sensors Mode-S transponder

459A65

ICAO 24-bit transponder address · allocated to Denmark

Currently assigned to OY-FSE · SAAB 2000

Hex
459A65
Octal
21315145
Decimal
4,561,509
Country
DK
Tail
OY-FSE
Type
SB20
No current signal · last broadcast 13h ago
Flights observed
16
Distinct callsigns
8
Country
DK
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S 459A65.

Country allocation

The ICAO 24-bit address 459A65 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 8 distinct

Callsign Airline Flights Last seen
FRO684 - 3 2026-04-13
FRO674 - 3 2026-04-14
FRO685 - 2 2026-04-13
FRO675 - 2 2026-04-14
FRO671 - 2 2026-04-14
FRO670 - 2 2026-04-14
FRO679 - 1 2026-04-13
FRO678 - 1 2026-04-13

Recent flights last 16

DateFlightRouteTakeoffLandingDuration
2026-04-14 FRO675 - Apr 14, 09:20 UTCApr 14, 10:20 UTC1h 0m
2026-04-14 FRO674 - Apr 14, 07:55 UTCApr 14, 08:50 UTC55m
2026-04-14 FRO671 - Apr 14, 06:15 UTCApr 14, 07:10 UTC55m
2026-04-14 FRO670 - Apr 14, 05:15 UTCApr 14, 05:45 UTC30m
2026-04-13 FRO685 BMA → MMX Apr 13, 16:55 UTCApr 13, 17:55 UTC1h 0m
2026-04-13 FRO684 - Apr 13, 16:15 UTCApr 13, 16:25 UTC10m
2026-04-13 FRO684 - Apr 13, 15:50 UTCApr 13, 16:25 UTC35m
2026-04-13 FRO684 - Apr 13, 15:30 UTCApr 13, 16:15 UTC45m
2026-04-13 FRO679 - Apr 13, 14:00 UTCApr 13, 14:55 UTC55m
2026-04-13 FRO678 - Apr 13, 12:30 UTCApr 13, 13:25 UTC55m
2026-04-13 FRO675 BMA → MMX Apr 13, 09:30 UTCApr 13, 10:25 UTC55m
2026-04-13 FRO674 - Apr 13, 08:20 UTCApr 13, 08:50 UTC30m
2026-04-13 FRO674 - Apr 13, 07:55 UTCApr 13, 08:15 UTC20m
2026-04-13 FRO671 - Apr 13, 06:15 UTCApr 13, 07:10 UTC55m
2026-04-13 FRO670 - Apr 13, 04:50 UTCApr 13, 05:40 UTC50m
2026-04-12 FRO685 - Apr 12, 17:15 UTCApr 12, 17:55 UTC40m

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-FSE page for operator, model, and routing details .

Mode-S 459A65 frequently asked

What is Mode-S code 459A65?
459A65 is an ICAO 24-bit transponder address. Allocated to Denmark. Assigned to OY-FSE.
Where is Mode-S 459A65 registered?
Mode-S code 459A65 is allocated to Denmark (DK). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 459A65 broadcasting right now?
No active broadcast right now. Last signal was 13h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 459A65, octal 21315145, decimal 4,561,509.
What flights does 459A65 operate?
Mode-S 459A65 has broadcast 8 distinct callsigns, including FRO684, FRO674, FRO685, FRO675, FRO671.