sensors Mode-S transponder

440521

ICAO 24-bit transponder address · allocated to Austria

Currently assigned to OE-COG · DIAMOND DA-20

Hex
440521
Octal
21002441
Decimal
4,457,761
Country
AT
Tail
OE-COG
Type
DV20
No current signal · last broadcast 2d ago
Flights observed
10
Distinct callsigns
1
Country
AT
Last broadcast
2d ago

Last known position

Most recent position reported by Mode-S 440521.

Country allocation

The ICAO 24-bit address 440521 falls within the block assigned to Austria (AT) by ICAO Annex 10, Volume III. Every aircraft registered in Austria 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
OECOG - 10 2026-04-16

Recent flights last 10

DateFlightRouteTakeoffLandingDuration
2026-04-16 OECOG - Apr 16, 15:15 UTCApr 16, 15:25 UTC10m
2026-04-16 OECOG - Apr 16, 14:05 UTCApr 16, 15:10 UTC1h 5m
2026-04-15 OECOG - Apr 15, 13:01 UTCApr 15, 14:55 UTC1h 54m
2026-04-15 OECOG - Apr 15, 09:00 UTCApr 15, 09:30 UTC30m
2026-04-15 OECOG - Apr 15, 08:25 UTCApr 15, 08:55 UTC30m
2026-04-14 OECOG - Apr 14, 15:10 UTCApr 14, 16:10 UTC1h 0m
2026-04-14 OECOG - Apr 14, 12:50 UTCApr 14, 13:20 UTC30m
2026-04-14 OECOG - Apr 14, 12:20 UTCApr 14, 12:45 UTC25m
2026-04-14 OECOG - Apr 14, 08:40 UTCApr 14, 09:05 UTC25m
2026-04-13 OECOG - Apr 13, 08:40 UTCApr 13, 09:35 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 OE-COG page for operator, model, and routing details .

Mode-S 440521 frequently asked

What is Mode-S code 440521?
440521 is an ICAO 24-bit transponder address. Allocated to Austria. Assigned to OE-COG.
Where is Mode-S 440521 registered?
Mode-S code 440521 is allocated to Austria (AT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 440521 broadcasting right now?
No active broadcast right now. Last signal was 2d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 440521, octal 21002441, decimal 4,457,761.
What flights does 440521 operate?
Mode-S 440521 has broadcast 1 distinct callsign, including OECOG.