC50m
2026-07-13 ASA522 SEA → PHL Jul 13, 05:40 UTCJul 13, 10:15 UTC4h 35m
2026-07-13 ASA417 SAN → SEA Jul 13, 00:45 UTCJul 13, 02:50 UTC2h 5m
2026-07-12 ASA551 DFW → SAN Jul 12, 20:30 UTCJul 12, 22:55 UTC2h 25m
2026-07-12 ASA340 SEA → DFW Jul 12, 15:40 UTCJul 12, 19:05 UTC3h 25m
2026-07-12 ASA279 GEG → SEA Jul 12, 13:25 UTCJul 12, 14:05 UTC40m
2026-07-12 ASA1614 - Jul 12, 02:55 UTCJul 12, 04:45 UTC1h 50m
2026-07-11 ASA1406 - Jul 11, 19:20 UTCJul 12, 00:50 UTC5h 30m
2026-07-11 ASA673 GEG → SAN Jul 11, 15:20 UTCJul 11, 17:45 UTC2h 25m
2026-07-11 ASA1342 - Jul 11, 03:30 UTCJul 11, 04:05 UTC35m
2026-07-10 ASA494 SAT → SEA Jul 10, 22:00 UTCJul 11, 01:55 UTC3h 55m
2026-07-10 ASA494 - Jul 10, 17:05 UTCJul 10, 20:35 UTC3h 30m
2026-07-10 ASA701 LAS → SEA Jul 10, 13:15 UTCJul 10, 15:25 UTC2h 10m
2026-07-10 ASA468 - Jul 10, 06:30 UTCJul 10, 07:35 UTC1h 5m
2026-07-10 ASA1601 LAX → SFO Jul 10, 04:20 UTCJul 10, 05:15 UTC55m
2026-07-09 ASA1406 - Jul 9, 19:35 UTCJul 10, 01:00 UTC5h 25m
2026-07-09 ASA673 - Jul 9, 15:30 UTCJul 9, 17:45 UTC2h 15m
2026-07-09 ASA1342 SEA → GEG Jul 9, 03:30 UTCJul 9, 04:05 UTC35m
2026-07-09 ASA289 BFI → SEA Jul 9, 01:55 UTCJul 9, 02:00 UTC5m
2026-07-08 ASA289 PHX → SEA Jul 8, 23:27 UTCJul 9, 01:38 UTC2h 11m
2026-07-08 ASA289 PHX → SEA Jul 8, 23:20 UTCJul 9, 02:00 UTC2h 40m
2026-07-08 ASA1371 SEA → PHX Jul 8, 19:40 UTCJul 8, 22:00 UTC2h 20m
2026-07-08 ASA348 ATL → SEA Jul 8, 13:05 UTCJul 8, 17:50 UTC4h 45m
2026-07-08 ASA464 SEA → ATL Jul 8, 06:50 UTCJul 8, 11:10 UTC4h 20m
2026-07-08 ASA205 - Jul 8, 04:10 UTCJul 8, 05:05 UTC55m
2026-07-07 ASA205 - Jul 7, 23:30 UTCJul 7, 23:50 UTC20m
2026-07-07 ASA222 - Jul 7, 21:55 UTCJul 7, 22:05 UTC10m
2026-07-07 ASA222 SAN → KOA Jul 7, 16:50 UTCJul 7, 22:03 UTC5h 13m
2026-07-07 ASA222 - Jul 7, 16:55 UTCJul 7, 17:30 UTC35m
2026-07-07 ASA474 RDU → SAN Jul 7, 01:15 UTCJul 7, 05:50 UTC4h 35m
2026-07-06 ASA434 - Jul 6, 17:30 UTCJul 6, 21:50 UTC4h 20m
2026-07-06 ASA1624 SAN → SJC Jul 6, 05:54 UTCJul 6, 07:06 UTC1h 12m
2026-07-06 ASA203 - Jul 6, 02:30 UTCJul 6, 03:15 UTC45m
2026-07-05 ASA203 OGG → SAN Jul 5, 22:36 UTCJul 6, 21:45 UTC23h 9m
2026-07-05 ASA245 SEA → OGG Jul 5, 15:25 UTCJul 5, 16:15 UTC50m
2026-07-05 ASA206 PDX → SFO Jul 5, 12:00 UTCJul 5, 12:50 UTC50m
2026-07-05 ASA353 - Jul 5, 01:05 UTCJul 5, 01:55 UTC50m
2026-07-04 ASA756 LAS → PDX Jul 4, 21:25 UTCJul 4, 23:15 UTC1h 50m
2026-07-04 ASA757 PDX → LAS Jul 4, 18:20 UTCJul 4, 20:05 UTC1h 45m
2026-07-04 ASA345 IAD → LAX Jul 4, 14:05 UTCJul 4, 15:55 UTC1h 50m
2026-07-04 ASA97 PVR → SJC Jul 4, 04:35 UTCJul 4, 06:30 UTC1h 55m
2026-07-04 ASA1490 - Jul 4, 01:35 UTCJul 4, 02:25 UTC50m
2026-07-03 ASA739 - Jul 3, 14:20 UTCJul 3, 15:05 UTC45m
2026-07-02 ASA301 MCO → PDX Jul 2, 22:30 UTCJul 3, 03:50 UTC5h 20m
2026-07-02 ASA295 SEA → MCO Jul 2, 15:55 UTCJul 2, 20:48 UTC4h 53m
2026-07-02 ASA295 SEA → MCO Jul 2, 15:55 UTCJul 2, 21:05 UTC5h 10m

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 N943AK page for operator, model, and routing details .

Mode-S AD1857 frequently asked

What is Mode-S code AD1857?
AD1857 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N943AK.
Where is Mode-S AD1857 registered?
Mode-S code AD1857 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 AD1857 broadcasting right now?
Yes. Mode-S AD1857 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AD1857, octal 53214127, decimal 11,343,959.
What flights does AD1857 operate?
Mode-S AD1857 has broadcast 20 distinct callsigns, including ASA626, ASA581, ASA50, ASA203, ASA221.