Apparatus

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sensors Mode-S transponder

A125F9

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N173SY · EMBRAER ERJ-170-200 (long wing) · operated by SKYWEST AIRLINES INC

Hex
A125F9
Octal
50222771
Decimal
10,561,017
Country
US
Tail
N173SY
Type
E75L
No current signal · last broadcast Jul 26, 22:15 UTC
Flights observed
651
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:15 UTC

Last known position

Most recent position reported by Mode-S A125F9.

Country allocation

The ICAO 24-bit address A125F9 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
SKW3410 - 9 2026-07-08
SKW3315 SkyWest Airlines 9 2026-07-20
SKW3302 - 9 2026-07-06
SKW3433 SkyWest Airlines 7 2026-07-26
SKW3346 SkyWest Airlines 7 2026-06-11
SKW3324 - 7 2026-07-04
SKW3323 - 7 2026-07-14
SKW3273 SkyWest Airlines 7 2026-05-01
SKW3480 - 6 2026-07-13
SKW3432 - 6 2026-06-21
SKW3398 - 6 2026-07-13
SKW3374 SkyWest Airlines 6 2026-06-07
SKW3369 - 6 2026-07-10
SKW3131 SkyWest Airlines 6 2026-06-12
SKW3061 SkyWest Airlines 6 2026-07-06
SKW3060 - 6 2026-07-06
SKW3047 SkyWest Airlines 6 2026-05-19
SKW3044 - 6 2026-07-11
SKW3024 - 6 2026-07-07
SKW3020 SkyWest Airlines 6 2026-06-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW3120 RNO → PDX Jul 26, 21:50 UTCJul 26, 22:15 UTC25m
2026-07-26 SKW3121 LAX → SFO Jul 26, 19:15 UTCJul 26, 20:15 UTC1h 0m
2026-07-26 SKW3110 LAX → SJC Jul 26, 16:55 UTCJul 26, 17:49 UTC54m
2026-07-26 SKW3110 LAX → SJC Jul 26, 16:45 UTCJul 26, 17:45 UTC1h 0m
2026-07-26 SKW3018 DFW → LAW Jul 26, 13:50 UTCJul 26, 15:25 UTC1h 35m
2026-07-26 SKW3298 LAX → SEA Jul 26, 02:30 UTCJul 26, 04:10 UTC1h 40m
2026-07-26 SKW3433 SFO → LAX Jul 26, 00:35 UTCJul 26, 01:05 UTC30m
2026-07-26 SKW3433 SFO → LAX Jul 26, 00:46 UTCJul 26, 00:59 UTC13m
2026-07-25 SKW3433 SFO → LAX Jul 25, 23:05 UTCJul 25, 23:35 UTC30m
2026-07-25 SKW3360 PDX → SFO Jul 25, 21:00 UTCJul 25, 21:50 UTC50m
2026-07-25 SKW3360 PDX → SFO Jul 25, 18:58 UTCJul 25, 19:35 UTC37m
2026-07-25 SKW3360 PDX → SFO Jul 25, 18:50 UTCJul 25, 19:40 UTC50m
2026-07-25 SKW3284 LAX → PDX Jul 25, 15:00 UTCJul 25, 17:15 UTC2h 15m
2026-07-25 SKW3284 LAX → PDX Jul 25, 15:03 UTCJul 25, 17:10 UTC2h 7m
2026-07-25 SKW3356 PSP → SFO Jul 25, 03:35 UTCJul 25, 04:30 UTC55m
2026-07-25 SKW3248 SJC → SEA Jul 25, 01:15 UTCJul 25, 02:15 UTC1h 0m
2026-07-24 SKW3494 SNA → SFO Jul 24, 23:00 UTCJul 25, 00:10 UTC1h 10m
2026-07-24 SKW3208 JAC → SFO Jul 24, 20:05 UTCJul 24, 22:00 UTC1h 55m
2026-07-24 SKW3468 JAC → SFO Jul 24, 16:35 UTCJul 24, 18:00 UTC1h 25m
2026-07-24 SKW3251 SNA → SFO Jul 24, 14:10 UTCJul 24, 15:15 UTC1h 5m
2026-07-24 SKW3464 SFO → LAX Jul 24, 04:20 UTCJul 24, 05:35 UTC1h 15m
2026-07-24 SKW3232 SAN → SFO Jul 24, 02:20 UTCJul 24, 03:25 UTC1h 5m
2026-07-24 SKW812T FAT → SAN Jul 24, 00:10 UTCJul 24, 01:05 UTC55m
2026-07-23 SKW3389 SAN → SJC Jul 23, 22:20 UTCJul 23, 23:00 UTC40m
2026-07-23 SKW3479 SJC → BOI Jul 23, 20:10 UTCJul 23, 21:25 UTC1h 15m
2026-07-23 SKW3479 SJC → BOI Jul 23, 20:04 UTCJul 23, 21:24 UTC1h 20m
2026-07-23 SKW3342 LAX → SFO Jul 23, 17:45 UTCJul 23, 18:55 UTC1h 10m
2026-07-23 SKW3244 SFO → SNA Jul 23, 13:50 UTCJul 23, 15:00 UTC1h 10m
2026-07-23 SKW3495 EUG → SEA Jul 23, 04:40 UTCJul 23, 05:50 UTC1h 10m
2026-07-23 SKW3492 SNA → SFO Jul 23, 01:40 UTCJul 23, 02:45 UTC1h 5m
2026-07-22 SKW3080 - Jul 22, 23:15 UTCJul 23, 00:25 UTC1h 10m
2026-07-22 SKW3081 - Jul 22, 20:55 UTCJul 22, 21:55 UTC1h 0m
2026-07-22 SKW3025 DEN → SAN Jul 22, 18:15 UTCJul 22, 19:45 UTC1h 30m
2026-07-22 SKW3393 LAX → SFO Jul 22, 14:25 UTCJul 22, 16:00 UTC1h 35m
2026-07-22 SKW3232 SAN → SFO Jul 22, 04:20 UTCJul 22, 05:25 UTC1h 5m
2026-07-22 SKW3232 SAN → SFO Jul 22, 03:25 UTCJul 22, 05:20 UTC1h 55m
2026-07-21 SKW3235 BOI → SAN Jul 21, 14:10 UTCJul 21, 16:10 UTC2h 0m
2026-07-21 SKW3331 BOI → SAN Jul 21, 00:25 UTCJul 21, 02:05 UTC1h 40m
2026-07-21 SKW3331 BOI → SAN Jul 21, 00:31 UTCJul 21, 02:05 UTC1h 34m
2026-07-20 SKW3315 LAX → SEA Jul 20, 13:35 UTCJul 20, 15:00 UTC1h 25m
2026-07-20 SKW3086 GRK → DFW Jul 20, 01:50 UTCJul 20, 02:50 UTC1h 0m
2026-07-20 SKW3086 GRK → DFW Jul 20, 02:01 UTCJul 20, 02:48 UTC47m
2026-07-19 SKW3086 GRK → DFW Jul 19, 23:45 UTCJul 20, 00:55 UTC1h 10m
2026-07-19 SKW3076 - Jul 19, 21:25 UTCJul 19, 22:25 UTC1h 0m
2026-07-19 SKW3076 LAX → STS Jul 19, 21:28 UTCJul 19, 22:15 UTC47m
2026-07-19 SKW3049 - Jul 19, 19:00 UTCJul 19, 20:05 UTC1h 5m
2026-07-19 SKW3114 - Jul 19, 16:40 UTCJul 19, 17:45 UTC1h 5m
2026-07-19 SKW3322 MFR → LAX Jul 19, 13:25 UTCJul 19, 15:05 UTC1h 40m
2026-07-19 SKW3206 SAN → MFR Jul 19, 03:25 UTCJul 19, 05:00 UTC1h 35m
2026-07-19 SKW3036 LAX → SFO Jul 19, 01:10 UTCJul 19, 02:25 UTC1h 15m

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 N173SY page for operator, model, and routing details .

Mode-S A125F9 frequently asked

What is Mode-S code A125F9?
A125F9 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N173SY.
Where is Mode-S A125F9 registered?
Mode-S code A125F9 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 A125F9 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 22:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A125F9, octal 50222771, decimal 10,561,017.
What flights does A125F9 operate?
Mode-S A125F9 has broadcast 20 distinct callsigns, including SKW3410, SKW3315, SKW3302, SKW3433, SKW3346.