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sensors Mode-S transponder

A1B948

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N21XT · EXTRA EA-300/330/350 · operated by VEGAS EXTREME ADVENTURES LLC

Hex
A1B948
Octal
50334510
Decimal
10,598,728
Country
US
Tail
N21XT
Type
E300
Transponder active on ground
Flights observed
97
Distinct callsigns
1
Country
US
Last broadcast
Jul 26, 15:35 UTC

Last known position

Most recent position reported by Mode-S A1B948.

Country allocation

The ICAO 24-bit address A1B948 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 1 distinct

Callsign Airline Flights Last seen
N21XT - 97 2026-07-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 N21XT VGT → VGT Jul 26, 15:00 UTCJul 26, 15:35 UTC35m
2026-07-25 N21XT - Jul 25, 20:50 UTCJul 25, 21:15 UTC25m
2026-07-25 N21XT - Jul 25, 19:40 UTCJul 25, 19:50 UTC10m
2026-07-24 N21XT - Jul 24, 16:35 UTCJul 24, 16:55 UTC20m
2026-07-20 N21XT - Jul 20, 20:55 UTCJul 20, 21:15 UTC20m
2026-07-20 N21XT - Jul 20, 17:25 UTCJul 20, 17:45 UTC20m
2026-07-20 N21XT - Jul 20, 16:20 UTCJul 20, 16:40 UTC20m
2026-07-19 N21XT - Jul 19, 23:35 UTCJul 20, 00:00 UTC25m
2026-07-19 N21XT - Jul 19, 22:45 UTCJul 19, 23:15 UTC30m
2026-07-19 N21XT VGT → VGT Jul 19, 16:50 UTCJul 19, 17:30 UTC40m
2026-07-18 N21XT - Jul 18, 20:45 UTCJul 18, 21:00 UTC15m
2026-07-18 N21XT - Jul 18, 17:35 UTCJul 18, 17:45 UTC10m
2026-07-17 N21XT VGT → VGT Jul 17, 21:44 UTCJul 17, 22:29 UTC45m
2026-07-17 N21XT - Jul 17, 18:34 UTCJul 17, 18:44 UTC10m
2026-07-17 N21XT - Jul 17, 16:40 UTCJul 17, 17:09 UTC30m
2026-07-16 N21XT VGT → VGT Jul 16, 19:45 UTCJul 16, 20:05 UTC20m
2026-07-16 N21XT VGT → VGT Jul 16, 18:50 UTCJul 16, 19:10 UTC20m
2026-07-16 N21XT - Jul 16, 16:19 UTCJul 16, 16:44 UTC25m
2026-07-12 N21XT VGT → VGT Jul 12, 16:40 UTCJul 12, 17:01 UTC20m
2026-07-11 N21XT - Jul 11, 15:30 UTCJul 11, 15:35 UTC5m
2026-07-10 N21XT - Jul 10, 18:10 UTCJul 10, 18:50 UTC40m
2026-07-06 N21XT - Jul 6, 17:20 UTCJul 6, 17:55 UTC35m
2026-07-05 N21XT VGT → VGT Jul 5, 19:25 UTCJul 5, 19:45 UTC20m
2026-07-05 N21XT VGT → VGT Jul 5, 16:20 UTCJul 5, 16:50 UTC30m
2026-07-04 N21XT - Jul 4, 19:40 UTCJul 4, 20:00 UTC20m
2026-07-04 N21XT VGT → VGT Jul 4, 17:00 UTCJul 4, 17:20 UTC20m
2026-07-03 N21XT - Jul 3, 19:35 UTCJul 3, 20:20 UTC45m
2026-07-03 N21XT - Jul 3, 18:10 UTCJul 3, 18:20 UTC10m
2026-07-03 N21XT - Jul 3, 16:30 UTCJul 3, 16:55 UTC25m
2026-07-01 N21XT - Jul 1, 23:20 UTCJul 1, 23:35 UTC15m
2026-07-01 N21XT - Jul 1, 16:30 UTCJul 1, 16:40 UTC10m
2026-07-01 N21XT - Jul 1, 14:55 UTCJul 1, 15:05 UTC10m
2026-06-30 N21XT - Jun 30, 17:05 UTCJun 30, 17:20 UTC15m
2026-06-30 N21XT - Jun 30, 15:20 UTCJun 30, 15:30 UTC10m
2026-06-29 N21XT - Jun 29, 17:49 UTCJun 29, 18:14 UTC25m
2026-06-29 N21XT - Jun 29, 16:59 UTCJun 29, 17:10 UTC10m
2026-06-29 N21XT - Jun 29, 16:15 UTCJun 29, 16:25 UTC10m
2026-06-28 N21XT - Jun 28, 16:09 UTCJun 28, 16:19 UTC10m
2026-06-28 N21XT - Jun 28, 14:14 UTCJun 28, 14:25 UTC10m
2026-06-27 N21XT - Jun 27, 15:45 UTCJun 27, 16:10 UTC25m
2026-06-27 N21XT - Jun 27, 14:09 UTCJun 27, 14:20 UTC10m
2026-06-04 N21XT VGT → VGT Jun 4, 21:25 UTCJun 4, 22:00 UTC35m
2026-06-04 N21XT VGT → VGT Jun 4, 17:40 UTCJun 4, 18:10 UTC30m
2026-06-04 N21XT VGT → VGT Jun 4, 16:25 UTCJun 4, 17:00 UTC35m
2026-06-04 N21XT VGT → VGT Jun 4, 14:20 UTCJun 4, 14:45 UTC25m
2026-06-01 N21XT - Jun 1, 19:25 UTCJun 1, 20:00 UTC35m
2026-05-31 N21XT VGT → VGT May 31, 16:35 UTCMay 31, 16:55 UTC20m
2026-05-30 N21XT - May 30, 19:05 UTCMay 30, 19:30 UTC25m
2026-05-30 N21XT - May 30, 16:40 UTCMay 30, 17:00 UTC20m
2026-05-29 N21XT - May 29, 17:55 UTCMay 29, 18:35 UTC40m

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 N21XT page for operator, model, and routing details .

Mode-S A1B948 frequently asked

What is Mode-S code A1B948?
A1B948 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N21XT.
Where is Mode-S A1B948 registered?
Mode-S code A1B948 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 A1B948 broadcasting right now?
Mode-S A1B948 is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A1B948, octal 50334510, decimal 10,598,728.
What flights does A1B948 operate?
Mode-S A1B948 has broadcast 1 distinct callsign, including N21XT.