sensors Mode-S transponder

3DDC74

ICAO 24-bit transponder address · allocated to Germany

Currently assigned to D-HDSU · AIRBUS HELICOPTERS EC-145

Hex
3DDC74
Octal
17356164
Decimal
4,054,132
Country
DE
Tail
D-HDSU
Type
EC45
No current signal · last broadcast 13h ago
Flights observed
6
Distinct callsigns
1
Country
DE
Last broadcast
13h ago

Last known position

Most recent position reported by Mode-S 3DDC74.

Country allocation

The ICAO 24-bit address 3DDC74 falls within the block assigned to Germany (DE) by ICAO Annex 10, Volume III. Every aircraft registered in Germany 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
CHX84 - 6 2026-04-14

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-14 CHX84 - Apr 14, 09:10 UTCApr 14, 09:30 UTC20m
2026-04-13 CHX84 - Apr 13, 23:35 UTCApr 13, 23:45 UTC10m
2026-04-13 CHX84 - Apr 13, 20:50 UTCApr 13, 21:35 UTC45m
2026-04-13 CHX84 - Apr 13, 18:25 UTCApr 13, 19:25 UTC1h 0m
2026-04-13 CHX84 - Apr 13, 12:30 UTCApr 13, 12:55 UTC25m
2026-04-13 CHX84 - Apr 13, 11:10 UTCApr 13, 11:30 UTC20m

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 D-HDSU page for operator, model, and routing details .

Mode-S 3DDC74 frequently asked

What is Mode-S code 3DDC74?
3DDC74 is an ICAO 24-bit transponder address. Allocated to Germany. Assigned to D-HDSU.
Where is Mode-S 3DDC74 registered?
Mode-S code 3DDC74 is allocated to Germany (DE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 3DDC74 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 3DDC74, octal 17356164, decimal 4,054,132.
What flights does 3DDC74 operate?
Mode-S 3DDC74 has broadcast 1 distinct callsign, including CHX84.