Apparatus

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sensors Mode-S transponder

AD438D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N954AK · BOEING 737 MAX 9 · operated by ALASKA AIRLINES INC

Hex
AD438D
Octal
53241615
Decimal
11,355,021
Country
US
Tail
N954AK
Type
B39M
No current signal · last broadcast 1h ago
Flights observed
380
Distinct callsigns
20
Country
US
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S AD438D.

Country allocation

The ICAO 24-bit address AD438D 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
ASA695 Alaska Airlines 5 2026-06-28
ASA433 Alaska Airlines 5 2026-06-10
ASA311 Alaska Airlines 5 2026-07-07
ASA540 - 4 2026-06-30
ASA462 - 4 2026-06-24
ASA239 - 4 2026-07-08
ASA17 - 4 2026-04-13
ASA1396 - 4 2026-06-30
ASA771 Alaska Airlines 3 2026-06-06
ASA757 - 3 2026-06-16
ASA756 - 3 2026-06-16
ASA737 Alaska Airlines 3 2026-05-23
ASA715 - 3 2026-07-04
ASA662 Alaska Airlines 3 2026-04-18
ASA639 - 3 2026-04-13
ASA569 Alaska Airlines 3 2026-04-20
ASA538 - 3 2026-07-14
ASA460 - 3 2026-07-07
ASA456 - 3 2026-07-04
ASA316 Alaska Airlines 3 2026-05-24

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 ASA538 SEA → ORD Jul 14, 01:30 UTCJul 14, 04:50 UTC3h 20m
2026-07-13 ASA790 SFO → SEA Jul 13, 22:35 UTCJul 14, 00:00 UTC1h 25m
2026-07-13 ASA570 LAS → SFO Jul 13, 17:45 UTCJul 13, 19:00 UTC1h 15m
2026-07-13 ASA718 SFO → LAS Jul 13, 14:40 UTCJul 13, 15:50 UTC1h 10m
2026-07-13 ASA291 - Jul 13, 06:20 UTCJul 13, 07:20 UTC1h 0m
2026-07-13 ASA203 - Jul 13, 02:40 UTCJul 13, 03:30 UTC50m
2026-07-12 ASA245 - Jul 12, 15:25 UTCJul 12, 16:15 UTC50m
2026-07-12 ASA614 - Jul 12, 03:20 UTCJul 12, 05:20 UTC2h 0m
2026-07-11 ASA1300 SEA → LAX Jul 11, 23:30 UTCJul 12, 01:55 UTC2h 25m
2026-07-11 ASA415 DFW → SEA Jul 11, 18:20 UTCJul 11, 21:55 UTC3h 35m
2026-07-11 ASA415 DFW → SEA Jul 11, 18:20 UTCJul 11, 21:46 UTC3h 26m
2026-07-11 ASA414 SEA → DFW Jul 11, 13:05 UTCJul 11, 16:30 UTC3h 25m
2026-07-11 ASA244 - Jul 11, 06:20 UTCJul 11, 07:00 UTC40m
2026-07-10 ASA254 - Jul 10, 19:00 UTCJul 10, 19:35 UTC35m
2026-07-10 ASA708 MCO → SAN Jul 10, 12:00 UTCJul 10, 16:20 UTC4h 20m
2026-07-10 ASA394 SEA → MCO Jul 10, 05:30 UTCJul 10, 10:20 UTC4h 50m
2026-07-09 ASA787 - Jul 9, 22:20 UTCJul 10, 03:50 UTC5h 30m
2026-07-09 ASA787 - Jul 9, 16:00 UTCJul 9, 20:40 UTC4h 40m
2026-07-09 ASA1444 SLC → SEA Jul 9, 12:40 UTCJul 9, 14:20 UTC1h 40m
2026-07-09 ASA1459 SEA → SLC Jul 9, 03:50 UTCJul 9, 05:25 UTC1h 35m
2026-07-08 ASA356 EWR → SEA Jul 8, 20:50 UTCJul 9, 02:15 UTC5h 25m
2026-07-08 ASA239 SEA → EWR Jul 8, 14:10 UTCJul 8, 18:45 UTC4h 35m
2026-07-08 ASA239 SEA → EWR Jul 8, 14:10 UTCJul 8, 18:34 UTC4h 24m
2026-07-07 ASA510 MSP → SEA Jul 7, 22:25 UTCJul 8, 01:40 UTC3h 15m
2026-07-07 ASA1429 SJD → SFO Jul 7, 18:05 UTCJul 7, 20:55 UTC2h 50m
2026-07-07 ASA311 SEA → SFO Jul 7, 10:33 UTCJul 7, 16:00 UTC5h 27m
2026-07-07 ASA311 SEA → SFO Jul 7, 10:30 UTCJul 7, 15:55 UTC5h 25m
2026-07-07 ASA460 SEA → BOS Jul 7, 01:45 UTCJul 7, 06:45 UTC5h 0m
2026-07-06 ASA402 ANC → SEA Jul 6, 21:17 UTCJul 7, 00:09 UTC2h 52m
2026-07-06 ASA402 ANC → SEA Jul 6, 21:10 UTCJul 7, 00:25 UTC3h 15m
2026-07-06 ASA53 - Jul 6, 14:45 UTCJul 6, 19:30 UTC4h 45m
2026-07-06 ASA63 SFO → LAX Jul 6, 05:15 UTCJul 6, 07:30 UTC2h 15m
2026-07-06 ASA641 - Jul 6, 01:10 UTCJul 6, 03:45 UTC2h 35m
2026-07-05 ASA648 SEA → TUS Jul 5, 21:20 UTCJul 6, 00:00 UTC2h 40m
2026-07-04 ASA456 - Jul 4, 22:05 UTCJul 4, 23:55 UTC1h 50m
2026-07-04 ASA209 LAX → SFO Jul 4, 18:30 UTCJul 4, 20:30 UTC2h 0m
2026-07-04 ASA715 ORD → SEA Jul 4, 12:20 UTCJul 4, 16:15 UTC3h 55m
2026-07-04 ASA538 SEA → ORD Jul 4, 03:00 UTCJul 4, 06:45 UTC3h 45m
2026-07-03 ASA1473 KOA → SEA Jul 3, 15:50 UTCJul 3, 18:05 UTC2h 15m
2026-07-03 ASA1473 KOA → SEA Jul 3, 15:35 UTCJul 3, 15:45 UTC10m
2026-07-02 ASA397 MCO → SAN Jul 2, 23:50 UTCJul 3, 04:10 UTC4h 20m
2026-07-02 ASA396 PDX → SJC Jul 2, 17:55 UTCJul 2, 22:15 UTC4h 20m
2026-07-02 ASA1680 SMF → SAN Jul 2, 15:10 UTCJul 2, 16:20 UTC1h 10m
2026-07-02 ASA638 SEA → TUS Jul 2, 02:40 UTCJul 2, 04:00 UTC1h 20m
2026-07-01 ASA405 SEA → OKC Jul 1, 20:25 UTCJul 1, 23:50 UTC3h 25m
2026-07-01 ASA405 SEA → OKC Jul 1, 15:45 UTCJul 1, 18:55 UTC3h 10m
2026-07-01 ASA499 PDX → SEA Jul 1, 13:35 UTCJul 1, 14:05 UTC30m
2026-06-30 ASA1396 AUS → PDX Jun 30, 23:11 UTCJul 1, 02:34 UTC3h 23m
2026-06-30 ASA1396 AUS → PDX Jun 30, 23:05 UTCJul 1, 02:45 UTC3h 40m
2026-06-30 ASA540 PDX → AUS Jun 30, 18:10 UTCJun 30, 21:40 UTC3h 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 N954AK page for operator, model, and routing details .

Mode-S AD438D frequently asked

What is Mode-S code AD438D?
AD438D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N954AK.
Where is Mode-S AD438D registered?
Mode-S code AD438D 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 AD438D broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AD438D, octal 53241615, decimal 11,355,021.
What flights does AD438D operate?
Mode-S AD438D has broadcast 20 distinct callsigns, including ASA695, ASA433, ASA311, ASA540, ASA462.