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 22d ago
Flights observed
444
Distinct callsigns
20
Country
US
Last broadcast
22d ago

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
SKW864W SkyWest Airlines 4 2026-05-22
SKW3499 SkyWest Airlines 4 2026-06-13
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
SKW3293 SkyWest Airlines 4 2026-05-18
SKW3289 SkyWest Airlines 4 2026-06-08

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-06-21 SKW9790 - Jun 21, 15:34 UTCJun 21, 19:29 UTC3h 55m
2026-06-21 SKW3331 BOI → SAN Jun 21, 00:29 UTCJun 21, 02:15 UTC1h 45m
2026-06-20 SKW833K SAN → SMF Jun 20, 18:14 UTCJun 20, 19:29 UTC1h 15m
2026-06-20 SKW3015 SJC → LAX Jun 20, 16:00 UTCJun 20, 17:10 UTC1h 10m
2026-06-20 SKW3006 SEA → SFO Jun 20, 03:09 UTCJun 20, 04:24 UTC1h 15m
2026-06-20 SKW3337 - Jun 20, 00:29 UTCJun 20, 01:44 UTC1h 15m
2026-06-19 SKW3352 - Jun 19, 21:54 UTCJun 19, 23:09 UTC1h 15m
2026-06-19 SKW3426 LAX → SJC Jun 19, 19:19 UTCJun 19, 20:34 UTC1h 15m
2026-06-19 SKW3426 LAX → SJC Jun 19, 19:08 UTCJun 19, 20:31 UTC1h 23m
2026-06-19 SKW3463 - Jun 19, 16:55 UTCJun 19, 18:05 UTC1h 10m
2026-06-19 SKW3402 SFO → LAX Jun 19, 13:14 UTCJun 19, 14:09 UTC55m
2026-06-19 SKW3024 - Jun 19, 02:04 UTCJun 19, 03:29 UTC1h 25m
2026-06-18 SKW3098 - Jun 18, 23:50 UTCJun 19, 00:59 UTC1h 9m
2026-06-18 SKW3097 MRY → PHX Jun 18, 21:40 UTCJun 18, 22:30 UTC50m
2026-06-18 SKW3121 - Jun 18, 19:20 UTCJun 18, 20:30 UTC1h 10m
2026-06-18 SKW3110 SAN → RNO Jun 18, 16:55 UTCJun 18, 18:15 UTC1h 20m
2026-06-18 SKW3110 - Jun 18, 17:05 UTCJun 18, 18:10 UTC1h 5m
2026-06-18 SKW3018 DFW → LAW Jun 18, 13:50 UTCJun 18, 15:25 UTC1h 35m
2026-06-17 SKW3291 DFW → ASE Jun 17, 01:30 UTCJun 17, 02:55 UTC1h 25m
2026-06-16 SKW3202 LAX → PDX Jun 16, 23:45 UTCJun 17, 00:35 UTC50m
2026-06-16 SKW3075 STS → PSP Jun 16, 21:10 UTCJun 16, 22:50 UTC1h 40m
2026-06-16 SKW3025 DEN → SAN Jun 16, 18:09 UTCJun 16, 19:35 UTC1h 25m
2026-06-16 SKW3393 LAX → SFO Jun 16, 14:30 UTCJun 16, 16:10 UTC1h 40m
2026-06-16 SKW3393 LAX → SFO Jun 16, 14:19 UTCJun 16, 16:09 UTC1h 50m
2026-06-16 SKW3037 BNA → ORD Jun 16, 05:15 UTCJun 16, 06:15 UTC1h 0m
2026-06-16 SKW3232 SAN → SFO Jun 16, 03:00 UTCJun 16, 04:15 UTC1h 15m
2026-06-16 SKW3337 SAN → SFO Jun 16, 00:24 UTCJun 16, 01:40 UTC1h 15m
2026-06-15 SKW3212 MKE → ORD Jun 15, 21:50 UTCJun 15, 23:04 UTC1h 15m
2026-06-15 SKW3203 LAX → SFO Jun 15, 18:40 UTCJun 15, 20:20 UTC1h 40m
2026-06-15 SKW3203 LAX → SFO Jun 15, 18:27 UTCJun 15, 20:16 UTC1h 49m
2026-06-15 SKW3480 BZN → SAN Jun 15, 14:24 UTCJun 15, 16:09 UTC1h 45m
2026-06-15 SKW3480 BZN → SAN Jun 15, 14:23 UTCJun 15, 16:09 UTC1h 46m
2026-06-15 SKW3375 - Jun 15, 03:35 UTCJun 15, 04:50 UTC1h 15m
2026-06-15 SKW3070 SEA → PSC Jun 15, 00:45 UTCJun 15, 02:24 UTC1h 40m
2026-06-14 SKW3262 BFL → PHX Jun 14, 22:00 UTCJun 14, 22:50 UTC50m
2026-06-14 SKW3121 - Jun 14, 19:35 UTCJun 14, 20:45 UTC1h 10m
2026-06-14 SKW3121 RNO → PDX Jun 14, 19:30 UTCJun 14, 20:42 UTC1h 12m
2026-06-14 SKW3110 SAN → RNO Jun 14, 16:59 UTCJun 14, 18:12 UTC1h 13m
2026-06-14 SKW3110 - Jun 14, 17:00 UTCJun 14, 18:10 UTC1h 10m
2026-06-14 SKW3018 DFW → LAW Jun 14, 14:20 UTCJun 14, 15:50 UTC1h 30m
2026-06-14 SKW3291 DFW → ASE Jun 14, 01:20 UTCJun 14, 02:50 UTC1h 30m
2026-06-13 SKW3475 - Jun 13, 19:15 UTCJun 14, 00:00 UTC4h 45m
2026-06-13 SKW3499 LAX → SFO Jun 13, 16:30 UTCJun 13, 17:35 UTC1h 5m
2026-06-13 SKW3131 BOI → SJC Jun 13, 14:00 UTCJun 13, 15:25 UTC1h 25m
2026-06-13 SKW3413 SJC → BOI Jun 13, 03:45 UTCJun 13, 05:05 UTC1h 19m
2026-06-13 SKW3068 - Jun 13, 01:55 UTCJun 13, 02:55 UTC1h 0m
2026-06-12 SKW3429 SJC → SAN Jun 12, 23:35 UTCJun 13, 00:45 UTC1h 10m
2026-06-12 SKW3429 SJC → SAN Jun 12, 23:30 UTCJun 13, 00:40 UTC1h 10m
2026-06-12 SKW918J - Jun 12, 21:30 UTCJun 12, 22:30 UTC1h 0m
2026-06-12 SKW918J SAN → SJC Jun 12, 21:18 UTCJun 12, 22:29 UTC1h 11m

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 22d ago.
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.