sensors Mode-S transponder

458AA4

ICAO 24-bit transponder address · allocated to Denmark

Currently assigned to OY-BUD · CESSNA 201 Centurion

Hex
458AA4
Octal
21305244
Decimal
4,557,476
Country
DK
Tail
OY-BUD
Type
C210
No current signal · last broadcast 1d ago
Flights observed
2
Distinct callsigns
1
Country
DK
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 458AA4.

Country allocation

The ICAO 24-bit address 458AA4 falls within the block assigned to Denmark (DK) by ICAO Annex 10, Volume III. Every aircraft registered in Denmark 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
OYBUD - 2 2026-04-13

Recent flights last 2

DateFlightRouteTakeoffLandingDuration
2026-04-13 OYBUD - Apr 13, 18:35 UTCApr 13, 19:00 UTC25m
2026-04-13 OYBUD - Apr 13, 15:45 UTCApr 13, 16:10 UTC25m

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 OY-BUD page for operator, model, and routing details .

Mode-S 458AA4 frequently asked

What is Mode-S code 458AA4?
458AA4 is an ICAO 24-bit transponder address. Allocated to Denmark. Assigned to OY-BUD.
Where is Mode-S 458AA4 registered?
Mode-S code 458AA4 is allocated to Denmark (DK). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 458AA4 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 458AA4, octal 21305244, decimal 4,557,476.
What flights does 458AA4 operate?
Mode-S 458AA4 has broadcast 1 distinct callsign, including OYBUD.