sensors Mode-S transponder

3D291B

ICAO 24-bit transponder address · allocated to Germany

Currently assigned to D-ENUX · DIAMOND DA-40 Club Star

Hex
3D291B
Octal
17224433
Decimal
4,008,219
Country
DE
Tail
D-ENUX
Type
DA40
Broadcasting now · callsign DENUX · 3,175 ft
Flights observed
7
Distinct callsigns
1
Country
DE
Last broadcast
2h ago

Current position

3D291B is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 3D291B 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
DENUX - 7 2026-04-18

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-18 DENUX - Apr 18, 14:05 UTCApr 18, 15:10 UTC1h 5m
2026-04-17 DENUX - Apr 17, 13:20 UTCApr 17, 14:00 UTC40m
2026-04-16 DENUX - Apr 16, 13:15 UTCApr 16, 13:40 UTC25m
2026-04-16 DENUX - Apr 16, 12:00 UTCApr 16, 13:05 UTC1h 5m
2026-04-16 DENUX - Apr 16, 09:29 UTCApr 16, 10:54 UTC1h 25m
2026-04-13 DENUX - Apr 13, 15:50 UTCApr 13, 16:10 UTC20m
2026-04-13 DENUX NUE → NUE Apr 13, 14:35 UTCApr 13, 16:10 UTC1h 35m

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

Mode-S 3D291B frequently asked

What is Mode-S code 3D291B?
3D291B is an ICAO 24-bit transponder address. Allocated to Germany. Assigned to D-ENUX.
Where is Mode-S 3D291B registered?
Mode-S code 3D291B is allocated to Germany (DE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 3D291B broadcasting right now?
Yes. Mode-S 3D291B is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 3D291B, octal 17224433, decimal 4,008,219.
What flights does 3D291B operate?
Mode-S 3D291B has broadcast 1 distinct callsign, including DENUX.