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 22h ago
Flights observed
237
Distinct callsigns
2
Country
AT
Last broadcast
22h 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 - 236 2026-07-22
HELIX - 1 2026-04-23

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-22 HELI3 - Jul 22, 20:15 UTCJul 22, 20:35 UTC20m
2026-07-22 HELI3 - Jul 22, 19:25 UTCJul 22, 19:45 UTC20m
2026-07-22 HELI3 - Jul 22, 15:00 UTCJul 22, 16:00 UTC1h 0m
2026-07-22 HELI3 - Jul 22, 11:35 UTCJul 22, 12:15 UTC40m
2026-07-22 HELI3 - Jul 22, 11:10 UTCJul 22, 11:20 UTC10m
2026-07-20 HELI3 - Jul 20, 12:45 UTCJul 20, 13:00 UTC15m
2026-07-20 HELI3 - Jul 20, 05:40 UTCJul 20, 06:45 UTC1h 5m
2026-07-19 HELI3 - Jul 19, 18:40 UTCJul 19, 19:40 UTC1h 0m
2026-07-19 HELI3 - Jul 19, 16:55 UTCJul 19, 17:30 UTC35m
2026-07-19 HELI3 - Jul 19, 11:05 UTCJul 19, 11:30 UTC25m
2026-07-19 HELI3 - Jul 19, 10:10 UTCJul 19, 10:35 UTC25m
2026-07-18 HELI3 - Jul 18, 13:05 UTCJul 18, 13:45 UTC40m
2026-07-18 HELI3 - Jul 18, 08:20 UTCJul 18, 09:05 UTC45m
2026-07-18 HELI3 - Jul 18, 06:15 UTCJul 18, 06:40 UTC25m
2026-07-17 HELI3 - Jul 17, 14:10 UTCJul 17, 14:55 UTC45m
2026-07-17 HELI3 - Jul 17, 13:20 UTCJul 17, 13:35 UTC15m
2026-07-17 HELI3 - Jul 17, 12:30 UTCJul 17, 13:15 UTC45m
2026-07-17 HELI3 - Jul 17, 11:30 UTCJul 17, 11:45 UTC15m
2026-07-16 HELI3 - Jul 16, 17:45 UTCJul 16, 17:54 UTC10m
2026-07-16 HELI3 - Jul 16, 12:44 UTCJul 16, 13:15 UTC30m
2026-07-15 HELI3 - Jul 15, 15:25 UTCJul 15, 16:00 UTC35m
2026-07-15 HELI3 - Jul 15, 13:10 UTCJul 15, 14:15 UTC1h 5m
2026-07-14 HELI3 - Jul 14, 15:45 UTCJul 14, 16:10 UTC25m
2026-07-14 HELI3 - Jul 14, 14:05 UTCJul 14, 14:25 UTC20m
2026-07-14 HELI3 - Jul 14, 13:05 UTCJul 14, 13:45 UTC40m
2026-07-14 HELI3 - Jul 14, 12:10 UTCJul 14, 12:30 UTC20m
2026-07-14 HELI3 - Jul 14, 11:15 UTCJul 14, 11:35 UTC20m
2026-07-12 HELI3 - Jul 12, 17:25 UTCJul 12, 17:50 UTC25m
2026-07-12 HELI3 - Jul 12, 17:01 UTCJul 12, 17:20 UTC20m
2026-07-12 HELI3 - Jul 12, 15:35 UTCJul 12, 16:10 UTC35m
2026-07-12 HELI3 - Jul 12, 14:50 UTCJul 12, 15:01 UTC10m
2026-07-12 HELI3 - Jul 12, 11:10 UTCJul 12, 11:25 UTC15m
2026-07-12 HELI3 - Jul 12, 09:15 UTCJul 12, 09:25 UTC10m
2026-07-12 HELI3 - Jul 12, 08:15 UTCJul 12, 08:35 UTC20m
2026-07-12 HELI3 - Jul 12, 07:31 UTCJul 12, 08:10 UTC40m
2026-07-11 HELI3 - Jul 11, 18:35 UTCJul 11, 19:15 UTC40m
2026-07-11 HELI3 - Jul 11, 13:20 UTCJul 11, 13:50 UTC30m
2026-07-11 HELI3 - Jul 11, 12:55 UTCJul 11, 13:05 UTC10m
2026-07-11 HELI3 - Jul 11, 11:55 UTCJul 11, 12:35 UTC40m
2026-07-10 HELI3 - Jul 10, 19:40 UTCJul 10, 20:00 UTC20m
2026-07-10 HELI3 - Jul 10, 19:15 UTCJul 10, 19:35 UTC20m
2026-07-10 HELI3 - Jul 10, 15:30 UTCJul 10, 16:35 UTC1h 5m
2026-07-10 HELI3 - Jul 10, 13:00 UTCJul 10, 13:20 UTC20m
2026-07-10 HELI3 - Jul 10, 12:15 UTCJul 10, 12:55 UTC40m
2026-07-10 HELI3 - Jul 10, 09:20 UTCJul 10, 09:30 UTC10m
2026-07-10 HELI3 - Jul 10, 08:00 UTCJul 10, 08:35 UTC35m
2026-07-09 HELI3 - Jul 9, 17:25 UTCJul 9, 18:35 UTC1h 10m
2026-07-09 HELI3 - Jul 9, 16:00 UTCJul 9, 16:20 UTC20m
2026-07-09 HELI3 - Jul 9, 15:05 UTCJul 9, 15:45 UTC40m
2026-07-09 HELI3 - Jul 9, 13:05 UTCJul 9, 14:10 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-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 22h 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.