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sensors Mode-S transponder

A9D420

ICAO 24-bit transponder address · allocated to United States

Hex
A9D420
Octal
52352040
Decimal
11,129,888
Country
US
No current signal · last broadcast Jul 26, 21:00 UTC
Flights observed
65
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:00 UTC

Last known position

Most recent position reported by Mode-S A9D420.

Country allocation

The ICAO 24-bit address A9D420 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
SKW6085 - 4 2026-07-18
SKW5608 SkyWest Airlines 4 2026-07-26
SKW5306 SkyWest Airlines 4 2026-07-24
SKW5884 SkyWest Airlines 3 2026-07-26
SKW5793 SkyWest Airlines 3 2026-07-23
SKW5791 SkyWest Airlines 3 2026-07-24
SKW5421 SkyWest Airlines 3 2026-07-20
SKW5404 SkyWest Airlines 3 2026-07-26
SKW5374 SkyWest Airlines 3 2026-07-23
SKW4658 SkyWest Airlines 3 2026-07-26
SKW1001 - 3 2026-07-10
SKW1000 - 3 2026-07-09
SKW786H SkyWest Airlines 2 2026-07-26
SKW5818 SkyWest Airlines 2 2026-07-22
SKW5671 SkyWest Airlines 2 2026-07-23
SKW5481 SkyWest Airlines 2 2026-07-22
SKW5428 SkyWest Airlines 2 2026-07-24
SKW4693 SkyWest Airlines 2 2026-07-25
SKW4675 SkyWest Airlines 2 2026-07-24
SKW799Z SkyWest Airlines 1 2026-07-23

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW4658 ASE → SFO Jul 26, 19:55 UTCJul 26, 20:55 UTC1h 0m
2026-07-26 SKW786H DEN → CPR Jul 26, 17:45 UTCJul 26, 18:25 UTC40m
2026-07-26 SKW5884 DEN → FAT Jul 26, 15:25 UTCJul 26, 16:05 UTC40m
2026-07-26 SKW5608 OMA → ORD Jul 26, 03:27 UTCJul 26, 04:08 UTC41m
2026-07-26 SKW5608 OMA → ORD Jul 26, 03:20 UTCJul 26, 03:50 UTC30m
2026-07-26 SKW5404 SGF → ORD Jul 26, 00:00 UTCJul 26, 01:30 UTC1h 30m
2026-07-25 SKW4693 LAX → RDM Jul 25, 21:20 UTCJul 25, 22:45 UTC1h 25m
2026-07-25 SKW4658 ASE → SFO Jul 25, 19:35 UTCJul 25, 20:20 UTC45m
2026-07-25 SKW4658 ASE → SFO Jul 25, 19:44 UTCJul 25, 20:16 UTC32m
2026-07-25 SKW786H DEN → CPR Jul 25, 17:50 UTCJul 25, 18:30 UTC40m
2026-07-25 SKW5884 DEN → FAT Jul 25, 15:45 UTCJul 25, 16:15 UTC30m
2026-07-25 SKW5884 DEN → FAT Jul 25, 15:16 UTCJul 25, 16:07 UTC51m
2026-07-25 SKW5608 OMA → ORD Jul 25, 01:50 UTCJul 25, 02:25 UTC35m
2026-07-25 SKW5608 OMA → ORD Jul 25, 01:34 UTCJul 25, 02:37 UTC1h 3m
2026-07-24 SKW5404 SGF → ORD Jul 24, 22:15 UTCJul 24, 23:50 UTC1h 35m
2026-07-24 SKW5404 SGF → ORD Jul 24, 22:16 UTCJul 24, 23:45 UTC1h 29m
2026-07-24 SKW4693 LAX → RDM Jul 24, 19:40 UTCJul 24, 21:00 UTC1h 20m
2026-07-24 SKW4675 SFO → PSP Jul 24, 18:05 UTCJul 24, 18:25 UTC20m
2026-07-24 SKW5306 SFO → ACV Jul 24, 16:35 UTCJul 24, 17:00 UTC25m
2026-07-24 SKW5306 SFO → ACV Jul 24, 16:28 UTCJul 24, 16:52 UTC24m
2026-07-24 SKW5791 LBB → DEN Jul 24, 13:10 UTCJul 24, 14:20 UTC1h 10m
2026-07-24 SKW5428 SFO → SBP Jul 24, 02:30 UTCJul 24, 03:50 UTC1h 20m
2026-07-23 SKW5947 ASE → LAX Jul 23, 21:00 UTCJul 24, 00:50 UTC3h 50m
2026-07-23 SKW5793 SJC → DEN Jul 23, 16:55 UTCJul 23, 17:55 UTC1h 0m
2026-07-23 SKW5374 SGF → IAH Jul 23, 14:30 UTCJul 23, 15:00 UTC30m
2026-07-23 SKW4641 ORD → FNT Jul 23, 11:25 UTCJul 23, 12:10 UTC45m
2026-07-23 SKW486V DEN → IDA Jul 23, 04:15 UTCJul 23, 04:40 UTC25m
2026-07-23 SKW5671 ORD → ROA Jul 23, 02:20 UTCJul 23, 03:05 UTC45m
2026-07-23 SKW5671 ORD → ROA Jul 23, 02:17 UTCJul 23, 02:58 UTC41m
2026-07-23 SKW799Z DEN → DIK Jul 23, 00:05 UTCJul 23, 00:40 UTC35m
2026-07-22 SKW5541 - Jul 22, 19:05 UTCJul 22, 20:40 UTC1h 35m
2026-07-22 SKW5481 SMF → SFO Jul 22, 16:40 UTCJul 22, 18:10 UTC1h 30m
2026-07-22 SKW5818 CPR → DEN Jul 22, 14:25 UTCJul 22, 15:10 UTC45m
2026-07-22 SKW5818 CPR → DEN Jul 22, 14:01 UTCJul 22, 15:10 UTC1h 9m
2026-07-22 SKW5802 MSN → ORD Jul 22, 01:40 UTCJul 22, 02:25 UTC45m
2026-07-21 SKW5848 FSD → DEN Jul 21, 22:30 UTCJul 21, 23:45 UTC1h 15m
2026-07-21 SKW5378 DEN → FSD Jul 21, 20:00 UTCJul 21, 21:25 UTC1h 25m
2026-07-21 SKW4675 SFO → PSP Jul 21, 17:45 UTCJul 21, 18:10 UTC25m
2026-07-21 SKW5306 SFO → ACV Jul 21, 16:05 UTCJul 21, 16:30 UTC25m
2026-07-21 SKW5306 SFO → ACV Jul 21, 16:06 UTCJul 21, 16:26 UTC20m
2026-07-21 SKW5791 LBB → DEN Jul 21, 13:10 UTCJul 21, 14:15 UTC1h 5m
2026-07-21 SKW5428 SFO → SBP Jul 21, 01:45 UTCJul 21, 02:50 UTC1h 5m
2026-07-20 SKW5989 - Jul 20, 22:35 UTCJul 20, 23:45 UTC1h 10m
2026-07-20 SKW5421 ORD → LIT Jul 20, 20:35 UTCJul 20, 21:35 UTC1h 0m
2026-07-20 SKW5421 ORD → LIT Jul 20, 20:15 UTCJul 20, 21:34 UTC1h 19m
2026-07-20 SKW5793 SJC → DEN Jul 20, 17:55 UTCJul 20, 18:45 UTC50m
2026-07-20 SKW5793 SJC → DEN Jul 20, 17:28 UTCJul 20, 18:43 UTC1h 15m
2026-07-20 SKW5374 SGF → IAH Jul 20, 14:27 UTCJul 20, 15:27 UTC1h 0m
2026-07-20 SKW5374 SGF → IAH Jul 20, 14:20 UTCJul 20, 15:20 UTC1h 0m
2026-07-20 SKW5291 DEN → MSP Jul 20, 12:20 UTCJul 20, 12:50 UTC30m

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.

Mode-S A9D420 frequently asked

What is Mode-S code A9D420?
A9D420 is an ICAO 24-bit transponder address. Allocated to United States.
Where is Mode-S A9D420 registered?
Mode-S code A9D420 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 A9D420 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:00 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A9D420, octal 52352040, decimal 11,129,888.
What flights does A9D420 operate?
Mode-S A9D420 has broadcast 20 distinct callsigns, including SKW6085, SKW5608, SKW5306, SKW5884, SKW5793.