sensors Mode-S transponder

A85D1B

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N638SY · operated by SKYWEST AIRLINES INC

Hex
A85D1B
Octal
52056433
Decimal
11,033,883
Country
US
Tail
N638SY
No current signal · last broadcast 20m ago
Flights observed
309
Distinct callsigns
20
Country
US
Last broadcast
20m ago

Last known position

Most recent position reported by Mode-S A85D1B.

Country allocation

The ICAO 24-bit address A85D1B 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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 SKW5375 ORD → MSN May 29, 22:45 UTCMay 30, 00:25 UTC1h 40m
2026-05-29 SKW5993 MSN → DEN May 29, 13:04 UTCMay 29, 14:39 UTC1h 35m
2026-05-29 SKW5993 MSN → DEN May 29, 13:05 UTCMay 29, 14:40 UTC1h 35m
2026-05-29 SKW4754 SNA → SFO May 29, 10:20 UTCMay 29, 11:15 UTC55m
2026-05-28 SKW769W ORD → DTW May 28, 23:30 UTCMay 29, 00:15 UTC45m
2026-05-28 SKW5956 ASE → ORD May 28, 18:55 UTCMay 28, 21:20 UTC2h 25m
2026-05-28 SKW5814 RNO → SFO May 28, 15:05 UTCMay 28, 16:55 UTC1h 50m
2026-05-28 SKW5259 ICT → ORD May 28, 13:15 UTCMay 28, 13:50 UTC35m
2026-05-28 SKW5259 ICT → ORD May 28, 12:47 UTCMay 28, 13:47 UTC1h 0m
2026-05-28 SKW376Z DEN → SHV May 28, 01:05 UTCMay 28, 02:55 UTC1h 50m
2026-05-27 SKW5749 PIT → ORD May 27, 21:50 UTCMay 27, 22:20 UTC30m
2026-05-27 SKW5749 PIT → ORD May 27, 21:52 UTCMay 27, 22:17 UTC25m
2026-05-27 SKW713L DEN → GUC May 27, 19:50 UTCMay 27, 20:20 UTC30m
2026-05-27 SKW4804 DTW → ORD May 27, 17:25 UTCMay 27, 18:30 UTC1h 5m
2026-05-27 SKW4809 ORD → ICT May 27, 14:20 UTCMay 27, 15:40 UTC1h 20m
2026-05-27 SKW4667 BHM → ORD May 27, 10:10 UTCMay 27, 12:55 UTC2h 45m
2026-05-26 SKW5681 SFO → SBP May 26, 23:54 UTCMay 27, 00:44 UTC50m
2026-05-26 SKW5375 ORD → MSN May 26, 17:09 UTCMay 26, 18:55 UTC1h 45m
2026-05-26 SKW5993 MSN → DEN May 26, 13:34 UTCMay 26, 15:09 UTC1h 35m
2026-05-26 SKW5993 MSN → DEN May 26, 13:04 UTCMay 26, 15:09 UTC2h 5m
2026-05-26 SKW5690 SGF → IAH May 26, 10:20 UTCMay 26, 10:54 UTC35m
2026-05-25 SKW5918 SFO → BUR May 25, 23:30 UTCMay 25, 23:54 UTC25m
2026-05-25 SKW5918 SFO → BUR May 25, 23:26 UTCMay 25, 23:58 UTC32m
2026-05-25 SKW6000 HPN → ORD May 25, 19:50 UTCMay 25, 21:19 UTC1h 30m
2026-05-25 SKW5413 DEN → MRY May 25, 17:45 UTCMay 25, 18:55 UTC1h 10m
2026-05-25 SKW5413 DEN → MRY May 25, 17:29 UTCMay 25, 18:44 UTC1h 15m
2026-05-25 SKW5300 LCH → IAH May 25, 13:35 UTCMay 25, 15:35 UTC2h 0m
2026-05-24 SKW5694 GRB → ORD May 24, 23:00 UTCMay 24, 23:46 UTC46m
2026-05-24 SKW5641 SJC → DEN May 24, 19:45 UTCMay 24, 21:10 UTC1h 25m
2026-05-24 SKW5520 OKC → IAH May 24, 15:50 UTCMay 24, 17:40 UTC1h 50m
2026-05-24 SKW5529 LAX → RDD May 24, 01:45 UTCMay 24, 03:45 UTC2h 0m
2026-05-24 SKW5529 LAX → RDD May 24, 01:34 UTCMay 24, 03:41 UTC2h 7m
2026-05-23 SKW5914 LNK → ORD May 23, 22:25 UTCMay 23, 22:45 UTC20m
2026-05-23 SKW5914 LNK → ORD May 23, 22:25 UTCMay 23, 23:44 UTC1h 19m
2026-05-23 SKW5311 ORD → DCA May 23, 20:00 UTCMay 23, 21:15 UTC1h 15m
2026-05-23 SKW5787 FAT → DEN May 23, 16:20 UTCMay 23, 18:15 UTC1h 56m
2026-05-23 SKW5787 FAT → DEN May 23, 16:18 UTCMay 23, 18:13 UTC1h 55m
2026-05-23 SKW5329 ACV → LAX May 23, 04:50 UTCMay 23, 05:20 UTC30m
2026-05-23 SKW5940 ORD → MCI May 23, 01:35 UTCMay 23, 03:10 UTC1h 34m
2026-05-23 SKW5940 ORD → MCI May 23, 01:32 UTCMay 23, 03:04 UTC1h 32m
2026-05-22 SKW5775 DEN → ASE May 22, 23:35 UTCMay 22, 23:55 UTC20m
2026-05-22 SKW5776 JAC → SFO May 22, 21:50 UTCMay 22, 22:15 UTC25m
2026-05-22 SKW5771 RDM → DEN May 22, 20:00 UTCMay 22, 20:20 UTC20m
2026-05-22 SKW5772 ASE → DEN May 22, 18:00 UTCMay 22, 18:25 UTC25m
2026-05-22 SKW5782 DEN → ASE May 22, 16:15 UTCMay 22, 16:30 UTC15m
2026-05-22 SKW5782 DEN → ASE May 22, 16:11 UTCMay 22, 16:42 UTC31m
2026-05-22 SKW5766 ASE → DEN May 22, 14:00 UTCMay 22, 14:25 UTC25m
2026-05-21 SKW5917 SFO → SEA May 21, 23:25 UTCMay 22, 01:25 UTC2h 0m
2026-05-21 SKW5637 ORD → MDT May 21, 19:00 UTCMay 21, 20:30 UTC1h 30m
2026-05-21 SKW5315 ASE → ORD May 21, 16:40 UTCMay 21, 18:00 UTC1h 20m

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 N638SY page for operator, model, and routing details .

Mode-S A85D1B frequently asked

What is Mode-S code A85D1B?
A85D1B is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N638SY.
Where is Mode-S A85D1B registered?
Mode-S code A85D1B 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 A85D1B broadcasting right now?
No active broadcast right now. Last signal was 20m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A85D1B, octal 52056433, decimal 11,033,883.
What flights does A85D1B operate?
Mode-S A85D1B has broadcast 20 distinct callsigns, including SKW5993, SKW5445, SKW4742, SKW5851, SKW5782.