Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

A276DD

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N258SY · EMBRAER ERJ-170-200 (long wing) · operated by SKYWEST AIRLINES INC

Hex
A276DD
Octal
50473335
Decimal
10,647,261
Country
US
Tail
N258SY
Type
E75L
No current signal · last broadcast Jul 26, 21:15 UTC
Flights observed
685
Distinct callsigns
20
Country
US
Last broadcast
Jul 26, 21:15 UTC

Last known position

Most recent position reported by Mode-S A276DD.

Country allocation

The ICAO 24-bit address A276DD 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
SKW4127 SkyWest Airlines 13 2026-07-25
SKW4134 - 12 2026-07-01
SKW4087 - 11 2026-07-19
SKW4099 - 10 2026-07-18
SKW3802 SkyWest Airlines 10 2026-07-22
SKW3699 - 10 2026-07-06
SKW3953 - 9 2026-07-17
SKW3801 - 9 2026-07-14
SKW3707 SkyWest Airlines 9 2026-07-22
SKW3798 - 8 2026-06-20
SKW3806 - 7 2026-07-12
SKW3695 SkyWest Airlines 7 2026-07-25
SKW3685 SkyWest Airlines 7 2026-05-26
SKW4145 - 6 2026-07-08
SKW4112 SkyWest Airlines 6 2026-06-19
SKW4041 - 6 2026-07-22
SKW3923 - 6 2026-07-09
SKW3902 - 6 2026-07-18
SKW3688 SkyWest Airlines 6 2026-07-20
SKW4153 SkyWest Airlines 5 2026-05-27

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 SKW3841 RNO → LAX Jul 26, 20:05 UTCJul 26, 21:15 UTC1h 10m
2026-07-26 SKW3841 RNO → LAX Jul 26, 17:30 UTCJul 26, 19:10 UTC1h 40m
2026-07-26 SKW3607 SJC → LAX Jul 26, 14:35 UTCJul 26, 15:25 UTC50m
2026-07-25 SKW4446 SLC → BOI Jul 25, 23:55 UTCJul 26, 00:40 UTC45m
2026-07-25 SKW4155 SLC → BZN Jul 25, 20:55 UTCJul 25, 22:30 UTC1h 35m
2026-07-25 SKW4149 EUG → SEA Jul 25, 18:40 UTCJul 25, 19:30 UTC50m
2026-07-25 SKW3695 ORD → BOS Jul 25, 14:15 UTCJul 25, 16:30 UTC2h 15m
2026-07-25 SKW3695 ORD → BOS Jul 25, 14:09 UTCJul 25, 16:28 UTC2h 19m
2026-07-25 SKW3932 MSP → MOT Jul 25, 03:05 UTCJul 25, 05:35 UTC2h 30m
2026-07-25 SKW4127 MSP → PIT Jul 25, 01:50 UTCJul 25, 02:00 UTC10m
2026-07-25 SKW4127 MSP → PIT Jul 25, 00:40 UTCJul 25, 02:00 UTC1h 20m
2026-07-25 SKW4127 MSP → PIT Jul 25, 00:31 UTCJul 25, 01:35 UTC1h 4m
2026-07-24 SKW4127 MSP → PIT Jul 24, 22:17 UTCJul 24, 23:11 UTC54m
2026-07-24 SKW3754 MDT → DTW Jul 24, 20:20 UTCJul 24, 21:05 UTC45m
2026-07-24 SKW3754 MDT → DTW Jul 24, 18:10 UTCJul 24, 18:50 UTC40m
2026-07-24 SKW3695 ORD → BOS Jul 24, 14:25 UTCJul 24, 16:40 UTC2h 15m
2026-07-24 SKW3695 ORD → BOS Jul 24, 14:12 UTCJul 24, 16:34 UTC2h 22m
2026-07-24 SKW3932 MSP → MOT Jul 24, 02:55 UTCJul 24, 05:25 UTC2h 30m
2026-07-24 SKW127T MFR → SEA Jul 24, 00:35 UTCJul 24, 01:35 UTC1h 0m
2026-07-23 SKW3770 HPN → ATL Jul 23, 22:40 UTCJul 23, 23:45 UTC1h 5m
2026-07-23 SKW3754 MDT → DTW Jul 23, 20:10 UTCJul 23, 20:55 UTC45m
2026-07-23 SKW3754 MDT → DTW Jul 23, 18:30 UTCJul 23, 19:15 UTC45m
2026-07-23 SKW3695 ORD → BOS Jul 23, 14:45 UTCJul 23, 17:00 UTC2h 15m
2026-07-23 SKW3932 MSP → MOT Jul 23, 02:45 UTCJul 23, 05:15 UTC2h 30m
2026-07-23 SKW4127 MSP → PIT Jul 23, 00:05 UTCJul 23, 01:05 UTC1h 0m
2026-07-22 SKW4127 MSP → PIT Jul 22, 22:05 UTCJul 22, 23:15 UTC1h 10m
2026-07-22 SKW3802 SJC → SEA Jul 22, 19:45 UTCJul 22, 20:15 UTC30m
2026-07-22 SKW3802 SJC → SEA Jul 22, 17:55 UTCJul 22, 18:35 UTC40m
2026-07-22 SKW4041 SJC → SEA Jul 22, 14:55 UTCJul 22, 16:25 UTC1h 30m
2026-07-22 SKW4041 SJC → SEA Jul 22, 15:00 UTCJul 22, 16:24 UTC1h 24m
2026-07-22 SKW3956 DTW → LEX Jul 22, 03:50 UTCJul 22, 05:25 UTC1h 35m
2026-07-22 SKW3707 SJC → SEA Jul 22, 01:05 UTCJul 22, 02:30 UTC1h 25m
2026-07-21 SKW3707 SJC → SEA Jul 21, 22:10 UTCJul 22, 00:00 UTC1h 50m
2026-07-21 SKW3881 SMF → SEA Jul 21, 18:45 UTCJul 21, 20:00 UTC1h 15m
2026-07-21 SKW3881 SMF → SEA Jul 21, 18:43 UTCJul 21, 19:59 UTC1h 16m
2026-07-21 SKW164T SEA → SMF Jul 21, 16:05 UTCJul 21, 17:35 UTC1h 30m
2026-07-21 SKW3781 MFR → SEA Jul 21, 13:25 UTCJul 21, 14:10 UTC45m
2026-07-21 SKW3954 SEA → MFR Jul 21, 04:45 UTCJul 21, 05:55 UTC1h 10m
2026-07-21 SKW3954 SEA → MFR Jul 21, 04:49 UTCJul 21, 05:44 UTC55m
2026-07-21 SKW3999 MSN → DTW Jul 21, 01:00 UTCJul 21, 03:15 UTC2h 15m
2026-07-21 SKW3999 MSN → DTW Jul 21, 01:00 UTCJul 21, 03:03 UTC2h 3m
2026-07-20 SKW3999 MSN → DTW Jul 20, 21:15 UTCJul 20, 23:50 UTC2h 35m
2026-07-20 SKW183T - Jul 20, 18:40 UTCJul 20, 19:45 UTC1h 5m
2026-07-20 SKW183T BOI → SEA Jul 20, 18:43 UTCJul 20, 19:36 UTC53m
2026-07-20 SKW3678 BOS → CLE Jul 20, 16:20 UTCJul 20, 17:35 UTC1h 15m
2026-07-20 SKW4471 PDX → SEA Jul 20, 14:35 UTCJul 20, 15:00 UTC25m
2026-07-20 SKW3913 - Jul 20, 04:05 UTCJul 20, 04:40 UTC35m
2026-07-20 SKW3688 DTW → CMH Jul 20, 01:40 UTCJul 20, 02:45 UTC1h 5m
2026-07-19 SKW3688 DTW → CMH Jul 19, 23:35 UTCJul 20, 00:40 UTC1h 5m
2026-07-19 SKW3679 - Jul 19, 19:30 UTCJul 19, 22:10 UTC2h 40m

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 N258SY page for operator, model, and routing details .

Mode-S A276DD frequently asked

What is Mode-S code A276DD?
A276DD is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N258SY.
Where is Mode-S A276DD registered?
Mode-S code A276DD 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 A276DD broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A276DD, octal 50473335, decimal 10,647,261.
What flights does A276DD operate?
Mode-S A276DD has broadcast 20 distinct callsigns, including SKW4127, SKW4134, SKW4087, SKW4099, SKW3802.