sensors Mode-S transponder

A23B55

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N243BZ · AIRBUS A220-100 · operated by BANK OF UTAH TRUSTEE

Hex
A23B55
Octal
50435525
Decimal
10,632,021
Country
US
Tail
N243BZ
Type
BCS1
Broadcasting now · callsign MXY9770 · 35,975 ft
Flights observed
7
Distinct callsigns
4
Country
US
Last broadcast
1d ago

Current position

A23B55 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address A23B55 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 4 distinct

Callsign Airline Flights Last seen
MXY585 - 3 2026-04-13
MXY581 - 2 2026-04-13
MXY584 - 1 2026-04-13
MXY580 Breeze Airways 1 2026-04-13

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-13 MXY580 VRB → HPN Apr 13, 20:10 UTCApr 13, 22:30 UTC2h 20m
2026-04-13 MXY585 - Apr 13, 16:15 UTCApr 13, 18:20 UTC2h 5m
2026-04-13 MXY585 - Apr 13, 16:05 UTCApr 13, 16:15 UTC10m
2026-04-13 MXY584 - Apr 13, 12:35 UTCApr 13, 14:45 UTC2h 10m
2026-04-13 MXY581 - Apr 13, 00:20 UTCApr 13, 02:00 UTC1h 40m
2026-04-13 MXY581 - Apr 13, 00:00 UTCApr 13, 02:00 UTC2h 0m
2026-04-12 MXY585 - Apr 12, 17:15 UTCApr 12, 18:10 UTC55m

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 N243BZ page for operator, model, and routing details .

Mode-S A23B55 frequently asked

What is Mode-S code A23B55?
A23B55 is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N243BZ.
Where is Mode-S A23B55 registered?
Mode-S code A23B55 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 A23B55 broadcasting right now?
Yes. Mode-S A23B55 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A23B55, octal 50435525, decimal 10,632,021.
What flights does A23B55 operate?
Mode-S A23B55 has broadcast 4 distinct callsigns, including MXY585, MXY581, MXY584, MXY580.