sensors Mode-S transponder

3E557D

ICAO 24-bit transponder address · allocated to Germany

Currently assigned to D-IXON · CESSNA 525 Citation M2

Hex
3E557D
Octal
17452575
Decimal
4,085,117
Country
DE
Tail
D-IXON
Type
C25M
No current signal · last broadcast 1d ago
Flights observed
1
Distinct callsigns
1
Country
DE
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 3E557D.

Country allocation

The ICAO 24-bit address 3E557D 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
FSE1D - 1 2026-04-13

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-04-13 FSE1D ZRH → DUS Apr 13, 07:05 UTCApr 13, 08:00 UTC55m

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

Mode-S 3E557D frequently asked

What is Mode-S code 3E557D?
3E557D is an ICAO 24-bit transponder address. Allocated to Germany. Assigned to D-IXON.
Where is Mode-S 3E557D registered?
Mode-S code 3E557D is allocated to Germany (DE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 3E557D 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 3E557D, octal 17452575, decimal 4,085,117.
What flights does 3E557D operate?
Mode-S 3E557D has broadcast 1 distinct callsign, including FSE1D.