Apparatus

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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 Jul 26, 22:15 UTC
Flights observed
654
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:15 UTC

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 SkyWest Airlines 29 2026-07-22
SKW5005 - 15 2026-07-08
SKW6366 - 13 2026-07-12
SKW6353 SkyWest Airlines 13 2026-05-08
SKW6307 SkyWest Airlines 13 2026-07-26
SKW4895 SkyWest Airlines 13 2026-07-23
SKW6428 SkyWest Airlines 12 2026-07-21
SKW6381 SkyWest Airlines 12 2026-07-25
SKW6272 - 12 2026-07-01
SKW4991 SkyWest Airlines 12 2026-05-21
SKW6482 - 11 2026-07-11
SKW4898 SkyWest Airlines 11 2026-07-23
SKW6185 - 10 2026-07-02
SKW6415 SkyWest Airlines 9 2026-06-15
SKW6330 - 9 2026-07-07
SKW6278 SkyWest Airlines 9 2026-07-24
SKW6187 - 9 2026-07-11
SKW4995 SkyWest Airlines 9 2026-07-19
SKW4979 - 9 2026-07-01
SKW4971 SkyWest Airlines 9 2026-07-22

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW6307 DFW → SHV Jul 26, 20:20 UTCJul 26, 22:15 UTC1h 55m
2026-07-26 SKW6307 DFW → SHV Jul 26, 16:40 UTCJul 26, 19:15 UTC2h 35m
2026-07-26 SKW4951 BNA → ORD Jul 26, 12:15 UTCJul 26, 14:15 UTC2h 0m
2026-07-26 SKW4951 BNA → ORD Jul 26, 12:13 UTCJul 26, 14:46 UTC2h 33m
2026-07-26 SKW4962 LAX → SAT Jul 26, 01:45 UTCJul 26, 04:25 UTC2h 40m
2026-07-26 SKW4962 LAX → SAT Jul 26, 01:43 UTCJul 26, 04:22 UTC2h 39m
2026-07-25 SKW6381 PHX → SEA Jul 25, 21:05 UTCJul 26, 00:05 UTC3h 0m
2026-07-25 SKW6381 PHX → SEA Jul 25, 21:02 UTCJul 26, 00:01 UTC2h 59m
2026-07-25 SKW6381 PHX → SEA Jul 25, 16:50 UTCJul 25, 20:00 UTC3h 10m
2026-07-25 SKW6293 LAX → SJC Jul 25, 11:45 UTCJul 25, 15:25 UTC3h 40m
2026-07-25 SKW5000 ORD → FSD Jul 25, 01:20 UTCJul 25, 04:50 UTC3h 30m
2026-07-24 SKW6278 PHX → BFL Jul 24, 21:05 UTCJul 25, 00:15 UTC3h 10m
2026-07-24 SKW6278 PHX → BFL Jul 24, 17:10 UTCJul 24, 20:05 UTC2h 55m
2026-07-24 SKW6293 LAX → SJC Jul 24, 11:55 UTCJul 24, 15:35 UTC3h 40m
2026-07-24 SKW6293 LAX → SJC Jul 24, 11:47 UTCJul 24, 15:29 UTC3h 42m
2026-07-24 SKW5000 ORD → FSD Jul 24, 01:30 UTCJul 24, 05:05 UTC3h 35m
2026-07-23 SKW6278 PHX → BFL Jul 23, 21:00 UTCJul 24, 00:10 UTC3h 10m
2026-07-23 SKW6278 PHX → BFL Jul 23, 17:00 UTCJul 23, 20:00 UTC3h 0m
2026-07-23 SKW4895 DFW → MFE Jul 23, 12:30 UTCJul 23, 15:30 UTC3h 0m
2026-07-23 SKW4898 TUL → ORD Jul 23, 00:30 UTCJul 23, 03:05 UTC2h 35m
2026-07-22 SKW6409 ORD → DTW Jul 22, 20:30 UTCJul 22, 23:05 UTC2h 35m
2026-07-22 SKW6409 ORD → DTW Jul 22, 16:25 UTCJul 22, 19:10 UTC2h 45m
2026-07-22 SKW4971 DFW → LRD Jul 22, 00:45 UTCJul 22, 04:05 UTC3h 20m
2026-07-22 SKW4971 DFW → LRD Jul 22, 00:44 UTCJul 22, 04:06 UTC3h 22m
2026-07-21 SKW4971 DFW → LRD Jul 21, 20:30 UTCJul 21, 23:35 UTC3h 5m
2026-07-21 SKW6428 PHX → SLC Jul 21, 18:26 UTCJul 21, 19:23 UTC57m
2026-07-21 SKW4911 DFW → DRO Jul 21, 15:40 UTCJul 21, 17:15 UTC1h 35m
2026-07-21 SKW6328 DRO → PHX Jul 21, 12:10 UTCJul 21, 13:08 UTC58m
2026-07-21 SKW6334 PHX → DRO Jul 21, 07:30 UTCJul 21, 08:15 UTC45m
2026-07-21 SKW6435 - Jul 21, 06:00 UTCJul 21, 06:25 UTC25m
2026-07-21 SKW6435 - Jul 21, 02:20 UTCJul 21, 04:15 UTC1h 55m
2026-07-21 SKW6435 PHX → SBP Jul 21, 00:10 UTCJul 21, 01:20 UTC1h 10m
2026-07-20 SKW4948 - Jul 20, 20:15 UTCJul 20, 22:10 UTC1h 55m
2026-07-20 SKW4948 BOI → PHX Jul 20, 20:17 UTCJul 20, 22:02 UTC1h 45m
2026-07-20 SKW4948 - Jul 20, 17:45 UTCJul 20, 19:20 UTC1h 35m
2026-07-20 SKW6475 PHX → DRO Jul 20, 14:35 UTCJul 20, 16:25 UTC1h 50m
2026-07-20 SKW6332 - Jul 20, 04:15 UTCJul 20, 04:30 UTC15m
2026-07-20 SKW6332 - Jul 20, 02:45 UTCJul 20, 03:30 UTC45m
2026-07-20 SKW6368 - Jul 20, 00:35 UTCJul 20, 01:00 UTC25m
2026-07-20 SKW6368 TUS → PHX Jul 20, 00:34 UTCJul 20, 00:58 UTC24m
2026-07-19 SKW6368 PHX → TUS Jul 19, 23:10 UTCJul 19, 23:40 UTC30m
2026-07-19 SKW4995 DFW → LAW Jul 19, 18:30 UTCJul 19, 19:30 UTC1h 0m
2026-07-19 SKW4995 DFW → LAW Jul 19, 18:19 UTCJul 19, 19:29 UTC1h 10m
2026-07-19 SKW4995 DFW → LAW Jul 19, 16:15 UTCJul 19, 17:10 UTC55m
2026-07-19 SKW6360 - Jul 19, 12:40 UTCJul 19, 14:45 UTC2h 5m
2026-07-19 SKW6292 - Jul 19, 04:10 UTCJul 19, 06:10 UTC2h 0m
2026-07-19 SKW4900 - Jul 19, 01:20 UTCJul 19, 01:45 UTC25m
2026-07-19 SKW4900 TUS → PHX Jul 19, 01:15 UTCJul 19, 01:41 UTC26m
2026-07-19 SKW6368 - Jul 19, 00:00 UTCJul 19, 00:30 UTC30m
2026-07-18 SKW6368 PHX → TUS Jul 18, 23:57 UTCJul 19, 00:29 UTC32m

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 Jul 26, 22:15 UTC.
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, SKW6307.