sensors Mode-S transponder

45F45E

ICAO 24-bit transponder address · allocated to Denmark

Hex
45F45E
Octal
21372136
Decimal
4,584,542
Country
DK
No current signal · last broadcast 3d ago
Flights observed
2
Distinct callsigns
2
Country
DK
Last broadcast
3d ago

Last known position

Most recent position reported by Mode-S 45F45E.

Country allocation

The ICAO 24-bit address 45F45E 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 2 distinct

Callsign Airline Flights Last seen
PR21 - 1 2026-04-15
BB24 - 1 2026-04-13

Recent flights last 2

DateFlightRouteTakeoffLandingDuration
2026-04-15 PR21 - Apr 15, 09:30 UTCApr 15, 10:00 UTC30m
2026-04-13 BB24 - Apr 13, 11:05 UTCApr 13, 11:40 UTC35m

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.

Mode-S 45F45E frequently asked

What is Mode-S code 45F45E?
45F45E is an ICAO 24-bit transponder address. Allocated to Denmark.
Where is Mode-S 45F45E registered?
Mode-S code 45F45E is allocated to Denmark (DK). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 45F45E broadcasting right now?
No active broadcast right now. Last signal was 3d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 45F45E, octal 21372136, decimal 4,584,542.
What flights does 45F45E operate?
Mode-S 45F45E has broadcast 2 distinct callsigns, including PR21, BB24.