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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 Jul 26, 21:00 UTC
Flights observed
782
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:00 UTC

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 - 11 2026-07-15
SKW6261 SkyWest Airlines 11 2026-07-23
SKW6433 SkyWest Airlines 10 2026-07-01
SKW6419 SkyWest Airlines 10 2026-07-22
SKW4990 - 10 2026-07-08
SKW4949 - 10 2026-06-28
SKW6348 SkyWest Airlines 9 2026-06-12
SKW6338 SkyWest Airlines 9 2026-07-06
SKW6337 - 9 2026-07-17
SKW6465 SkyWest Airlines 8 2026-05-15
SKW6452 SkyWest Airlines 8 2026-05-16
SKW6396 - 8 2026-07-06
SKW6391 SkyWest Airlines 8 2026-07-23
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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW6394 LAX → DEN Jul 26, 19:45 UTCJul 26, 20:55 UTC1h 10m
2026-07-26 SKW6394 LAX → DEN Jul 26, 17:15 UTCJul 26, 18:15 UTC1h 0m
2026-07-26 SKW6406 PSP → PHX Jul 26, 14:00 UTCJul 26, 14:40 UTC40m
2026-07-26 SKW4922 SLC → PHX Jul 26, 05:50 UTCJul 26, 06:30 UTC40m
2026-07-26 SKW6276 LAX → SFO Jul 26, 02:50 UTCJul 26, 04:40 UTC1h 50m
2026-07-25 SKW6487 DFW → AEX Jul 25, 23:55 UTCJul 26, 01:30 UTC1h 35m
2026-07-25 SKW4833 LWB → ORD Jul 25, 20:25 UTCJul 25, 21:35 UTC1h 10m
2026-07-25 SKW4833 LWB → ORD Jul 25, 20:36 UTCJul 25, 21:35 UTC59m
2026-07-25 SKW4830 CLT → LWB Jul 25, 18:55 UTCJul 25, 19:25 UTC30m
2026-07-25 SKW6247 - Jul 25, 14:55 UTCJul 25, 15:55 UTC1h 0m
2026-07-25 SKW6247 CMH → CLT Jul 25, 14:59 UTCJul 25, 15:51 UTC52m
2026-07-25 SKW6247 - Jul 25, 13:00 UTCJul 25, 13:50 UTC50m
2026-07-25 SKW4827 SHD → CLT Jul 25, 09:35 UTCJul 25, 10:25 UTC50m
2026-07-25 SKW4827 SHD → CLT Jul 25, 09:28 UTCJul 25, 10:22 UTC54m
2026-07-25 SKW4832 ORD → SHD Jul 25, 00:55 UTCJul 25, 02:10 UTC1h 15m
2026-07-24 SKW4913 PHX → YUM Jul 24, 22:05 UTCJul 24, 23:25 UTC1h 20m
2026-07-24 SKW4913 PHX → YUM Jul 24, 19:45 UTCJul 24, 20:50 UTC1h 5m
2026-07-24 SKW5014 HRL → DFW Jul 24, 17:15 UTCJul 24, 18:25 UTC1h 10m
2026-07-24 SKW5014 HRL → DFW Jul 24, 17:11 UTCJul 24, 18:24 UTC1h 13m
2026-07-24 SKW5014 HRL → DFW Jul 24, 14:55 UTCJul 24, 16:00 UTC1h 5m
2026-07-24 SKW6251 PHX → SLC Jul 24, 10:50 UTCJul 24, 12:40 UTC1h 50m
2026-07-24 SKW4943 PIA → ORD Jul 24, 02:20 UTCJul 24, 03:50 UTC1h 30m
2026-07-24 SKW4943 PIA → ORD Jul 24, 02:15 UTCJul 24, 03:50 UTC1h 35m
2026-07-23 SKW6230 DFW → OKC Jul 23, 23:55 UTCJul 24, 00:40 UTC45m
2026-07-23 SKW6230 DFW → OKC Jul 23, 21:20 UTCJul 23, 22:00 UTC40m
2026-07-23 SKW6261 DFW → SBN Jul 23, 18:25 UTCJul 23, 18:50 UTC25m
2026-07-23 SKW6261 DFW → SBN Jul 23, 18:24 UTCJul 23, 18:47 UTC23m
2026-07-23 SKW6261 DFW → SBN Jul 23, 17:00 UTCJul 23, 17:20 UTC20m
2026-07-23 SKW6391 TUS → LAX Jul 23, 14:20 UTCJul 23, 14:55 UTC35m
2026-07-23 SKW6391 TUS → LAX Jul 23, 14:16 UTCJul 23, 14:43 UTC27m
2026-07-23 SKW6391 TUS → LAX Jul 23, 12:35 UTCJul 23, 13:05 UTC30m
2026-07-23 SKW6358 MKE → ORD Jul 23, 10:25 UTCJul 23, 10:55 UTC30m
2026-07-23 SKW6358 MKE → ORD Jul 23, 10:20 UTCJul 23, 10:49 UTC29m
2026-07-23 SKW4888 - Jul 23, 00:50 UTCJul 23, 01:15 UTC25m
2026-07-22 SKW4913 PHX → YUM Jul 22, 21:15 UTCJul 22, 22:30 UTC1h 15m
2026-07-22 SKW4913 PHX → YUM Jul 22, 18:45 UTCJul 22, 19:50 UTC1h 5m
2026-07-22 SKW6225 - Jul 22, 13:45 UTCJul 22, 15:40 UTC1h 55m
2026-07-22 SKW6225 ASE → ORD Jul 22, 13:38 UTCJul 22, 15:39 UTC2h 1m
2026-07-22 SKW6419 PHX → IAH Jul 22, 00:20 UTCJul 22, 01:40 UTC1h 20m
2026-07-22 SKW6419 PHX → IAH Jul 22, 00:16 UTCJul 22, 01:56 UTC1h 40m
2026-07-21 SKW4912 DFW → SBN Jul 21, 20:35 UTCJul 21, 22:05 UTC1h 30m
2026-07-21 SKW4912 DFW → SBN Jul 21, 16:10 UTCJul 21, 17:30 UTC1h 20m
2026-07-21 SKW6302 ABQ → LAX Jul 21, 11:45 UTCJul 21, 13:10 UTC1h 25m
2026-07-21 SKW4981 PHX → CID Jul 21, 02:40 UTCJul 21, 04:00 UTC1h 20m
2026-07-21 SKW6344 PHX → SJC Jul 21, 00:15 UTCJul 21, 01:00 UTC45m
2026-07-20 SKW6344 PHX → SJC Jul 20, 23:56 UTCJul 21, 00:52 UTC56m
2026-07-20 SKW6344 PHX → SJC Jul 20, 22:40 UTCJul 20, 23:10 UTC30m
2026-07-20 SKW4965 LCH → DFW Jul 20, 19:10 UTCJul 20, 20:40 UTC1h 30m
2026-07-20 SKW4965 LCH → DFW Jul 20, 16:30 UTCJul 20, 17:40 UTC1h 10m
2026-07-20 SKW4917 PVU → DFW Jul 20, 12:45 UTCJul 20, 15:05 UTC2h 20m

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 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 AA21EF, octal 52420757, decimal 11,149,807.
What flights does AA21EF operate?
Mode-S AA21EF has broadcast 20 distinct callsigns, including SKW5003, SKW6466, SKW6261, SKW6433, SKW6419.