Apparatus

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sensors Mode-S transponder

AD4AFB

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N956AK · BOEING 737 MAX 9 · operated by BANK OF UTAH TRUSTEE

Hex
AD4AFB
Octal
53245373
Decimal
11,356,923
Country
US
Tail
N956AK
Type
B39M
No current signal · last broadcast Jul 26, 22:45 UTC
Flights observed
426
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:45 UTC

Last known position

Most recent position reported by Mode-S AD4AFB.

Country allocation

The ICAO 24-bit address AD4AFB 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
ASA617 Alaska Airlines 7 2026-05-23
ASA508 - 6 2026-06-22
ASA787 Alaska Airlines 5 2026-05-20
ASA502 Alaska Airlines 5 2026-06-08
ASA433 Alaska Airlines 5 2026-05-28
ASA727 - 4 2026-07-07
ASA639 Alaska Airlines 4 2026-04-14
ASA287 - 4 2026-07-09
ASA22 Alaska Airlines 4 2026-06-10
ASA1332 - 4 2026-06-20
ASA795 Alaska Airlines 3 2026-06-15
ASA779 - 3 2026-07-06
ASA776 - 3 2026-07-05
ASA77 Alaska Airlines 3 2026-07-24
ASA751 Alaska Airlines 3 2026-05-19
ASA657 Alaska Airlines 3 2026-06-04
ASA647 - 3 2026-07-02
ASA643 - 3 2026-07-11
ASA561 Alaska Airlines 3 2026-06-04
ASA500 - 3 2026-07-12

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ASA1538 SLC → SEA Jul 26, 22:35 UTCJul 26, 22:45 UTC10m
2026-07-26 ASA1635 PDX → STL Jul 26, 18:00 UTCJul 26, 21:10 UTC3h 10m
2026-07-26 ASA1626 DEN → PDX Jul 26, 14:15 UTCJul 26, 16:30 UTC2h 15m
2026-07-26 ASA752 SEA → PSP Jul 26, 07:20 UTCJul 26, 12:15 UTC4h 55m
2026-07-26 ASA46 BET → ANC Jul 26, 04:40 UTCJul 26, 05:25 UTC45m
2026-07-26 ASA45 ANC → BET Jul 26, 02:30 UTCJul 26, 03:10 UTC40m
2026-07-25 ASA1565 PDX → ANC Jul 25, 21:50 UTCJul 26, 00:52 UTC3h 2m
2026-07-25 ASA1565 PDX → ANC Jul 25, 21:45 UTCJul 26, 00:50 UTC3h 5m
2026-07-25 ASA1467 LAS → PDX Jul 25, 18:10 UTCJul 25, 19:50 UTC1h 40m
2026-07-25 ASA627 PDX → LAS Jul 25, 14:50 UTCJul 25, 16:45 UTC1h 55m
2026-07-25 ASA710 OGG → SFO Jul 25, 12:10 UTCJul 25, 13:00 UTC50m
2026-07-25 ASA710 OGG → SFO Jul 25, 12:09 UTCJul 25, 12:57 UTC48m
2026-07-25 ASA1356 SFO → LTO Jul 25, 05:10 UTCJul 25, 05:50 UTC40m
2026-07-25 ASA1356 SFO → LTO Jul 25, 05:05 UTCJul 25, 05:49 UTC44m
2026-07-24 ASA1421 SNA → SEA Jul 24, 23:30 UTCJul 25, 03:35 UTC4h 5m
2026-07-24 ASA438 SEA → IAH Jul 24, 18:15 UTCJul 24, 22:00 UTC3h 45m
2026-07-24 ASA78 SEA → ANC Jul 24, 11:40 UTCJul 24, 16:30 UTC4h 50m
2026-07-24 ASA77 SFO → LAX Jul 24, 05:50 UTCJul 24, 09:45 UTC3h 55m
2026-07-23 ASA462 SEA → CMH Jul 23, 22:00 UTCJul 24, 03:30 UTC5h 30m
2026-07-23 ASA297 SAN → EWR Jul 23, 15:10 UTCJul 23, 19:55 UTC4h 45m
2026-07-23 ASA397 MCO → SAN Jul 23, 00:40 UTCJul 23, 04:55 UTC4h 15m
2026-07-22 ASA396 - Jul 22, 18:25 UTCJul 22, 22:50 UTC4h 25m
2026-07-22 ASA1680 SMF → SAN Jul 22, 14:35 UTCJul 22, 15:45 UTC1h 10m
2026-07-22 ASA638 SEA → TUS Jul 22, 02:45 UTCJul 22, 04:15 UTC1h 30m
2026-07-21 ASA507 - Jul 21, 20:15 UTCJul 22, 00:05 UTC3h 50m
2026-07-21 ASA507 SEA → MKE Jul 21, 15:25 UTCJul 21, 18:30 UTC3h 5m
2026-07-21 ASA17 JFK → SEA Jul 21, 01:20 UTCJul 21, 06:50 UTC5h 30m
2026-07-20 ASA18 PDX → JFK Jul 20, 18:25 UTCJul 20, 22:40 UTC4h 15m
2026-07-20 ASA1629 LAS → PDX Jul 20, 14:20 UTCJul 20, 16:00 UTC1h 40m
2026-07-20 ASA605 - Jul 20, 01:25 UTCJul 20, 03:35 UTC2h 10m
2026-07-19 ASA674 PHX → PAE Jul 19, 21:46 UTCJul 20, 00:04 UTC2h 18m
2026-07-19 ASA674 PHX → PAE Jul 19, 21:35 UTCJul 20, 00:05 UTC2h 30m
2026-07-19 ASA716 SFO → SAN Jul 19, 18:00 UTCJul 19, 20:10 UTC2h 10m
2026-07-19 ASA1490 OGG → PDX Jul 19, 01:45 UTCJul 19, 02:35 UTC50m
2026-07-18 ASA739 - Jul 18, 14:40 UTCJul 18, 15:25 UTC45m
2026-07-18 ASA1457 SEA → PDX Jul 18, 05:55 UTCJul 18, 06:25 UTC30m
2026-07-18 ASA417 - Jul 18, 01:25 UTCJul 18, 03:40 UTC2h 16m
2026-07-17 ASA1395 - Jul 17, 22:35 UTCJul 17, 23:14 UTC40m
2026-07-17 ASA1414 SAN → SJD Jul 17, 18:14 UTCJul 17, 19:50 UTC1h 36m
2026-07-17 ASA1414 - Jul 17, 18:15 UTCJul 17, 18:44 UTC30m
2026-07-17 ASA474 RDU → SAN Jul 17, 00:30 UTCJul 17, 04:54 UTC4h 25m
2026-07-16 ASA434 SAN → RDU Jul 16, 17:45 UTCJul 16, 22:19 UTC4h 35m
2026-07-16 ASA1623 SJC → SAN Jul 16, 15:20 UTCJul 16, 16:26 UTC1h 6m
2026-07-16 ASA1623 SJC → SAN Jul 16, 15:19 UTCJul 16, 16:30 UTC1h 10m
2026-07-16 ASA523 SEA → SJC Jul 16, 04:55 UTCJul 16, 06:50 UTC1h 55m
2026-07-15 ASA569 MSY → SEA Jul 15, 22:40 UTCJul 16, 02:55 UTC4h 15m
2026-07-15 ASA568 SEA → MSY Jul 15, 17:02 UTCJul 15, 21:12 UTC4h 10m
2026-07-15 ASA568 SEA → MSY Jul 15, 17:05 UTCJul 15, 21:15 UTC4h 10m
2026-07-15 ASA473 STL → SEA Jul 15, 11:20 UTCJul 15, 14:55 UTC3h 35m
2026-07-15 ASA615 SEA → STL Jul 15, 01:40 UTCJul 15, 05:05 UTC3h 25m

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 N956AK page for operator, model, and routing details .

Mode-S AD4AFB frequently asked

What is Mode-S code AD4AFB?
AD4AFB is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N956AK.
Where is Mode-S AD4AFB registered?
Mode-S code AD4AFB 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 AD4AFB broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 22:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AD4AFB, octal 53245373, decimal 11,356,923.
What flights does AD4AFB operate?
Mode-S AD4AFB has broadcast 20 distinct callsigns, including ASA617, ASA508, ASA787, ASA502, ASA433.