Apparatus

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sensors Mode-S transponder

A4C0DB

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N405SY · EMBRAER ERJ-170-200 (long wing) · operated by SKYWEST AIRLINES INC

Hex
A4C0DB
Octal
51140333
Decimal
10,797,275
Country
US
Tail
N405SY
Type
E75L
No current signal · last broadcast Jul 26, 22:15 UTC
Flights observed
529
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:15 UTC

Last known position

Most recent position reported by Mode-S A4C0DB.

Country allocation

The ICAO 24-bit address A4C0DB 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
SKW3445 SkyWest Airlines 7 2026-05-24
SKW3400 SkyWest Airlines 7 2026-06-03
SKW3346 SkyWest Airlines 7 2026-05-08
SKW3426 SkyWest Airlines 6 2026-06-19
SKW3402 SkyWest Airlines 6 2026-06-19
SKW3375 - 5 2026-06-15
SKW3070 SkyWest Airlines 5 2026-06-15
SKW3068 - 5 2026-06-13
SKW3044 SkyWest Airlines 5 2026-07-22
SKW864W SkyWest Airlines 4 2026-05-22
SKW3499 SkyWest Airlines 4 2026-06-13
SKW3483 SkyWest Airlines 4 2026-07-25
SKW3480 SkyWest Airlines 4 2026-06-15
SKW3470 SkyWest Airlines 4 2026-04-30
SKW3463 - 4 2026-06-19
SKW3425 SkyWest Airlines 4 2026-05-10
SKW3362 SkyWest Airlines 4 2026-06-03
SKW3360 SkyWest Airlines 4 2026-06-04
SKW3337 - 4 2026-06-20
SKW3295 SkyWest Airlines 4 2026-06-08

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW3042 EUG → SEA Jul 26, 21:45 UTCJul 26, 22:10 UTC25m
2026-07-26 SKW3045 ORD → HPN Jul 26, 19:15 UTCJul 26, 20:30 UTC1h 15m
2026-07-26 SKW3055 LAX → LAS Jul 26, 16:35 UTCJul 26, 18:05 UTC1h 30m
2026-07-26 SKW3417 LAX → SFO Jul 26, 14:10 UTCJul 26, 14:45 UTC35m
2026-07-26 SKW3417 LAX → SFO Jul 26, 14:18 UTCJul 26, 15:04 UTC46m
2026-07-26 SKW3432 SAN → SFO Jul 26, 02:33 UTCJul 26, 03:19 UTC46m
2026-07-26 SKW3432 SAN → SFO Jul 26, 02:15 UTCJul 26, 03:20 UTC1h 5m
2026-07-26 SKW3231 SNA → SFO Jul 26, 00:15 UTCJul 26, 01:25 UTC1h 10m
2026-07-26 SKW3231 SNA → SFO Jul 26, 00:22 UTCJul 26, 01:24 UTC1h 2m
2026-07-25 SKW3483 PDX → SJC Jul 25, 22:05 UTCJul 25, 23:20 UTC1h 15m
2026-07-25 SKW3074 LAX → SFO Jul 25, 19:50 UTCJul 25, 20:15 UTC25m
2026-07-25 SKW3073 SAN → EUG Jul 25, 18:05 UTCJul 25, 18:35 UTC30m
2026-07-25 SKW3004 SJC → PHX Jul 25, 14:35 UTCJul 25, 16:00 UTC1h 25m
2026-07-25 SKW3291 DFW → ASE Jul 25, 01:25 UTCJul 25, 03:15 UTC1h 50m
2026-07-24 SKW3202 LAX → PDX Jul 24, 23:30 UTCJul 25, 00:20 UTC50m
2026-07-24 SKW3075 STS → PSP Jul 24, 21:00 UTCJul 24, 22:30 UTC1h 30m
2026-07-24 SKW3205 SAN → SFO Jul 24, 18:35 UTCJul 24, 19:40 UTC1h 5m
2026-07-24 SKW3315 LAX → SEA Jul 24, 13:40 UTCJul 24, 15:00 UTC1h 20m
2026-07-24 SKW3115 MCI → PHX Jul 24, 04:55 UTCJul 24, 06:15 UTC1h 20m
2026-07-24 SKW3030 SFO → BUR Jul 24, 01:55 UTCJul 24, 03:00 UTC1h 5m
2026-07-24 SKW3030 SFO → BUR Jul 24, 01:40 UTCJul 24, 03:05 UTC1h 25m
2026-07-23 SKW3029 PSP → SEA Jul 23, 23:40 UTCJul 24, 00:45 UTC1h 5m
2026-07-23 SKW3123 LTO → DFW Jul 23, 21:05 UTCJul 23, 22:40 UTC1h 35m
2026-07-23 SKW3123 LTO → DFW Jul 23, 21:00 UTCJul 23, 22:31 UTC1h 31m
2026-07-23 SKW3112 LAX → PDX Jul 23, 18:25 UTCJul 23, 20:00 UTC1h 35m
2026-07-23 SKW3112 LAX → PDX Jul 23, 18:11 UTCJul 23, 19:54 UTC1h 43m
2026-07-23 SKW3487 SAN → SMF Jul 23, 14:35 UTCJul 23, 16:00 UTC1h 25m
2026-07-23 SKW3343 SJC → SAN Jul 23, 04:00 UTCJul 23, 05:45 UTC1h 45m
2026-07-23 SKW3082 ACT → DFW Jul 23, 00:25 UTCJul 23, 02:05 UTC1h 40m
2026-07-22 SKW3083 PDX → STS Jul 22, 21:55 UTCJul 22, 22:45 UTC50m
2026-07-22 SKW3083 PDX → STS Jul 22, 21:36 UTCJul 22, 23:04 UTC1h 28m
2026-07-22 SKW3363 SFO → LAX Jul 22, 16:00 UTCJul 22, 20:20 UTC4h 20m
2026-07-22 SKW3448 - Jul 22, 13:10 UTCJul 22, 13:35 UTC25m
2026-07-22 SKW3044 PDX → SMF Jul 22, 02:45 UTCJul 22, 04:05 UTC1h 20m
2026-07-21 SKW3093 LAX → SFO Jul 21, 22:40 UTCJul 21, 23:45 UTC1h 5m
2026-07-21 SKW3223 - Jul 21, 18:35 UTCJul 21, 20:20 UTC1h 45m
2026-07-21 SKW3224 ORD → DTW Jul 21, 15:42 UTCJul 21, 16:52 UTC1h 10m
2026-07-21 SKW3224 ORD → DTW Jul 21, 15:25 UTCJul 21, 17:05 UTC1h 40m
2026-07-21 SKW3260 EUG → BUR Jul 21, 02:45 UTCJul 21, 04:30 UTC1h 45m
2026-07-21 SKW3199 SAN → SMF Jul 21, 01:00 UTCJul 21, 01:50 UTC50m
2026-07-20 SKW3408 PDX → FAT Jul 20, 22:50 UTCJul 20, 23:20 UTC30m
2026-07-20 SKW3408 PDX → FAT Jul 20, 22:46 UTCJul 20, 23:15 UTC29m
2026-07-20 SKW3204 SEA → PDX Jul 20, 21:10 UTCJul 20, 21:40 UTC30m
2026-07-20 SKW3078 LAX → SFO Jul 20, 19:15 UTCJul 20, 19:40 UTC25m
2026-07-20 SKW3078 LAX → SFO Jul 20, 19:19 UTCJul 20, 19:39 UTC20m
2026-07-20 SKW3090 BIS → DFW Jul 20, 17:40 UTCJul 20, 18:15 UTC35m
2026-07-20 SKW3219 - Jul 20, 14:15 UTCJul 20, 15:50 UTC1h 35m
2026-07-20 SKW3024 BNA → ORD Jul 20, 02:35 UTCJul 20, 04:05 UTC1h 30m
2026-07-20 SKW3098 STS → SNA Jul 20, 00:35 UTCJul 20, 01:40 UTC1h 5m
2026-07-19 SKW3097 MRY → PHX Jul 19, 21:50 UTCJul 19, 22:35 UTC45m

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 N405SY page for operator, model, and routing details .

Mode-S A4C0DB frequently asked

What is Mode-S code A4C0DB?
A4C0DB is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N405SY.
Where is Mode-S A4C0DB registered?
Mode-S code A4C0DB 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 A4C0DB 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 A4C0DB, octal 51140333, decimal 10,797,275.
What flights does A4C0DB operate?
Mode-S A4C0DB has broadcast 20 distinct callsigns, including SKW3445, SKW3400, SKW3346, SKW3426, SKW3402.