sensors Mode-S transponder

A275CF

ICAO 24-bit transponder address · allocated to United States

Currently assigned to N258GC · BOMBARDIER CL-600 Challenger

Hex
A275CF
Octal
50472717
Decimal
10,646,991
Country
US
Tail
N258GC
Type
CL60
No current signal · last broadcast 1d ago
Flights observed
6
Distinct callsigns
1
Country
US
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S A275CF.

Country allocation

The ICAO 24-bit address A275CF 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
EJM258 - 6 2026-04-13

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-13 EJM258 - Apr 13, 19:50 UTCApr 13, 21:10 UTC1h 20m
2026-04-13 EJM258 - Apr 13, 18:30 UTCApr 13, 20:10 UTC1h 40m
2026-04-13 EJM258 - Apr 13, 16:15 UTCApr 13, 17:45 UTC1h 30m
2026-04-13 EJM258 - Apr 13, 15:50 UTCApr 13, 17:45 UTC1h 55m
2026-04-13 EJM258 - Apr 13, 15:15 UTCApr 13, 16:15 UTC1h 0m
2026-04-12 EJM258 - Apr 12, 17:50 UTCApr 12, 20:15 UTC2h 25m

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 N258GC page for operator, model, and routing details .

Mode-S A275CF frequently asked

What is Mode-S code A275CF?
A275CF is an ICAO 24-bit transponder address. Allocated to United States. Assigned to N258GC.
Where is Mode-S A275CF registered?
Mode-S code A275CF 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 A275CF broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex A275CF, octal 50472717, decimal 10,646,991.
What flights does A275CF operate?
Mode-S A275CF has broadcast 1 distinct callsign, including EJM258.