Apparatus

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sensors Mode-S transponder

A68E4C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N521SY · operated by SKYWEST AIRLINES INC

Hex
A68E4C
Octal
51507114
Decimal
10,915,404
Country
US
Tail
N521SY
Type
E75L
No current signal · last broadcast Jul 26, 22:05 UTC
Flights observed
553
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:05 UTC

Last known position

Most recent position reported by Mode-S A68E4C.

Country allocation

The ICAO 24-bit address A68E4C 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
SKW4975 SkyWest Airlines 25 2026-07-24
SKW4906 SkyWest Airlines 23 2026-07-24
SKW4925 - 18 2026-07-17
SKW6435 SkyWest Airlines 15 2026-07-25
SKW6253 - 14 2026-07-12
SKW4944 SkyWest Airlines 14 2026-07-20
SKW4915 - 12 2026-07-20
SKW6334 SkyWest Airlines 11 2026-07-25
SKW4983 - 11 2026-07-01
SKW4971 - 11 2026-07-15
SKW6240 SkyWest Airlines 10 2026-04-28
SKW6401 - 9 2026-07-20
SKW4982 - 9 2026-07-01
SKW6416 SkyWest Airlines 8 2026-07-23
SKW6366 - 8 2026-07-09
SKW6328 SkyWest Airlines 8 2026-07-25
SKW4911 SkyWest Airlines 8 2026-07-25
SKW6510 - 7 2026-07-15
SKW6428 SkyWest Airlines 7 2026-07-25
SKW6368 - 7 2026-07-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW6188 ORD → DTW Jul 26, 21:10 UTCJul 26, 22:05 UTC55m
2026-07-26 SKW6188 ORD → DTW Jul 26, 19:05 UTCJul 26, 20:10 UTC1h 5m
2026-07-26 SKW6336 PHX → ICT Jul 26, 16:35 UTCJul 26, 17:30 UTC55m
2026-07-26 SKW6336 PHX → ICT Jul 26, 14:25 UTCJul 26, 15:20 UTC55m
2026-07-26 SKW6346 ORD → BNA Jul 26, 04:15 UTCJul 26, 05:25 UTC1h 10m
2026-07-26 SKW6346 ORD → BNA Jul 26, 02:30 UTCJul 26, 03:30 UTC1h 0m
2026-07-25 SKW6270 LAX → SFO Jul 25, 23:00 UTCJul 26, 01:20 UTC2h 20m
2026-07-25 SKW6270 LAX → SFO Jul 25, 19:40 UTCJul 25, 21:15 UTC1h 35m
2026-07-25 SKW6428 PHX → SLC Jul 25, 17:15 UTCJul 25, 18:15 UTC1h 0m
2026-07-25 SKW4911 DFW → DRO Jul 25, 14:33 UTCJul 25, 16:14 UTC1h 41m
2026-07-25 SKW4911 DFW → DRO Jul 25, 14:45 UTCJul 25, 16:20 UTC1h 35m
2026-07-25 SKW6328 DRO → PHX Jul 25, 12:20 UTCJul 25, 13:10 UTC50m
2026-07-25 SKW6334 PHX → DRO Jul 25, 05:00 UTCJul 25, 05:45 UTC45m
2026-07-25 SKW6334 PHX → DRO Jul 25, 05:00 UTCJul 25, 05:59 UTC59m
2026-07-25 SKW6435 LAX → ABQ Jul 25, 02:15 UTCJul 25, 03:35 UTC1h 20m
2026-07-25 SKW6435 LAX → ABQ Jul 25, 02:13 UTCJul 25, 03:34 UTC1h 21m
2026-07-25 SKW6435 LAX → ABQ Jul 25, 00:10 UTCJul 25, 01:20 UTC1h 10m
2026-07-24 SKW4906 PHX → TUS Jul 24, 19:37 UTCJul 24, 21:49 UTC2h 12m
2026-07-24 SKW4906 PHX → TUS Jul 24, 15:50 UTCJul 24, 21:00 UTC5h 10m
2026-07-24 SKW4975 SJT → DFW Jul 24, 03:35 UTCJul 24, 04:25 UTC50m
2026-07-24 SKW4975 SJT → DFW Jul 24, 01:35 UTCJul 24, 02:25 UTC50m
2026-07-23 SKW6416 LAX → SFO Jul 23, 22:19 UTCJul 24, 00:16 UTC1h 57m
2026-07-23 SKW6416 LAX → SFO Jul 23, 19:35 UTCJul 23, 21:05 UTC1h 30m
2026-07-23 SKW4900 - Jul 23, 14:20 UTCJul 23, 14:45 UTC25m
2026-07-23 SKW4900 TUS → PHX Jul 23, 14:19 UTCJul 23, 14:44 UTC25m
2026-07-23 SKW6370 FAR → ORD Jul 23, 02:15 UTCJul 23, 02:50 UTC35m
2026-07-23 SKW6415 LCH → DFW Jul 23, 00:00 UTCJul 23, 01:15 UTC1h 15m
2026-07-22 SKW6415 LCH → DFW Jul 22, 22:00 UTCJul 22, 23:00 UTC1h 0m
2026-07-22 SKW6367 ORD → DTW Jul 22, 17:50 UTCJul 22, 18:15 UTC25m
2026-07-22 SKW6367 ORD → DTW Jul 22, 17:48 UTCJul 22, 18:13 UTC25m
2026-07-22 SKW6367 ORD → DTW Jul 22, 16:20 UTCJul 22, 16:50 UTC30m
2026-07-22 SKW6360 ORD → LEX Jul 22, 12:40 UTCJul 22, 14:55 UTC2h 15m
2026-07-22 SKW6292 ORD → ICT Jul 22, 04:00 UTCJul 22, 05:20 UTC1h 20m
2026-07-22 SKW4959 SJT → DFW Jul 22, 00:00 UTCJul 22, 02:45 UTC2h 45m
2026-07-21 SKW4959 SJT → DFW Jul 21, 20:45 UTCJul 21, 23:00 UTC2h 15m
2026-07-21 SKW4995 DFW → LAW Jul 21, 18:30 UTCJul 21, 19:30 UTC1h 0m
2026-07-21 SKW4995 DFW → LAW Jul 21, 16:25 UTCJul 21, 17:20 UTC55m
2026-07-21 SKW6360 - Jul 21, 12:40 UTCJul 21, 14:55 UTC2h 15m
2026-07-21 SKW6360 PSC → PHX Jul 21, 12:34 UTCJul 21, 14:52 UTC2h 18m
2026-07-21 SKW6292 ORD → ICT Jul 21, 05:10 UTCJul 21, 07:25 UTC2h 15m
2026-07-21 SKW4975 SJT → DFW Jul 21, 01:20 UTCJul 21, 02:20 UTC1h 0m
2026-07-20 SKW4975 SJT → DFW Jul 20, 22:50 UTCJul 20, 23:45 UTC55m
2026-07-20 SKW6416 LAX → SFO Jul 20, 16:35 UTCJul 20, 21:35 UTC5h 0m
2026-07-20 SKW6401 MFR → PHX Jul 20, 12:30 UTCJul 20, 14:35 UTC2h 5m
2026-07-20 SKW4915 PHX → MFR Jul 20, 04:25 UTCJul 20, 06:20 UTC1h 55m
2026-07-20 SKW4915 PHX → MFR Jul 20, 04:24 UTCJul 20, 06:19 UTC1h 55m
2026-07-20 SKW4944 PHX → PSC Jul 20, 02:05 UTCJul 20, 03:20 UTC1h 15m
2026-07-20 SKW4944 PHX → PSC Jul 20, 02:05 UTCJul 20, 03:16 UTC1h 11m
2026-07-20 SKW4944 PHX → PSC Jul 20, 00:15 UTCJul 20, 01:20 UTC1h 5m
2026-07-19 SKW4906 PHX → TUS Jul 19, 19:39 UTCJul 19, 22:12 UTC2h 33m

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 N521SY page for operator, model, and routing details .

Mode-S A68E4C frequently asked

What is Mode-S code A68E4C?
A68E4C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N521SY.
Where is Mode-S A68E4C registered?
Mode-S code A68E4C 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 A68E4C broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 22:05 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A68E4C, octal 51507114, decimal 10,915,404.
What flights does A68E4C operate?
Mode-S A68E4C has broadcast 20 distinct callsigns, including SKW4975, SKW4906, SKW4925, SKW6435, SKW6253.