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sensors Mode-S transponder

A651E1

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N506SY · EMBRAER ERJ-170-200 (long wing) · operated by SKYWEST AIRLINES INC

Hex
A651E1
Octal
51450741
Decimal
10,899,937
Country
US
Tail
N506SY
Type
E75L
No current signal · last broadcast 2h ago
Flights observed
579
Distinct callsigns
20
Country
US
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S A651E1.

Country allocation

The ICAO 24-bit address A651E1 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
SKW6409 - 26 2026-07-13
SKW5005 - 15 2026-07-08
SKW6366 - 13 2026-07-12
SKW6353 SkyWest Airlines 13 2026-05-08
SKW6272 - 12 2026-07-01
SKW4991 SkyWest Airlines 12 2026-05-21
SKW6482 - 11 2026-07-11
SKW6307 - 11 2026-07-03
SKW4895 - 11 2026-07-12
SKW6185 - 10 2026-07-02
SKW4898 - 10 2026-07-14
SKW6428 - 9 2026-07-05
SKW6415 SkyWest Airlines 9 2026-06-15
SKW6381 - 9 2026-06-19
SKW6330 - 9 2026-07-07
SKW6187 - 9 2026-07-11
SKW4979 - 9 2026-07-01
SKW6371 SkyWest Airlines 8 2026-04-30
SKW6346 - 8 2026-07-04
SKW6326 SkyWest Airlines 8 2026-05-14

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 SKW4898 - Jul 14, 00:30 UTCJul 14, 03:15 UTC2h 45m
2026-07-13 SKW6409 - Jul 13, 20:50 UTCJul 13, 23:25 UTC2h 35m
2026-07-13 SKW6409 - Jul 13, 16:25 UTCJul 13, 19:05 UTC2h 40m
2026-07-13 SKW4951 - Jul 13, 12:40 UTCJul 13, 15:15 UTC2h 35m
2026-07-13 SKW4962 - Jul 13, 01:30 UTCJul 13, 04:40 UTC3h 10m
2026-07-12 SKW6366 - Jul 12, 20:40 UTCJul 12, 23:50 UTC3h 10m
2026-07-12 SKW6366 - Jul 12, 16:50 UTCJul 12, 19:40 UTC2h 50m
2026-07-12 SKW4895 - Jul 12, 12:35 UTCJul 12, 15:15 UTC2h 40m
2026-07-12 SKW4895 OKC → LAX Jul 12, 12:34 UTCJul 12, 15:12 UTC2h 38m
2026-07-12 SKW4898 LAX → OKC Jul 12, 00:25 UTCJul 12, 03:05 UTC2h 40m
2026-07-11 SKW6409 - Jul 11, 20:40 UTCJul 11, 23:20 UTC2h 40m
2026-07-11 SKW6409 - Jul 11, 17:00 UTCJul 11, 19:45 UTC2h 45m
2026-07-11 SKW6482 - Jul 11, 12:20 UTCJul 11, 15:35 UTC3h 15m
2026-07-11 SKW6187 - Jul 11, 01:05 UTCJul 11, 03:55 UTC2h 50m
2026-07-10 SKW6366 - Jul 10, 20:40 UTCJul 10, 23:35 UTC2h 55m
2026-07-10 SKW6366 - Jul 10, 17:00 UTCJul 10, 19:40 UTC2h 40m
2026-07-10 SKW4895 - Jul 10, 12:45 UTCJul 10, 15:25 UTC2h 40m
2026-07-10 SKW4898 - Jul 10, 00:30 UTCJul 10, 03:15 UTC2h 45m
2026-07-09 SKW6409 - Jul 9, 20:40 UTCJul 9, 23:30 UTC2h 50m
2026-07-09 SKW6409 - Jul 9, 16:30 UTCJul 9, 19:10 UTC2h 40m
2026-07-09 SKW4958 - Jul 9, 02:05 UTCJul 9, 03:55 UTC1h 50m
2026-07-09 SKW4958 DEN → LAX Jul 9, 02:00 UTCJul 9, 03:56 UTC1h 56m
2026-07-08 SKW4958 - Jul 8, 23:05 UTCJul 9, 01:00 UTC1h 55m
2026-07-08 SKW6188 - Jul 8, 20:45 UTCJul 8, 21:45 UTC1h 0m
2026-07-08 SKW6188 SFO → LAX Jul 8, 20:55 UTCJul 8, 21:37 UTC42m
2026-07-08 SKW6188 - Jul 8, 18:55 UTCJul 8, 19:55 UTC1h 0m
2026-07-08 SKW6336 - Jul 8, 16:25 UTCJul 8, 17:20 UTC55m
2026-07-08 SKW6336 - Jul 8, 14:25 UTCJul 8, 15:30 UTC1h 5m
2026-07-08 SKW5005 - Jul 8, 01:45 UTCJul 8, 04:50 UTC3h 5m
2026-07-08 SKW5005 IAH → LAX Jul 8, 01:43 UTCJul 8, 04:44 UTC3h 1m
2026-07-07 SKW5005 - Jul 7, 21:20 UTCJul 8, 00:30 UTC3h 10m
2026-07-07 SKW6330 - Jul 7, 19:10 UTCJul 7, 20:05 UTC55m
2026-07-07 SKW6330 SFO → LAX Jul 7, 18:53 UTCJul 7, 20:05 UTC1h 12m
2026-07-07 SKW6330 - Jul 7, 16:55 UTCJul 7, 18:00 UTC1h 5m
2026-07-07 SKW4919 - Jul 7, 13:15 UTCJul 7, 14:50 UTC1h 35m
2026-07-07 SKW4919 ABQ → LAX Jul 7, 13:11 UTCJul 7, 14:55 UTC1h 44m
2026-07-07 SKW296Y - Jul 7, 03:25 UTCJul 7, 05:00 UTC1h 35m
2026-07-07 SKW4946 - Jul 7, 01:35 UTCJul 7, 02:20 UTC45m
2026-07-07 SKW4946 LAS → LAX Jul 7, 01:35 UTCJul 7, 02:17 UTC42m
2026-07-06 SKW6190 - Jul 6, 23:55 UTCJul 7, 00:40 UTC45m
2026-07-06 6188 - Jul 6, 21:40 UTCJul 6, 22:40 UTC1h 0m
2026-07-06 SKW6188 - Jul 6, 19:45 UTCJul 6, 20:40 UTC55m
2026-07-06 SKW6336 - Jul 6, 16:25 UTCJul 6, 17:25 UTC1h 0m
2026-07-06 SKW6336 - Jul 6, 14:25 UTCJul 6, 15:20 UTC55m
2026-07-06 SKW4971 - Jul 6, 00:10 UTCJul 6, 03:20 UTC3h 10m
2026-07-05 SKW4971 - Jul 5, 19:50 UTCJul 5, 23:00 UTC3h 10m
2026-07-05 SKW6428 - Jul 5, 17:25 UTCJul 5, 18:15 UTC50m
2026-07-05 SKW6428 SFO → LAX Jul 5, 17:20 UTCJul 5, 18:20 UTC1h 0m
2026-07-05 SKW4911 - Jul 5, 14:40 UTCJul 5, 16:30 UTC1h 50m
2026-07-05 SKW6328 - Jul 5, 12:20 UTCJul 5, 13:15 UTC55m

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 N506SY page for operator, model, and routing details .

Mode-S A651E1 frequently asked

What is Mode-S code A651E1?
A651E1 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N506SY.
Where is Mode-S A651E1 registered?
Mode-S code A651E1 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 A651E1 broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A651E1, octal 51450741, decimal 10,899,937.
What flights does A651E1 operate?
Mode-S A651E1 has broadcast 20 distinct callsigns, including SKW6409, SKW5005, SKW6366, SKW6353, SKW6272.