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sensors Mode-S transponder

AAAC21

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N787SK · BOMBARDIER Regional Jet CRJ-700 · operated by SKYWEST AIRLINES INC

Hex
AAAC21
Octal
52526041
Decimal
11,185,185
Country
US
Tail
N787SK
Type
CRJ7
No current signal · last broadcast 3d ago
Flights observed
619
Distinct callsigns
20
Country
US
Last broadcast
3d ago

Last known position

Most recent position reported by Mode-S AAAC21.

Country allocation

The ICAO 24-bit address AAAC21 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
SKW5562 - 21 2026-07-10
SKW4683 - 21 2026-07-06
SKW5236 - 18 2026-07-10
SKW5724 - 16 2026-07-10
SKW5212 - 16 2026-07-10
SKW5688 - 15 2026-07-06
SKW5549 - 15 2026-07-10
SKW5946 - 14 2026-07-10
SKW5713 - 14 2026-07-09
SKW4661 - 12 2026-07-01
SKW5670 SkyWest Airlines 11 2026-06-16
SKW5480 - 11 2026-06-24
SKW5406 - 11 2026-07-09
SKW4697 SkyWest Airlines 10 2026-06-22
SKW4652 - 10 2026-06-16
SKW6046 - 9 2026-06-22
SKW5650 SkyWest Airlines 9 2026-05-21
SKW5225 SkyWest Airlines 9 2026-05-18
SKW4655 SkyWest Airlines 9 2026-05-16
SKW4628 - 9 2026-07-05

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-11 SKW6080 - Jul 11, 07:25 UTCJul 11, 07:50 UTC25m
2026-07-11 SKW6080 SFO → FAT Jul 11, 07:17 UTCJul 11, 07:45 UTC28m
2026-07-11 SKW5534 - Jul 11, 03:01 UTCJul 11, 04:25 UTC1h 25m
2026-07-11 SKW5534 RDM → SFO Jul 11, 03:00 UTCJul 11, 04:22 UTC1h 22m
2026-07-11 SKW5425 - Jul 11, 00:45 UTCJul 11, 01:55 UTC1h 10m
2026-07-10 SKW5946 - Jul 10, 22:20 UTCJul 10, 23:25 UTC1h 5m
2026-07-10 SKW5212 - Jul 10, 19:30 UTCJul 10, 20:30 UTC1h 0m
2026-07-10 SKW5562 - Jul 10, 17:25 UTCJul 10, 18:25 UTC1h 0m
2026-07-10 SKW5236 SFO → SNA Jul 10, 14:40 UTCJul 10, 15:50 UTC1h 10m
2026-07-10 SKW5549 RDD → SFO Jul 10, 12:25 UTCJul 10, 13:05 UTC40m
2026-07-10 SKW5724 - Jul 10, 06:20 UTCJul 10, 06:55 UTC35m
2026-07-10 SKW5724 SFO → RDD Jul 10, 06:32 UTCJul 10, 06:53 UTC21m
2026-07-10 SKW5534 - Jul 10, 03:20 UTCJul 10, 04:40 UTC1h 20m
2026-07-10 SKW5425 - Jul 10, 01:00 UTCJul 10, 02:10 UTC1h 10m
2026-07-09 SKW5946 - Jul 9, 22:30 UTCJul 9, 23:35 UTC1h 5m
2026-07-09 SKW5212 - Jul 9, 20:35 UTCJul 9, 21:30 UTC55m
2026-07-09 SKW5212 SFO → PSP Jul 9, 20:31 UTCJul 9, 21:27 UTC56m
2026-07-09 SKW5562 - Jul 9, 19:00 UTCJul 9, 19:10 UTC10m
2026-07-09 SKW5562 - Jul 9, 17:50 UTCJul 9, 19:10 UTC1h 20m
2026-07-09 SKW5562 SNA → SFO Jul 9, 17:49 UTCJul 9, 18:44 UTC55m
2026-07-09 SKW5236 SFO → SNA Jul 9, 14:51 UTCJul 9, 15:50 UTC59m
2026-07-09 SKW5549 RDD → SFO Jul 9, 12:30 UTCJul 9, 13:10 UTC40m
2026-07-09 SKW5724 SFO → RDD Jul 9, 06:00 UTCJul 9, 06:40 UTC40m
2026-07-09 SKW5724 SFO → RDD Jul 9, 06:01 UTCJul 9, 06:32 UTC31m
2026-07-09 SKW5713 - Jul 9, 04:30 UTCJul 9, 05:05 UTC35m
2026-07-09 SKW5713 SBP → SFO Jul 9, 04:27 UTCJul 9, 05:05 UTC38m
2026-07-09 SKW5406 - Jul 9, 02:00 UTCJul 9, 02:35 UTC35m
2026-07-08 SKW5946 - Jul 8, 22:20 UTCJul 8, 23:25 UTC1h 5m
2026-07-08 SKW5212 - Jul 8, 19:55 UTCJul 8, 20:45 UTC50m
2026-07-08 SKW5562 - Jul 8, 17:50 UTCJul 8, 18:50 UTC1h 0m
2026-07-08 SKW5236 - Jul 8, 14:35 UTCJul 8, 15:45 UTC1h 10m
2026-07-08 SKW5236 SFO → SNA Jul 8, 14:36 UTCJul 8, 15:41 UTC1h 5m
2026-07-08 SKW5549 RDD → SFO Jul 8, 12:32 UTCJul 8, 13:07 UTC35m
2026-07-08 SKW5549 RDD → SFO Jul 8, 12:25 UTCJul 8, 13:10 UTC45m
2026-07-08 SKW5724 - Jul 8, 06:20 UTCJul 8, 06:50 UTC30m
2026-07-08 SKW5713 - Jul 8, 03:45 UTCJul 8, 04:30 UTC45m
2026-07-08 SKW5406 SFO → SBP Jul 8, 01:50 UTCJul 8, 02:25 UTC35m
2026-07-07 SKW5946 - Jul 7, 22:45 UTCJul 7, 23:55 UTC1h 10m
2026-07-07 SKW5212 - Jul 7, 20:05 UTCJul 7, 21:00 UTC55m
2026-07-07 SKW5562 - Jul 7, 17:45 UTCJul 7, 18:50 UTC1h 5m
2026-07-07 SKW5562 SNA → SFO Jul 7, 17:58 UTCJul 7, 18:44 UTC46m
2026-07-07 SKW5236 - Jul 7, 15:45 UTCJul 7, 16:50 UTC1h 5m
2026-07-07 SKW5236 SFO → SNA Jul 7, 15:51 UTCJul 7, 16:41 UTC50m
2026-07-07 SKW5549 RDD → SFO Jul 7, 12:35 UTCJul 7, 13:20 UTC45m
2026-07-07 SKW5724 - Jul 7, 06:20 UTCJul 7, 06:55 UTC35m
2026-07-07 SKW5724 SFO → RDD Jul 7, 06:28 UTCJul 7, 06:54 UTC26m
2026-07-07 SKW5534 - Jul 7, 03:05 UTCJul 7, 04:30 UTC1h 25m
2026-07-07 SKW5425 - Jul 7, 00:35 UTCJul 7, 01:35 UTC1h 0m
2026-07-07 SKW5425 SFO → RDM Jul 7, 00:27 UTCJul 7, 01:35 UTC1h 8m
2026-07-06 SKW5946 - Jul 6, 22:05 UTCJul 6, 23:05 UTC1h 0m

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 N787SK page for operator, model, and routing details .

Mode-S AAAC21 frequently asked

What is Mode-S code AAAC21?
AAAC21 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N787SK.
Where is Mode-S AAAC21 registered?
Mode-S code AAAC21 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 AAAC21 broadcasting right now?
No active broadcast right now. Last signal was 3d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AAAC21, octal 52526041, decimal 11,185,185.
What flights does AAAC21 operate?
Mode-S AAAC21 has broadcast 20 distinct callsigns, including SKW5562, SKW4683, SKW5236, SKW5724, SKW5212.