Apparatus

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sensors Mode-S transponder

A2F721

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N290SY · EMBRAER ERJ-170-200 (long wing) · operated by SKYWEST AIRLINES INC

Hex
A2F721
Octal
50573441
Decimal
10,680,097
Country
US
Tail
N290SY
Type
E75L
No current signal · last broadcast Jul 26, 22:15 UTC
Flights observed
724
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 22:15 UTC

Last known position

Most recent position reported by Mode-S A2F721.

Country allocation

The ICAO 24-bit address A2F721 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
SKW4125 - 23 2026-07-22
SKW3857 SkyWest Airlines 22 2026-06-04
SKW3852 - 15 2026-07-06
SKW3933 - 14 2026-07-13
SKW3735 SkyWest Airlines 14 2026-07-24
SKW3777 - 13 2026-07-05
SKW4062 SkyWest Airlines 12 2026-06-08
SKW4042 SkyWest Airlines 12 2026-07-26
SKW3987 SkyWest Airlines 12 2026-06-03
SKW146A SkyWest Airlines 11 2026-06-03
SKW4138 - 10 2026-06-26
SKW3774 - 10 2026-06-26
SKW3732 - 10 2026-07-14
SKW3707 SkyWest Airlines 10 2026-05-05
SKW4019 - 9 2026-07-18
SKW3786 SkyWest Airlines 9 2026-05-25
SKW3719 SkyWest Airlines 9 2026-07-01
SKW3584 - 9 2026-07-07
SKW4153 SkyWest Airlines 8 2026-07-21
SKW4036 SkyWest Airlines 8 2026-06-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW4449 SLC → COS Jul 26, 22:10 UTCJul 26, 22:15 UTC5m
2026-07-26 SKW4042 MFR → SEA Jul 26, 19:40 UTCJul 26, 20:50 UTC1h 10m
2026-07-26 SKW4042 MFR → SEA Jul 26, 16:55 UTCJul 26, 18:15 UTC1h 20m
2026-07-26 SKW4029 SJC → SLC Jul 26, 13:45 UTCJul 26, 15:45 UTC2h 0m
2026-07-26 SKW3703 BOS → EWR Jul 26, 02:25 UTCJul 26, 04:20 UTC1h 55m
2026-07-25 SKW4104 ORD → JFK Jul 25, 21:20 UTCJul 26, 01:35 UTC4h 15m
2026-07-25 SKW156H GEG → SEA Jul 25, 17:00 UTCJul 25, 17:50 UTC50m
2026-07-25 SKW3830 OAK → LAX Jul 25, 14:35 UTCJul 25, 15:20 UTC45m
2026-07-25 SKW4043 HPN → ATL Jul 25, 06:55 UTCJul 25, 08:15 UTC1h 20m
2026-07-25 SKW4131 HRL → AUS Jul 25, 03:55 UTCJul 25, 05:25 UTC1h 30m
2026-07-25 SKW3968 BOS → MKE Jul 25, 01:30 UTCJul 25, 02:00 UTC30m
2026-07-24 SKW3733 DTW → CMH Jul 24, 23:35 UTCJul 25, 00:10 UTC35m
2026-07-24 SKW3735 SJC → LAX Jul 24, 20:50 UTCJul 24, 21:40 UTC50m
2026-07-24 SKW3735 SJC → LAX Jul 24, 18:55 UTCJul 24, 19:40 UTC45m
2026-07-24 SKW4075 LAX → OAK Jul 24, 16:35 UTCJul 24, 18:00 UTC1h 25m
2026-07-24 SKW4131 HRL → AUS Jul 24, 03:45 UTCJul 24, 05:15 UTC1h 30m
2026-07-24 SKW3968 BOS → MKE Jul 24, 01:10 UTCJul 24, 01:35 UTC25m
2026-07-23 SKW3733 DTW → CMH Jul 23, 23:25 UTCJul 24, 00:00 UTC35m
2026-07-23 SKW3735 SJC → LAX Jul 23, 20:50 UTCJul 23, 21:45 UTC55m
2026-07-23 SKW3735 SJC → LAX Jul 23, 19:00 UTCJul 23, 19:50 UTC50m
2026-07-23 SKW4075 LAX → OAK Jul 23, 15:35 UTCJul 23, 17:05 UTC1h 30m
2026-07-23 SKW4131 HRL → AUS Jul 23, 04:05 UTCJul 23, 05:40 UTC1h 35m
2026-07-23 SKW3968 BOS → MKE Jul 23, 01:30 UTCJul 23, 02:05 UTC35m
2026-07-22 SKW3733 DTW → CMH Jul 22, 23:50 UTCJul 23, 00:15 UTC25m
2026-07-22 SKW4125 SMF → SEA Jul 22, 20:10 UTCJul 22, 21:30 UTC1h 20m
2026-07-22 SKW4125 SEA → SMF Jul 22, 17:35 UTCJul 22, 19:10 UTC1h 35m
2026-07-22 SKW4092 SEA → SEA Jul 22, 03:20 UTCJul 22, 16:05 UTC12h 45m
2026-07-22 SKW3968 BOS → MKE Jul 22, 01:00 UTCJul 22, 01:35 UTC35m
2026-07-21 SKW3733 DTW → CMH Jul 21, 23:35 UTCJul 22, 00:05 UTC30m
2026-07-21 SKW4125 SMF → SEA Jul 21, 20:10 UTCJul 21, 21:35 UTC1h 25m
2026-07-21 SKW4125 SEA → SMF Jul 21, 17:30 UTCJul 21, 19:00 UTC1h 30m
2026-07-21 SKW3816 - Jul 21, 13:45 UTCJul 21, 15:50 UTC2h 5m
2026-07-21 SKW3884 SEA → ONT Jul 21, 03:45 UTCJul 21, 06:00 UTC2h 15m
2026-07-21 SKW4153 OAK → LAX Jul 21, 00:40 UTCJul 21, 02:00 UTC1h 20m
2026-07-20 SKW4153 OAK → LAX Jul 20, 22:05 UTCJul 20, 23:40 UTC1h 35m
2026-07-20 SKW3736 - Jul 20, 19:10 UTCJul 20, 20:15 UTC1h 5m
2026-07-20 SKW3736 SJC → SEA Jul 20, 19:09 UTCJul 20, 20:34 UTC1h 25m
2026-07-20 SKW3736 SEA → SJC Jul 20, 16:20 UTCJul 20, 18:20 UTC2h 0m
2026-07-20 SKW118R BOI → SEA Jul 20, 13:10 UTCJul 20, 14:15 UTC1h 5m
2026-07-20 SKW4446 - Jul 20, 03:30 UTCJul 20, 04:15 UTC45m
2026-07-20 SKW148E ATL → HPN Jul 20, 01:20 UTCJul 20, 02:00 UTC40m
2026-07-19 SKW166C - Jul 19, 22:15 UTCJul 19, 22:55 UTC40m
2026-07-19 SKW4042 - Jul 19, 19:35 UTCJul 19, 20:45 UTC1h 10m
2026-07-19 SKW4042 - Jul 19, 17:10 UTCJul 19, 18:15 UTC1h 5m
2026-07-19 SKW4061 OAK → SLC Jul 19, 13:10 UTCJul 19, 14:30 UTC1h 20m
2026-07-19 SKW3797 SLC → OAK Jul 19, 02:56 UTCJul 19, 04:15 UTC1h 19m
2026-07-19 SKW3797 SLC → OAK Jul 19, 02:50 UTCJul 19, 04:15 UTC1h 25m
2026-07-19 SKW3853 SBA → SLC Jul 19, 00:00 UTCJul 19, 01:40 UTC1h 40m
2026-07-18 SKW3853 SLC → SBA Jul 18, 21:15 UTCJul 18, 23:00 UTC1h 45m
2026-07-18 SKW4019 - Jul 18, 19:25 UTCJul 18, 20:00 UTC35m

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 N290SY page for operator, model, and routing details .

Mode-S A2F721 frequently asked

What is Mode-S code A2F721?
A2F721 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N290SY.
Where is Mode-S A2F721 registered?
Mode-S code A2F721 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 A2F721 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 A2F721, octal 50573441, decimal 10,680,097.
What flights does A2F721 operate?
Mode-S A2F721 has broadcast 20 distinct callsigns, including SKW4125, SKW3857, SKW3852, SKW3933, SKW3735.