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sensors Mode-S transponder

A05559

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N120SY · EMBRAER ERJ-170-200 (long wing) · operated by SKYWEST AIRLINES INC

Hex
A05559
Octal
50052531
Decimal
10,507,609
Country
US
Tail
N120SY
Type
E75L
No current signal · last broadcast Jul 26, 21:55 UTC
Flights observed
542
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:55 UTC

Last known position

Most recent position reported by Mode-S A05559.

Country allocation

The ICAO 24-bit address A05559 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
SKW5932 SkyWest Airlines 8 2026-06-03
SKW6001 - 6 2026-07-12
SKW5476 - 6 2026-07-20
SKW5994 SkyWest Airlines 5 2026-06-10
SKW5991 - 5 2026-07-20
SKW5911 - 5 2026-07-09
SKW5616 - 5 2026-07-14
SKW5364 SkyWest Airlines 5 2026-06-03
SKW5243 - 5 2026-07-12
SKW5242 SkyWest Airlines 5 2026-07-24
SKW6014 SkyWest Airlines 4 2026-07-25
SKW5886 - 4 2026-07-15
SKW5876 - 4 2026-07-23
SKW5780 SkyWest Airlines 4 2026-04-25
SKW5765 SkyWest Airlines 4 2026-06-10
SKW5717 - 4 2026-07-13
SKW5673 - 4 2026-07-14
SKW5623 SkyWest Airlines 4 2026-07-25
SKW5596 SkyWest Airlines 4 2026-07-24
SKW5570 SkyWest Airlines 4 2026-06-03

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW346W ORD → JAX Jul 26, 20:10 UTCJul 26, 21:55 UTC1h 45m
2026-07-26 SKW5517 LAX → MFR Jul 26, 17:15 UTCJul 26, 17:45 UTC30m
2026-07-26 SKW5668 ORD → DCA Jul 26, 14:00 UTCJul 26, 14:30 UTC30m
2026-07-26 SKW527C BGR → ORD Jul 26, 10:16 UTCJul 26, 12:25 UTC2h 9m
2026-07-26 SKW527C BGR → ORD Jul 26, 10:10 UTCJul 26, 12:35 UTC2h 25m
2026-07-25 SKWW5681 - Jul 25, 23:45 UTCJul 26, 01:50 UTC2h 5m
2026-07-25 SKW5623 ORD → BHM Jul 25, 18:15 UTCJul 25, 21:20 UTC3h 5m
2026-07-25 SKW6014 SFO → GEG Jul 25, 15:30 UTCJul 25, 17:00 UTC1h 30m
2026-07-25 SKW5313 ACV → SFO Jul 25, 13:20 UTCJul 25, 14:05 UTC45m
2026-07-25 SKW5313 ACV → SFO Jul 25, 13:21 UTCJul 25, 13:57 UTC36m
2026-07-25 SKW5626 SFO → BUR Jul 25, 05:00 UTCJul 25, 05:30 UTC30m
2026-07-25 SKW5624 SFO → ABQ Jul 25, 01:55 UTCJul 25, 02:55 UTC1h 0m
2026-07-24 SKW5613 SFO → MRY Jul 24, 23:30 UTCJul 25, 00:35 UTC1h 5m
2026-07-24 SKW4628 DEN → CVG Jul 24, 20:10 UTCJul 24, 22:25 UTC2h 15m
2026-07-24 SKW5401 ORD → FWA Jul 24, 16:55 UTCJul 24, 18:55 UTC2h 0m
2026-07-24 SKW5596 MTY → SFO Jul 24, 11:50 UTCJul 24, 14:50 UTC3h 0m
2026-07-24 SKW5242 ORD → ROC Jul 24, 00:35 UTCJul 24, 01:55 UTC1h 20m
2026-07-24 SKW5242 ORD → ROC Jul 24, 00:07 UTCJul 24, 01:48 UTC1h 41m
2026-07-23 SKW5580 ORD → COS Jul 23, 20:10 UTCJul 23, 21:55 UTC1h 45m
2026-07-23 SKW5580 ORD → COS Jul 23, 20:12 UTCJul 23, 21:57 UTC1h 45m
2026-07-23 SKW5397 TUL → IAH Jul 23, 17:15 UTCJul 23, 19:05 UTC1h 50m
2026-07-23 SKW5397 TUL → IAH Jul 23, 17:22 UTCJul 23, 18:54 UTC1h 32m
2026-07-23 SKW5876 - Jul 23, 13:05 UTCJul 23, 15:10 UTC2h 5m
2026-07-23 SKW5876 OAX → IAH Jul 23, 12:46 UTCJul 23, 15:06 UTC2h 20m
2026-07-22 SKW5875 MSY → ORD Jul 22, 22:05 UTCJul 22, 23:55 UTC1h 50m
2026-07-22 SKW5531 - Jul 22, 18:55 UTCJul 22, 20:00 UTC1h 5m
2026-07-22 SKW5324 ASE → ORD Jul 22, 16:30 UTCJul 22, 17:55 UTC1h 25m
2026-07-22 SKW4751 DEN → DIK Jul 22, 11:35 UTCJul 22, 12:35 UTC1h 0m
2026-07-21 SKW5291 DEN → MSP Jul 21, 22:00 UTCJul 21, 23:00 UTC1h 0m
2026-07-21 SKW5291 DEN → MSP Jul 21, 21:54 UTCJul 21, 23:13 UTC1h 19m
2026-07-21 SKW5531 - Jul 21, 18:55 UTCJul 21, 20:00 UTC1h 5m
2026-07-21 SKW5324 ASE → ORD Jul 21, 16:30 UTCJul 21, 17:55 UTC1h 25m
2026-07-21 SKW5969 SFO → SEA Jul 21, 11:05 UTCJul 21, 12:35 UTC1h 30m
2026-07-21 SKW5269 DEN → SJC Jul 21, 03:00 UTCJul 21, 04:30 UTC1h 30m
2026-07-20 SKW5380 - Jul 20, 23:05 UTCJul 21, 01:05 UTC1h 59m
2026-07-20 SKW5380 MSN → DEN Jul 20, 23:14 UTCJul 21, 00:48 UTC1h 34m
2026-07-20 SKW4805 - Jul 20, 20:35 UTCJul 20, 22:20 UTC1h 45m
2026-07-20 SKW5991 - Jul 20, 18:45 UTCJul 20, 19:20 UTC35m
2026-07-20 SKW5991 FCA → DEN Jul 20, 17:04 UTCJul 20, 19:21 UTC2h 17m
2026-07-20 SKW5476 - Jul 20, 14:10 UTCJul 20, 15:50 UTC1h 40m
2026-07-20 SKW5667 ORD → MSN Jul 20, 11:15 UTCJul 20, 12:30 UTC1h 15m
2026-07-20 SKW4712 ORD → CHA Jul 20, 03:15 UTCJul 20, 04:30 UTC1h 15m
2026-07-19 SKW5632 SNA → SFO Jul 19, 23:35 UTCJul 20, 01:10 UTC1h 35m
2026-07-19 SKW5632 SNA → SFO Jul 19, 20:25 UTCJul 20, 01:15 UTC4h 50m
2026-07-19 SKW5991 - Jul 19, 18:00 UTCJul 19, 18:35 UTC35m
2026-07-19 SKW5476 - Jul 19, 14:05 UTCJul 19, 14:15 UTC10m
2026-07-19 SKW5476 DEN → FCA Jul 19, 13:59 UTCJul 19, 15:57 UTC1h 58m
2026-07-19 SKW5667 ORD → MSN Jul 19, 11:20 UTCJul 19, 12:40 UTC1h 20m
2026-07-19 SKW4712 ORD → CHA Jul 19, 03:40 UTCJul 19, 04:55 UTC1h 15m
2026-07-18 SKW5429 - Jul 18, 21:55 UTCJul 18, 23:50 UTC1h 55m

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 N120SY page for operator, model, and routing details .

Mode-S A05559 frequently asked

What is Mode-S code A05559?
A05559 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N120SY.
Where is Mode-S A05559 registered?
Mode-S code A05559 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 A05559 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:55 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A05559, octal 50052531, decimal 10,507,609.
What flights does A05559 operate?
Mode-S A05559 has broadcast 20 distinct callsigns, including SKW5932, SKW6001, SKW5476, SKW5994, SKW5991.