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sensors Mode-S transponder

A4B19C

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N401NZ · operated by BETA TECHNOLOGIES INC

Hex
A4B19C
Octal
51130634
Decimal
10,793,372
Country
US
Tail
N401NZ
No current signal · last broadcast 8h ago
Flights observed
41
Distinct callsigns
1
Country
US
Last broadcast
8h ago

Last known position

Most recent position reported by Mode-S A4B19C.

Country allocation

The ICAO 24-bit address A4B19C 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
N401NZ - 41 2026-07-14

Recent flights last 41

DateFlightRouteTakeoffLandingDuration
2026-07-14 N401NZ - Jul 14, 00:40 UTCJul 14, 01:00 UTC20m
2026-07-13 N401NZ - Jul 13, 21:30 UTCJul 13, 21:40 UTC10m
2026-07-13 N401NZ - Jul 13, 18:50 UTCJul 13, 19:00 UTC10m
2026-07-12 N401NZ - Jul 12, 18:05 UTCJul 12, 18:20 UTC15m
2026-07-12 N401NZ - Jul 12, 16:40 UTCJul 12, 17:15 UTC35m
2026-07-10 N401NZ - Jul 10, 23:30 UTCJul 11, 00:05 UTC35m
2026-07-10 N401NZ - Jul 10, 19:40 UTCJul 10, 20:20 UTC40m
2026-07-09 N401NZ - Jul 9, 23:05 UTCJul 9, 23:50 UTC45m
2026-07-09 N401NZ - Jul 9, 04:20 UTCJul 9, 05:10 UTC50m
2026-07-07 N401NZ - Jul 7, 23:20 UTCJul 7, 23:55 UTC35m
2026-07-07 N401NZ - Jul 7, 19:30 UTCJul 7, 20:15 UTC45m
2026-07-06 N401NZ - Jul 6, 22:40 UTCJul 6, 23:20 UTC40m
2026-07-06 N401NZ - Jul 6, 19:05 UTCJul 6, 19:55 UTC50m
2026-07-05 N401NZ LNY → HNL Jul 5, 22:40 UTCJul 5, 23:20 UTC40m
2026-07-05 N401NZ - Jul 5, 18:40 UTCJul 5, 19:35 UTC55m
2026-07-04 N401NZ - Jul 4, 22:45 UTCJul 4, 23:20 UTC35m
2026-07-04 N401NZ - Jul 4, 19:05 UTCJul 4, 19:45 UTC40m
2026-07-03 N401NZ - Jul 3, 23:40 UTCJul 4, 00:20 UTC40m
2026-07-03 N401NZ - Jul 3, 19:30 UTCJul 3, 20:10 UTC40m
2026-07-02 N401NZ - Jul 2, 23:10 UTCJul 2, 23:45 UTC35m
2026-07-02 N401NZ - Jul 2, 19:20 UTCJul 2, 20:30 UTC1h 10m
2026-07-02 N401NZ - Jul 2, 00:05 UTCJul 2, 00:40 UTC35m
2026-07-01 N401NZ - Jul 1, 19:30 UTCJul 1, 20:15 UTC45m
2026-06-30 N401NZ - Jun 30, 23:35 UTCJul 1, 00:15 UTC40m
2026-06-30 N401NZ - Jun 30, 19:05 UTCJun 30, 19:45 UTC40m
2026-06-29 N401NZ - Jun 29, 01:05 UTCJun 29, 01:44 UTC40m
2026-06-27 N401NZ - Jun 27, 22:40 UTCJun 27, 23:39 UTC1h 0m
2026-06-27 N401NZ - Jun 27, 19:05 UTCJun 27, 19:34 UTC30m
2026-06-27 N401NZ - Jun 27, 01:59 UTCJun 27, 02:25 UTC25m
2026-06-27 N401NZ - Jun 27, 01:00 UTCJun 27, 01:24 UTC25m
2026-06-26 N401NZ - Jun 26, 20:10 UTCJun 26, 20:44 UTC35m
2026-06-26 N401NZ - Jun 26, 19:20 UTCJun 26, 19:39 UTC20m
2026-06-25 N401NZ - Jun 25, 01:59 UTCJun 25, 02:25 UTC25m
2026-06-24 N401NZ - Jun 24, 22:04 UTCJun 24, 22:29 UTC25m
2026-06-23 N401NZ - Jun 23, 23:59 UTCJun 24, 00:09 UTC10m
2026-06-23 N401NZ - Jun 23, 01:40 UTCJun 23, 02:55 UTC1h 15m
2026-06-21 N401NZ - Jun 21, 22:29 UTCJun 21, 23:24 UTC55m
2026-06-21 N401NZ - Jun 21, 16:10 UTCJun 21, 16:59 UTC50m
2026-06-19 N401NZ - Jun 19, 23:44 UTCJun 20, 00:24 UTC40m
2026-06-19 N401NZ - Jun 19, 19:04 UTCJun 19, 19:34 UTC30m
2026-06-19 N401NZ - Jun 19, 00:49 UTCJun 19, 00:55 UTC5m

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 N401NZ page for operator, model, and routing details .

Mode-S A4B19C frequently asked

What is Mode-S code A4B19C?
A4B19C is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N401NZ.
Where is Mode-S A4B19C registered?
Mode-S code A4B19C 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 A4B19C broadcasting right now?
No active broadcast right now. Last signal was 8h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A4B19C, octal 51130634, decimal 10,793,372.
What flights does A4B19C operate?
Mode-S A4B19C has broadcast 1 distinct callsign, including N401NZ.