Apparatus

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sensors Mode-S transponder

A18B41

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N199SY · EMBRAER ERJ-170-200 (long wing) · operated by SKYWEST AIRLINES INC

Hex
A18B41
Octal
50305501
Decimal
10,586,945
Country
US
Tail
N199SY
Type
E75L
No current signal · last broadcast Jul 26, 19:35 UTC
Flights observed
699
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 19:35 UTC

Last known position

Most recent position reported by Mode-S A18B41.

Country allocation

The ICAO 24-bit address A18B41 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
SKW3066 - 9 2026-07-07
SKW3105 SkyWest Airlines 8 2026-07-24
SKW3433 - 7 2026-07-08
SKW3404 SkyWest Airlines 7 2026-06-14
SKW3322 - 7 2026-07-17
SKW3033 SkyWest Airlines 7 2026-05-28
SKW3374 SkyWest Airlines 6 2026-06-17
SKW3288 - 6 2026-06-28
SKW3217 - 6 2026-07-19
SKW3118 - 6 2026-07-01
SKW3106 SkyWest Airlines 6 2026-07-09
SKW3079 - 6 2026-07-14
SKW3076 - 6 2026-06-28
SKW3073 SkyWest Airlines 6 2026-06-18
SKW3046 SkyWest Airlines 6 2026-06-07
SKW3009 SkyWest Airlines 6 2026-06-29
SKW3498 - 5 2026-06-22
SKW3445 SkyWest Airlines 5 2026-05-20
SKW3414 SkyWest Airlines 5 2026-05-14
SKW3413 - 5 2026-07-04

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW3047 DTW → ORD Jul 26, 18:10 UTCJul 26, 19:35 UTC1h 25m
2026-07-26 SKW3233 PHX → OKC Jul 26, 15:43 UTCJul 26, 16:45 UTC1h 2m
2026-07-26 SKW3233 PHX → OKC Jul 26, 15:30 UTCJul 26, 16:45 UTC1h 15m
2026-07-26 SKW3293 LAX → SJC Jul 26, 12:05 UTCJul 26, 14:25 UTC2h 20m
2026-07-26 SKW3292 ORD → BNA Jul 26, 01:13 UTCJul 26, 03:29 UTC2h 16m
2026-07-26 SKW3292 ORD → BNA Jul 26, 01:00 UTCJul 26, 03:30 UTC2h 30m
2026-07-25 SKW3056 IDA → SEA Jul 25, 21:45 UTCJul 25, 23:55 UTC2h 10m
2026-07-25 SKW3038 DFW → ACT Jul 25, 18:35 UTCJul 25, 20:20 UTC1h 45m
2026-07-25 SKW3499 LAX → SFO Jul 25, 16:25 UTCJul 25, 17:35 UTC1h 10m
2026-07-25 SKW3131 BOI → SJC Jul 25, 13:50 UTCJul 25, 15:30 UTC1h 40m
2026-07-25 SKW3375 SJC → PDX Jul 25, 02:40 UTCJul 25, 03:45 UTC1h 5m
2026-07-24 SKW3070 SEA → PSC Jul 24, 23:40 UTCJul 25, 01:40 UTC2h 0m
2026-07-24 SKW3262 BFL → PHX Jul 24, 22:05 UTCJul 24, 22:50 UTC45m
2026-07-24 SKW3062 STS → PSP Jul 24, 19:55 UTCJul 24, 20:20 UTC25m
2026-07-24 SKW3063 LAX → PDX Jul 24, 18:20 UTCJul 24, 18:50 UTC30m
2026-07-24 SKW3105 LAX → SFO Jul 24, 16:00 UTCJul 24, 16:50 UTC50m
2026-07-24 SKW3105 LAX → SFO Jul 24, 15:50 UTCJul 24, 16:42 UTC52m
2026-07-24 SKW849R SEA → BLI Jul 24, 06:25 UTCJul 24, 06:55 UTC30m
2026-07-24 SKW3044 PDX → SMF Jul 24, 02:40 UTCJul 24, 04:05 UTC1h 25m
2026-07-24 SKW3476 RDM → SFO Jul 24, 00:25 UTCJul 24, 01:30 UTC1h 5m
2026-07-23 SKW3369 PSP → SFO Jul 23, 17:45 UTCJul 23, 22:25 UTC4h 40m
2026-07-23 SKW3480 BZN → SAN Jul 23, 14:15 UTCJul 23, 16:05 UTC1h 50m
2026-07-23 SKW3215 SJD → LAS Jul 23, 02:30 UTCJul 23, 03:15 UTC45m
2026-07-23 SKW3052 SFO → LAX Jul 23, 00:55 UTCJul 23, 01:45 UTC50m
2026-07-22 SKW3421 SFO → LAX Jul 22, 22:50 UTCJul 22, 23:50 UTC1h 0m
2026-07-22 SKW3490 STS → SNA Jul 22, 20:10 UTCJul 22, 21:20 UTC1h 10m
2026-07-22 SKW3361 - Jul 22, 14:30 UTCJul 22, 17:15 UTC2h 45m
2026-07-22 SKW3361 TUS → SEA Jul 22, 14:28 UTCJul 22, 17:03 UTC2h 35m
2026-07-22 SKW3225 SEA → YVR Jul 22, 03:55 UTCJul 22, 05:25 UTC1h 30m
2026-07-22 SKW9796 LAX → STS Jul 22, 01:55 UTCJul 22, 02:20 UTC25m
2026-07-21 SKW3105 LAX → SFO Jul 21, 15:40 UTCJul 21, 16:30 UTC50m
2026-07-21 SKW849R SEA → BLI Jul 21, 06:20 UTCJul 21, 06:40 UTC20m
2026-07-21 SKW3044 PDX → SMF Jul 21, 03:40 UTCJul 21, 05:05 UTC1h 25m
2026-07-21 SKW3044 PDX → SMF Jul 21, 02:41 UTCJul 21, 04:56 UTC2h 15m
2026-07-21 SKW3476 RDM → SFO Jul 21, 00:20 UTCJul 21, 01:25 UTC1h 5m
2026-07-21 SKW3476 RDM → SFO Jul 21, 00:19 UTCJul 21, 01:24 UTC1h 5m
2026-07-20 SKW3349 - Jul 20, 19:05 UTCJul 20, 21:20 UTC2h 15m
2026-07-20 SKW3351 SAN → SJC Jul 20, 15:45 UTCJul 20, 17:50 UTC2h 5m
2026-07-20 SKW3351 SAN → SJC Jul 20, 15:50 UTCJul 20, 17:46 UTC1h 56m
2026-07-20 SKW3050 SEA → EUG Jul 20, 13:10 UTCJul 20, 14:20 UTC1h 10m
2026-07-20 SKW3115 MCI → PHX Jul 20, 05:00 UTCJul 20, 06:20 UTC1h 20m
2026-07-20 SKW3115 MCI → PHX Jul 20, 05:01 UTCJul 20, 06:20 UTC1h 19m
2026-07-20 SKW3280 PSP → SFO Jul 20, 01:55 UTCJul 20, 03:30 UTC1h 35m
2026-07-19 SKW3488 SJC → PDX Jul 19, 23:15 UTCJul 20, 00:50 UTC1h 35m
2026-07-19 SKW3028 PHX → SAN Jul 19, 20:26 UTCJul 19, 21:07 UTC41m
2026-07-19 SKW3028 PHX → SAN Jul 19, 20:20 UTCJul 19, 21:10 UTC50m
2026-07-19 SKW3023 SFO → SEA Jul 19, 18:20 UTCJul 19, 19:20 UTC1h 0m
2026-07-19 SKW3217 EUG → SAN Jul 19, 15:00 UTCJul 19, 17:20 UTC2h 20m
2026-07-19 SKW3323 LAX → PDX Jul 19, 02:25 UTCJul 19, 04:00 UTC1h 35m
2026-07-18 SKW3398 PDX → SBP Jul 18, 19:05 UTCJul 19, 00:45 UTC5h 40m

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 N199SY page for operator, model, and routing details .

Mode-S A18B41 frequently asked

What is Mode-S code A18B41?
A18B41 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N199SY.
Where is Mode-S A18B41 registered?
Mode-S code A18B41 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 A18B41 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 19:35 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A18B41, octal 50305501, decimal 10,586,945.
What flights does A18B41 operate?
Mode-S A18B41 has broadcast 20 distinct callsigns, including SKW3066, SKW3105, SKW3433, SKW3404, SKW3322.