Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A7197D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N557AS · BOEING 737-800 · operated by ALASKA AIRLINES INC

Hex
A7197D
Octal
51614575
Decimal
10,951,037
Country
US
Tail
N557AS
Type
B738
No current signal · last broadcast 4h ago
Flights observed
369
Distinct callsigns
20
Country
US
Last broadcast
4h ago

Last known position

Most recent position reported by Mode-S A7197D.

Country allocation

The ICAO 24-bit address A7197D 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
ASA660 - 7 2026-07-01
ASA5 Alaska Airlines 5 2026-06-01
ASA237 - 5 2026-06-26
ASA213 Alaska Airlines 5 2026-06-26
ASA97 Alaska Airlines 4 2026-06-24
ASA697 - 4 2026-06-29
ASA6 Alaska Airlines 4 2026-05-31
ASA508 - 4 2026-06-28
ASA506 Alaska Airlines 4 2026-06-07
ASA225 Alaska Airlines 4 2026-05-21
ASA14 Alaska Airlines 4 2026-05-22
ASA9801 Alaska Airlines 3 2026-04-13
ASA759 Alaska Airlines 3 2026-06-07
ASA731 - 3 2026-07-08
ASA676 Alaska Airlines 3 2026-04-24
ASA549 Alaska Airlines 3 2026-05-07
ASA541 Alaska Airlines 3 2026-04-14
ASA49 Alaska Airlines 3 2026-05-17
ASA452 Alaska Airlines 3 2026-06-07
ASA315 - 3 2026-07-01

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 ASA642 SEA → DEN Jul 14, 03:55 UTCJul 14, 06:10 UTC2h 15m
2026-07-13 ASA407 - Jul 13, 21:10 UTCJul 14, 00:55 UTC3h 45m
2026-07-13 ASA265 SEA → ORD Jul 13, 15:55 UTCJul 13, 19:45 UTC3h 50m
2026-07-12 ASA313 - Jul 12, 21:45 UTCJul 13, 02:20 UTC4h 35m
2026-07-12 ASA313 - Jul 12, 16:40 UTCJul 12, 20:15 UTC3h 35m
2026-07-11 ASA652 - Jul 11, 03:05 UTCJul 11, 04:55 UTC1h 50m
2026-07-10 ASA633 - Jul 10, 19:20 UTCJul 10, 21:00 UTC1h 40m
2026-07-10 ASA587 ORD → SEA Jul 10, 13:30 UTCJul 10, 17:20 UTC3h 50m
2026-07-10 ASA1724 ANC → ORD Jul 10, 06:05 UTCJul 10, 11:45 UTC5h 40m
2026-07-09 ASA232 - Jul 9, 17:20 UTCJul 9, 18:00 UTC40m
2026-07-09 ASA231 LAS → SFO Jul 9, 15:35 UTCJul 9, 16:15 UTC40m
2026-07-09 ASA1532 PHX → ANC Jul 9, 01:55 UTCJul 9, 07:30 UTC5h 35m
2026-07-09 ASA1532 PHX → ANC Jul 9, 01:54 UTCJul 9, 07:19 UTC5h 25m
2026-07-08 ASA731 PDX → PHX Jul 8, 21:55 UTCJul 9, 00:10 UTC2h 15m
2026-07-08 ASA731 PDX → PHX Jul 8, 22:05 UTCJul 9, 00:05 UTC2h 0m
2026-07-08 ASA1699 ONT → PDX Jul 8, 18:00 UTCJul 8, 19:50 UTC1h 50m
2026-07-08 ASA1699 ONT → PDX Jul 8, 18:14 UTCJul 8, 19:47 UTC1h 33m
2026-07-08 ASA1449 PDX → ONT Jul 8, 14:45 UTCJul 8, 16:45 UTC2h 0m
2026-07-08 ASA1566 BOI → PDX Jul 8, 12:05 UTCJul 8, 13:00 UTC55m
2026-07-08 ASA463 SEA → BOI Jul 8, 06:05 UTCJul 8, 07:05 UTC1h 0m
2026-07-08 ASA481 SEA → BZE Jul 8, 02:05 UTCJul 8, 03:13 UTC1h 8m
2026-07-08 ASA481 SEA → BZE Jul 8, 01:50 UTCJul 8, 03:30 UTC1h 40m
2026-07-07 ASA319 SEA → SJC Jul 7, 23:00 UTCJul 8, 00:50 UTC1h 50m
2026-07-07 ASA1322 STS → SEA Jul 7, 20:00 UTCJul 7, 21:25 UTC1h 25m
2026-07-07 ASA1321 SEA → STS Jul 7, 17:22 UTCJul 7, 18:47 UTC1h 25m
2026-07-07 ASA1321 - Jul 7, 17:15 UTCJul 7, 18:45 UTC1h 30m
2026-07-07 ASA1365 - Jul 7, 13:30 UTCJul 7, 15:35 UTC2h 5m
2026-07-07 ASA1365 LAX → SEA Jul 7, 13:26 UTCJul 7, 15:25 UTC1h 59m
2026-07-07 ASA287 EWR → LAX Jul 7, 00:50 UTCJul 7, 06:05 UTC5h 15m
2026-07-06 ASA477 SEA → EWR Jul 6, 17:55 UTCJul 6, 22:50 UTC4h 55m
2026-07-06 ASA1365 - Jul 6, 13:30 UTCJul 6, 15:35 UTC2h 5m
2026-07-06 ASA287 EWR → LAX Jul 6, 00:55 UTCJul 6, 06:15 UTC5h 20m
2026-07-05 ASA477 SEA → EWR Jul 5, 18:00 UTCJul 5, 22:35 UTC4h 35m
2026-07-05 ASA440 - Jul 5, 11:15 UTCJul 5, 15:10 UTC3h 55m
2026-07-04 ASA507 SNA → SEA Jul 4, 15:15 UTCJul 4, 18:40 UTC3h 25m
2026-07-04 ASA430 PDX → SEA Jul 4, 01:45 UTCJul 4, 02:15 UTC30m
2026-07-03 ASA712 - Jul 3, 22:25 UTCJul 4, 00:35 UTC2h 10m
2026-07-03 ASA588 - Jul 3, 19:20 UTCJul 3, 21:20 UTC2h 0m
2026-07-03 ASA1629 LAS → PDX Jul 3, 14:15 UTCJul 3, 16:10 UTC1h 55m
2026-07-03 ASA1629 LAS → PDX Jul 3, 14:12 UTCJul 3, 16:06 UTC1h 54m
2026-07-03 ASA704 SEA → LAS Jul 3, 04:05 UTCJul 3, 06:00 UTC1h 55m
2026-07-02 ASA31 JFK → SEA Jul 2, 20:55 UTCJul 3, 02:30 UTC5h 35m
2026-07-02 ASA26 SEA → JFK Jul 2, 14:10 UTCJul 2, 19:05 UTC4h 55m
2026-07-02 ASA1518 ANC → SEA Jul 2, 02:50 UTCJul 2, 05:35 UTC2h 45m
2026-07-01 ASA660 SEA → ANC Jul 1, 22:15 UTCJul 2, 01:30 UTC3h 15m
2026-07-01 ASA315 ANC → SEA Jul 1, 17:10 UTCJul 1, 20:05 UTC2h 55m
2026-07-01 ASA771 SEA → ANC Jul 1, 05:15 UTCJul 1, 08:30 UTC3h 15m
2026-06-30 ASA322 DFW → SEA Jun 30, 23:45 UTCJul 1, 03:40 UTC3h 55m
2026-06-30 ASA341 SEA → DFW Jun 30, 18:35 UTCJun 30, 22:05 UTC3h 30m
2026-06-30 ASA341 SEA → DFW Jun 30, 18:31 UTCJun 30, 21:56 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 N557AS page for operator, model, and routing details .

Mode-S A7197D frequently asked

What is Mode-S code A7197D?
A7197D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N557AS.
Where is Mode-S A7197D registered?
Mode-S code A7197D 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 A7197D broadcasting right now?
No active broadcast right now. Last signal was 4h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A7197D, octal 51614575, decimal 10,951,037.
What flights does A7197D operate?
Mode-S A7197D has broadcast 20 distinct callsigns, including ASA660, ASA5, ASA237, ASA213, ASA97.