Apparatus

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sensors Mode-S transponder

4403DD

ICAO 24-bit transponder address · allocated to Austria

Currently assigned to OE-XXR · AIRBUS HELICOPTERS EC-135/635

Hex
4403DD
Octal
21001735
Decimal
4,457,437
Country
AT
Tail
OE-XXR
Type
EC35
No current signal · last broadcast 2d ago
Flights observed
114
Distinct callsigns
2
Country
AT
Last broadcast
2d ago

Last known position

Most recent position reported by Mode-S 4403DD.

Country allocation

The ICAO 24-bit address 4403DD 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 2 distinct

Callsign Airline Flights Last seen
HELI3 - 113 2026-06-06
HELIX - 1 2026-04-23

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-06-06 HELI3 - Jun 6, 11:30 UTCJun 6, 12:24 UTC55m
2026-06-06 HELI3 - Jun 6, 08:35 UTCJun 6, 09:15 UTC40m
2026-06-06 HELI3 - Jun 6, 05:25 UTCJun 6, 06:00 UTC35m
2026-06-05 HELI3 - Jun 5, 09:45 UTCJun 5, 10:45 UTC1h 0m
2026-06-04 HELI3 - Jun 4, 11:20 UTCJun 4, 12:20 UTC1h 0m
2026-06-04 HELI3 - Jun 4, 10:35 UTCJun 4, 10:40 UTC5m
2026-06-04 HELI3 - Jun 4, 10:05 UTCJun 4, 10:10 UTC5m
2026-06-04 HELI3 - Jun 4, 08:10 UTCJun 4, 09:40 UTC1h 30m
2026-06-03 HELI3 - Jun 3, 12:40 UTCJun 3, 13:20 UTC40m
2026-06-03 HELI3 - Jun 3, 11:45 UTCJun 3, 11:55 UTC10m
2026-06-01 HELI3 - Jun 1, 20:05 UTCJun 1, 20:45 UTC40m
2026-06-01 HELI3 - Jun 1, 18:30 UTCJun 1, 18:45 UTC15m
2026-06-01 HELI3 - Jun 1, 18:10 UTCJun 1, 18:15 UTC5m
2026-06-01 HELI3 - Jun 1, 16:35 UTCJun 1, 17:15 UTC40m
2026-06-01 HELI3 - Jun 1, 13:10 UTCJun 1, 14:45 UTC1h 35m
2026-06-01 HELI3 - Jun 1, 11:25 UTCJun 1, 11:45 UTC20m
2026-05-31 HELI3 - May 31, 18:10 UTCMay 31, 19:10 UTC1h 0m
2026-05-31 HELI3 - May 31, 09:10 UTCMay 31, 09:15 UTC5m
2026-05-31 HELI3 - May 31, 08:50 UTCMay 31, 09:05 UTC15m
2026-05-31 HELI3 - May 31, 08:25 UTCMay 31, 08:40 UTC15m
2026-05-30 HELI3 - May 30, 14:40 UTCMay 30, 14:50 UTC10m
2026-05-30 HELI3 - May 30, 05:05 UTCMay 30, 06:20 UTC1h 15m
2026-05-29 HELI3 - May 29, 19:20 UTCMay 29, 20:00 UTC40m
2026-05-29 HELI3 - May 29, 16:55 UTCMay 29, 18:00 UTC1h 5m
2026-05-29 HELI3 - May 29, 16:00 UTCMay 29, 16:25 UTC25m
2026-05-29 HELI3 - May 29, 15:20 UTCMay 29, 15:35 UTC15m
2026-05-29 HELI3 - May 29, 12:20 UTCMay 29, 13:45 UTC1h 25m
2026-05-29 HELI3 - May 29, 07:25 UTCMay 29, 08:00 UTC35m
2026-05-28 HELI3 - May 28, 20:35 UTCMay 28, 21:00 UTC25m
2026-05-28 HELI3 - May 28, 19:10 UTCMay 28, 20:05 UTC55m
2026-05-27 HELI3 - May 27, 19:55 UTCMay 27, 20:10 UTC15m
2026-05-27 HELI3 - May 27, 10:55 UTCMay 27, 11:40 UTC45m
2026-05-27 HELI3 - May 27, 09:40 UTCMay 27, 10:05 UTC25m
2026-05-25 HELI3 - May 25, 11:30 UTCMay 25, 12:40 UTC1h 10m
2026-05-24 HELI3 - May 24, 13:05 UTCMay 24, 13:25 UTC20m
2026-05-24 HELI3 - May 24, 12:25 UTCMay 24, 12:35 UTC10m
2026-05-24 HELI3 - May 24, 10:15 UTCMay 24, 10:55 UTC40m
2026-05-23 HELI3 - May 23, 17:00 UTCMay 23, 17:20 UTC20m
2026-05-23 HELI3 - May 23, 16:10 UTCMay 23, 16:20 UTC10m
2026-05-23 HELI3 - May 23, 15:15 UTCMay 23, 15:20 UTC5m
2026-05-23 HELI3 - May 23, 10:15 UTCMay 23, 10:25 UTC10m
2026-05-23 HELI3 - May 23, 06:35 UTCMay 23, 06:55 UTC20m
2026-05-23 HELI3 - May 23, 06:10 UTCMay 23, 06:30 UTC20m
2026-05-22 HELI3 - May 22, 16:00 UTCMay 22, 16:20 UTC20m
2026-05-22 HELI3 - May 22, 15:10 UTCMay 22, 15:20 UTC10m
2026-05-22 HELI3 - May 22, 13:55 UTCMay 22, 14:05 UTC10m
2026-05-22 HELI3 - May 22, 10:10 UTCMay 22, 11:20 UTC1h 10m
2026-05-21 HELI3 - May 21, 17:30 UTCMay 21, 18:10 UTC40m
2026-05-21 HELI3 - May 21, 10:55 UTCMay 21, 11:40 UTC45m
2026-05-21 HELI3 - May 21, 10:25 UTCMay 21, 10:30 UTC5m

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

Mode-S 4403DD frequently asked

What is Mode-S code 4403DD?
4403DD is an ICAO 24-bit transponder address. Allocated to Austria. Assigned to OE-XXR.
Where is Mode-S 4403DD registered?
Mode-S code 4403DD is allocated to Austria (AT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4403DD 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 4403DD, octal 21001735, decimal 4,457,437.
What flights does 4403DD operate?
Mode-S 4403DD has broadcast 2 distinct callsigns, including HELI3, HELIX.