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sensors Mode-S transponder

AA21EF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N752EV · BOMBARDIER Regional Jet CRJ-700 · operated by SKYWEST AIRLINES INC

Hex
AA21EF
Octal
52420757
Decimal
11,149,807
Country
US
Tail
N752EV
Type
CRJ7
No current signal · last broadcast 23m ago
Flights observed
693
Distinct callsigns
20
Country
US
Last broadcast
23m ago

Last known position

Most recent position reported by Mode-S AA21EF.

Country allocation

The ICAO 24-bit address AA21EF 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
SKW5003 - 12 2026-07-06
SKW6466 - 10 2026-07-12
SKW6433 SkyWest Airlines 10 2026-07-01
SKW4990 - 10 2026-07-08
SKW4949 - 10 2026-06-28
SKW6348 SkyWest Airlines 9 2026-06-12
SKW6338 SkyWest Airlines 9 2026-07-06
SKW6465 SkyWest Airlines 8 2026-05-15
SKW6452 SkyWest Airlines 8 2026-05-16
SKW6419 SkyWest Airlines 8 2026-06-26
SKW6396 - 8 2026-07-06
SKW6261 SkyWest Airlines 8 2026-06-30
SKW6192 SkyWest Airlines 8 2026-05-28
SKW5012 SkyWest Airlines 8 2026-06-13
SKW4955 - 8 2026-07-07
SKW6445 - 7 2026-06-16
SKW6410 - 7 2026-07-11
SKW6399 - 7 2026-07-06
SKW6250 - 7 2026-06-28
SKW4953 - 7 2026-06-30

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 SKW238P - Jul 14, 04:05 UTCJul 14, 05:45 UTC1h 40m
2026-07-13 SKW4985 - Jul 13, 22:35 UTCJul 13, 23:05 UTC30m
2026-07-13 SKW4985 - Jul 13, 21:25 UTCJul 13, 21:50 UTC25m
2026-07-13 SKW6383 - Jul 13, 19:30 UTCJul 13, 20:00 UTC30m
2026-07-13 SKW6383 - Jul 13, 18:15 UTCJul 13, 18:35 UTC20m
2026-07-13 SKW6392 OKC → PHX Jul 13, 15:30 UTCJul 13, 17:10 UTC1h 40m
2026-07-13 SKW6392 OKC → PHX Jul 13, 15:25 UTCJul 13, 17:15 UTC1h 50m
2026-07-13 SKW6206 - Jul 13, 13:55 UTCJul 13, 14:40 UTC45m
2026-07-13 SKW6206 DFW → OKC Jul 13, 13:53 UTCJul 13, 14:34 UTC41m
2026-07-13 SKW6234 LAW → DFW Jul 13, 04:40 UTCJul 13, 05:15 UTC35m
2026-07-13 SKW6234 LAW → DFW Jul 13, 03:09 UTCJul 13, 05:10 UTC2h 1m
2026-07-12 SKW6234 - Jul 12, 22:55 UTCJul 12, 23:20 UTC25m
2026-07-12 SKW6238 - Jul 12, 20:10 UTCJul 12, 21:30 UTC1h 20m
2026-07-12 SKW6238 - Jul 12, 17:40 UTCJul 12, 18:50 UTC1h 10m
2026-07-12 SKW6466 - Jul 12, 13:30 UTCJul 12, 15:40 UTC2h 10m
2026-07-12 SKW6466 IDA → DFW Jul 12, 13:15 UTCJul 12, 15:42 UTC2h 27m
2026-07-12 SKW6467 - Jul 12, 01:55 UTCJul 12, 04:10 UTC2h 15m
2026-07-11 SKW6410 AUS → DFW Jul 11, 23:40 UTCJul 12, 00:18 UTC38m
2026-07-11 SKW6410 AUS → DFW Jul 11, 23:40 UTCJul 12, 00:30 UTC50m
2026-07-11 SKW6205 - Jul 11, 20:35 UTCJul 11, 22:15 UTC1h 40m
2026-07-11 SKW6427 - Jul 11, 16:30 UTCJul 11, 18:40 UTC2h 10m
2026-07-11 SKW4969 - Jul 11, 14:00 UTCJul 11, 14:50 UTC50m
2026-07-11 SKW4969 ORD → DSM Jul 11, 12:00 UTCJul 11, 12:50 UTC50m
2026-07-11 SKW4904 - Jul 11, 09:45 UTCJul 11, 10:35 UTC50m
2026-07-11 SKW4916 - Jul 11, 02:55 UTCJul 11, 03:35 UTC40m
2026-07-11 SKW6380 - Jul 11, 00:00 UTCJul 11, 00:45 UTC45m
2026-07-10 SKW6380 - Jul 10, 22:35 UTCJul 10, 23:05 UTC30m
2026-07-10 SKW6519 OKC → ORD Jul 10, 19:15 UTCJul 10, 21:10 UTC1h 55m
2026-07-10 SKW6519 OKC → ORD Jul 10, 19:10 UTCJul 10, 21:03 UTC1h 53m
2026-07-10 SKW6277 PHX → OKC Jul 10, 16:29 UTCJul 10, 18:15 UTC1h 46m
2026-07-10 SKW6277 - Jul 10, 16:30 UTCJul 10, 17:45 UTC1h 15m
2026-07-10 SKW6505 - Jul 10, 14:05 UTCJul 10, 14:35 UTC30m
2026-07-10 SKW6505 YUM → PHX Jul 10, 14:01 UTCJul 10, 14:31 UTC30m
2026-07-10 SKW6509 - Jul 10, 03:15 UTCJul 10, 03:35 UTC20m
2026-07-10 SKW6354 SMF → PHX Jul 10, 00:15 UTCJul 10, 01:45 UTC1h 30m
2026-07-10 SKW6354 SMF → PHX Jul 10, 00:09 UTCJul 10, 01:45 UTC1h 36m
2026-07-09 SKW6354 PHX → SMF Jul 9, 21:50 UTCJul 9, 23:30 UTC1h 40m
2026-07-09 SKW6473 - Jul 9, 18:35 UTCJul 9, 20:30 UTC1h 55m
2026-07-09 SKW6473 ICT → PHX Jul 9, 18:37 UTCJul 9, 20:26 UTC1h 49m
2026-07-09 SKW5007 - Jul 9, 16:25 UTCJul 9, 17:50 UTC1h 25m
2026-07-09 SKW4964 - Jul 9, 14:00 UTCJul 9, 15:20 UTC1h 20m
2026-07-09 SKW6326 - Jul 9, 01:35 UTCJul 9, 02:40 UTC1h 5m
2026-07-09 SKW6326 ORD → BNA Jul 9, 01:34 UTCJul 9, 02:37 UTC1h 3m
2026-07-08 SKW6229 - Jul 8, 22:40 UTCJul 8, 23:10 UTC30m
2026-07-08 SKW6229 - Jul 8, 20:50 UTCJul 8, 21:15 UTC25m
2026-07-08 SKW6204 OKC → ORD Jul 8, 16:55 UTCJul 8, 18:35 UTC1h 40m
2026-07-08 SKW6204 OKC → ORD Jul 8, 16:54 UTCJul 8, 18:16 UTC1h 22m
2026-07-08 SKW6204 - Jul 8, 14:35 UTCJul 8, 16:05 UTC1h 30m
2026-07-08 SKW6223 - Jul 8, 10:25 UTCJul 8, 11:30 UTC1h 5m
2026-07-08 SKW6223 ERI → ORD Jul 8, 10:28 UTCJul 8, 11:46 UTC1h 18m

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 N752EV page for operator, model, and routing details .

Mode-S AA21EF frequently asked

What is Mode-S code AA21EF?
AA21EF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N752EV.
Where is Mode-S AA21EF registered?
Mode-S code AA21EF 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 AA21EF broadcasting right now?
No active broadcast right now. Last signal was 23m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex AA21EF, octal 52420757, decimal 11,149,807.
What flights does AA21EF operate?
Mode-S AA21EF has broadcast 20 distinct callsigns, including SKW5003, SKW6466, SKW6433, SKW4990, SKW4949.