sensors Mode-S transponder

3D21E6

ICAO 24-bit transponder address · allocated to Germany

Currently assigned to D-ELBY · SOCATA Rallye

Hex
3D21E6
Octal
17220746
Decimal
4,006,374
Country
DE
Tail
D-ELBY
Type
RALL
No current signal · last broadcast 7h ago
Flights observed
32
Distinct callsigns
1
Country
DE
Last broadcast
7h ago

Last known position

Most recent position reported by Mode-S 3D21E6.

Country allocation

The ICAO 24-bit address 3D21E6 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
DELBY - 32 2026-06-02

Recent flights last 32

DateFlightRouteTakeoffLandingDuration
2026-06-02 DELBY - Jun 2, 11:05 UTCJun 2, 12:25 UTC1h 20m
2026-06-01 DELBY - Jun 1, 09:05 UTCJun 1, 10:35 UTC1h 30m
2026-05-30 DELBY - May 30, 08:25 UTCMay 30, 10:30 UTC2h 5m
2026-05-27 DELBY - May 27, 09:35 UTCMay 27, 12:10 UTC2h 35m
2026-05-25 DELBY - May 25, 11:40 UTCMay 25, 13:10 UTC1h 30m
2026-05-23 DELBY - May 23, 10:10 UTCMay 23, 11:40 UTC1h 30m
2026-05-17 DELBY - May 17, 14:30 UTCMay 17, 14:50 UTC20m
2026-05-17 DELBY - May 17, 13:15 UTCMay 17, 13:40 UTC25m
2026-05-16 DELBY - May 16, 16:00 UTCMay 16, 16:15 UTC15m
2026-05-16 DELBY - May 16, 14:20 UTCMay 16, 14:41 UTC20m
2026-05-09 DELBY - May 9, 15:55 UTCMay 9, 16:55 UTC1h 0m
2026-05-09 DELBY - May 9, 09:40 UTCMay 9, 10:35 UTC55m
2026-05-09 DELBY - May 9, 07:40 UTCMay 9, 07:55 UTC15m
2026-05-08 DELBY - May 8, 11:09 UTCMay 8, 11:55 UTC45m
2026-05-07 DELBY - May 7, 14:00 UTCMay 7, 14:40 UTC40m
2026-05-03 DELBY - May 3, 10:30 UTCMay 3, 11:50 UTC1h 20m
2026-05-01 DELBY - May 1, 06:50 UTCMay 1, 08:30 UTC1h 40m
2026-04-28 DELBY - Apr 28, 16:05 UTCApr 28, 16:25 UTC20m
2026-04-26 DELBY - Apr 26, 14:05 UTCApr 26, 15:20 UTC1h 15m
2026-04-25 DELBY - Apr 25, 07:00 UTCApr 25, 08:15 UTC1h 15m
2026-04-23 DELBY - Apr 23, 16:00 UTCApr 23, 17:25 UTC1h 25m
2026-04-23 DELBY - Apr 23, 06:25 UTCApr 23, 07:50 UTC1h 25m
2026-04-19 DELBY - Apr 19, 09:00 UTCApr 19, 09:15 UTC15m
2026-04-19 DELBY - Apr 19, 08:25 UTCApr 19, 08:45 UTC20m
2026-04-17 DELBY - Apr 17, 15:20 UTCApr 17, 15:30 UTC10m
2026-04-17 DELBY - Apr 17, 14:20 UTCApr 17, 15:15 UTC54m
2026-04-17 DELBY - Apr 17, 08:05 UTCApr 17, 09:15 UTC1h 10m
2026-04-16 DELBY - Apr 16, 17:15 UTCApr 16, 18:40 UTC1h 25m
2026-04-16 DELBY - Apr 16, 15:30 UTCApr 16, 17:10 UTC1h 40m
2026-04-15 DELBY - Apr 15, 13:01 UTCApr 15, 14:55 UTC1h 54m
2026-04-15 DELBY - Apr 15, 12:01 UTCApr 15, 12:55 UTC55m
2026-04-14 DELBY - Apr 14, 14:50 UTCApr 14, 15:15 UTC25m

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

Mode-S 3D21E6 frequently asked

What is Mode-S code 3D21E6?
3D21E6 is an ICAO 24-bit transponder address. Allocated to Germany. Assigned to D-ELBY.
Where is Mode-S 3D21E6 registered?
Mode-S code 3D21E6 is allocated to Germany (DE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 3D21E6 broadcasting right now?
No active broadcast right now. Last signal was 7h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 3D21E6, octal 17220746, decimal 4,006,374.
What flights does 3D21E6 operate?
Mode-S 3D21E6 has broadcast 1 distinct callsign, including DELBY.