Apparatus

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sensors Mode-S transponder

4401D4

ICAO 24-bit transponder address · allocated to Austria

Currently assigned to OE-GTA · EMBRAER EMB-505 Phenom 300

Hex
4401D4
Octal
21000724
Decimal
4,456,916
Country
AT
Tail
OE-GTA
Type
E55P
No current signal · last broadcast 1d ago
Flights observed
8
Distinct callsigns
1
Country
AT
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 4401D4.

Country allocation

The ICAO 24-bit address 4401D4 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
BOM1 - 8 2026-04-14

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-14 BOM1 - Apr 14, 05:15 UTCApr 14, 05:25 UTC10m
2026-04-13 BOM1 - Apr 13, 16:15 UTCApr 13, 16:45 UTC30m
2026-04-13 BOM1 - Apr 13, 15:50 UTCApr 13, 16:45 UTC55m
2026-04-13 BOM1 - Apr 13, 15:40 UTCApr 13, 16:15 UTC35m
2026-04-13 BOM1 ZRH → CIA Apr 13, 13:45 UTCApr 13, 14:55 UTC1h 10m
2026-04-13 BOM1 - Apr 13, 12:20 UTCApr 13, 12:30 UTC10m
2026-04-13 BOM1 - Apr 13, 11:55 UTCApr 13, 12:30 UTC35m
2026-04-13 BOM1 - Apr 13, 11:10 UTCApr 13, 12:15 UTC1h 5m

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

Mode-S 4401D4 frequently asked

What is Mode-S code 4401D4?
4401D4 is an ICAO 24-bit transponder address. Allocated to Austria. Assigned to OE-GTA.
Where is Mode-S 4401D4 registered?
Mode-S code 4401D4 is allocated to Austria (AT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4401D4 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 4401D4, octal 21000724, decimal 4,456,916.
What flights does 4401D4 operate?
Mode-S 4401D4 has broadcast 1 distinct callsign, including BOM1.