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sensors Mode-S transponder

A3539D

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N313SY · EMBRAER ERJ-170-200 (long wing) · operated by SKYWEST AIRLINES INC

Hex
A3539D
Octal
50651635
Decimal
10,703,773
Country
US
Tail
N313SY
Type
E75L
No current signal · last broadcast 33m ago
Flights observed
636
Distinct callsigns
20
Country
US
Last broadcast
33m ago

Last known position

Most recent position reported by Mode-S A3539D.

Country allocation

The ICAO 24-bit address A3539D 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
SKW4101 - 10 2026-07-10
SKW3876 - 10 2026-07-11
SKW3620 - 9 2026-06-23
SKW3577 SkyWest Airlines 9 2026-06-27
SKW4091 SkyWest Airlines 8 2026-06-10
SKW3945 SkyWest Airlines 7 2026-06-28
SKW3822 SkyWest Airlines 7 2026-06-12
SKW4099 SkyWest Airlines 6 2026-06-07
SKW4043 SkyWest Airlines 6 2026-06-13
SKW4028 - 6 2026-07-09
SKW3974 SkyWest Airlines 6 2026-05-16
SKW3966 SkyWest Airlines 6 2026-06-13
SKW3952 - 6 2026-07-09
SKW3951 SkyWest Airlines 6 2026-06-11
SKW3759 - 6 2026-06-12
SKW3673 SkyWest Airlines 6 2026-06-01
SKW3669 - 6 2026-07-10
SKW4175 - 5 2026-07-11
SKW4134 - 5 2026-06-23
SKW4127 SkyWest Airlines 5 2026-06-01

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 SKW3914 - Jul 14, 10:15 UTCJul 14, 11:15 UTC1h 0m
2026-07-14 SKW3834 - Jul 14, 03:20 UTCJul 14, 04:10 UTC50m
2026-07-13 SKW3935 - Jul 13, 23:10 UTCJul 14, 00:05 UTC55m
2026-07-13 SKW3935 - Jul 13, 20:45 UTCJul 13, 21:45 UTC1h 0m
2026-07-13 SKW3536 - Jul 13, 17:05 UTCJul 13, 18:40 UTC1h 35m
2026-07-13 SKW3536 XNA → MSP Jul 13, 17:01 UTCJul 13, 18:40 UTC1h 39m
2026-07-13 SKW3536 MSP → XNA Jul 13, 14:30 UTCJul 13, 16:00 UTC1h 30m
2026-07-13 SKW3660 YWG → MSP Jul 13, 11:55 UTCJul 13, 13:00 UTC1h 5m
2026-07-13 SKW135K MSP → YWG Jul 13, 03:01 UTCJul 13, 04:05 UTC1h 5m
2026-07-13 SKW4462 MWC → MSP Jul 13, 00:15 UTCJul 13, 01:01 UTC45m
2026-07-12 SKW4462 - Jul 12, 22:10 UTCJul 12, 23:05 UTC55m
2026-07-12 SKW4032 - Jul 12, 20:10 UTCJul 12, 20:50 UTC40m
2026-07-12 SKW4032 MSN → MSP Jul 12, 20:11 UTCJul 12, 20:48 UTC37m
2026-07-12 SKW4032 - Jul 12, 18:35 UTCJul 12, 19:20 UTC45m
2026-07-12 SKW3813 AUS → MSP Jul 12, 14:55 UTCJul 12, 17:25 UTC2h 30m
2026-07-12 SKW4015 - Jul 12, 11:40 UTCJul 12, 13:45 UTC2h 5m
2026-07-12 SKW3731 AUS → IND Jul 12, 00:30 UTCJul 12, 02:45 UTC2h 15m
2026-07-12 SKW3731 AUS → IND Jul 12, 00:35 UTCJul 12, 02:44 UTC2h 9m
2026-07-11 SKW4016 MSY → AUS Jul 11, 22:25 UTCJul 11, 23:35 UTC1h 10m
2026-07-11 SKW141E AUS → MSY Jul 11, 19:45 UTCJul 11, 21:25 UTC1h 40m
2026-07-11 SKW3876 DEN → AUS Jul 11, 15:55 UTCJul 11, 17:40 UTC1h 45m
2026-07-11 SKW3876 AUS → DEN Jul 11, 12:40 UTCJul 11, 14:30 UTC1h 50m
2026-07-11 SKW4175 - Jul 11, 10:35 UTCJul 11, 11:20 UTC45m
2026-07-11 SKW4067 - Jul 11, 03:55 UTCJul 11, 04:35 UTC40m
2026-07-10 SKW4027 - Jul 10, 22:45 UTCJul 11, 01:05 UTC2h 20m
2026-07-10 SKW4027 AUS → IND Jul 10, 19:20 UTCJul 10, 21:25 UTC2h 5m
2026-07-10 SKW4101 - Jul 10, 15:55 UTCJul 10, 18:05 UTC2h 10m
2026-07-10 SKW4101 AUS → IND Jul 10, 13:00 UTCJul 10, 15:10 UTC2h 10m
2026-07-10 SKW3669 DEN → AUS Jul 10, 02:00 UTCJul 10, 03:50 UTC1h 50m
2026-07-09 SKW3669 AUS → DEN Jul 9, 22:00 UTCJul 10, 00:25 UTC2h 25m
2026-07-09 SKW4028 - Jul 9, 18:15 UTCJul 9, 20:40 UTC2h 25m
2026-07-09 SKW4028 CMH → AUS Jul 9, 18:12 UTCJul 9, 20:35 UTC2h 23m
2026-07-09 SKW4028 AUS → CMH Jul 9, 14:40 UTCJul 9, 17:10 UTC2h 30m
2026-07-09 SKW4088 - Jul 9, 12:05 UTCJul 9, 13:25 UTC1h 20m
2026-07-09 SKW3952 - Jul 9, 01:05 UTCJul 9, 02:35 UTC1h 30m
2026-07-09 SKW3952 AUS → MEM Jul 9, 01:06 UTCJul 9, 02:21 UTC1h 15m
2026-07-08 SKW4053 - Jul 8, 22:10 UTCJul 8, 23:00 UTC50m
2026-07-08 SKW4053 MFE → AUS Jul 8, 22:08 UTCJul 8, 22:55 UTC47m
2026-07-08 SKW4053 - Jul 8, 20:10 UTCJul 8, 20:55 UTC45m
2026-07-08 SKW3960 - Jul 8, 16:35 UTCJul 8, 18:25 UTC1h 50m
2026-07-08 SKW3960 AUS → BNA Jul 8, 13:35 UTCJul 8, 15:25 UTC1h 50m
2026-07-08 SKW3669 DEN → AUS Jul 8, 01:55 UTCJul 8, 03:35 UTC1h 40m
2026-07-07 SKW3669 AUS → DEN Jul 7, 22:00 UTCJul 8, 00:10 UTC2h 10m
2026-07-07 SKW3955 SLC → AUS Jul 7, 16:50 UTCJul 7, 19:15 UTC2h 25m
2026-07-07 SKW4152 MEM → LGA Jul 7, 14:00 UTCJul 7, 15:20 UTC1h 20m
2026-07-07 SKW3729 SLC → ABQ Jul 7, 02:55 UTCJul 7, 04:20 UTC1h 25m
2026-07-07 SKW3903 OAK → SLC Jul 7, 00:10 UTCJul 7, 01:40 UTC1h 30m
2026-07-06 SKW3903 SLC → OAK Jul 6, 21:35 UTCJul 6, 23:05 UTC1h 30m
2026-07-06 SKW3815 - Jul 6, 17:40 UTCJul 6, 19:45 UTC2h 5m
2026-07-06 SKW3815 OMA → SLC Jul 6, 17:44 UTCJul 6, 19:41 UTC1h 57m

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 N313SY page for operator, model, and routing details .

Mode-S A3539D frequently asked

What is Mode-S code A3539D?
A3539D is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N313SY.
Where is Mode-S A3539D registered?
Mode-S code A3539D 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 A3539D broadcasting right now?
No active broadcast right now. Last signal was 33m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A3539D, octal 50651635, decimal 10,703,773.
What flights does A3539D operate?
Mode-S A3539D has broadcast 20 distinct callsigns, including SKW4101, SKW3876, SKW3620, SKW3577, SKW4091.