Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

3C7421

ICAO 24-bit transponder address · allocated to Germany

Currently assigned to D-AMAA · BOEING 737 MAX 8

Hex
3C7421
Octal
17072041
Decimal
3,961,889
Country
DE
Tail
D-AMAA
Type
B38M
Broadcasting now · callsign TUI9PE · 38,000 ft
Flights observed
11
Distinct callsigns
6
Country
DE
Last broadcast
22h ago

Current position

3C7421 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 3C7421 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 6 distinct

Callsign Airline Flights Last seen
TUI3GA - 3 2026-04-13
TUI1A - 3 2026-04-14
TUI7CX TUIfly 2 2026-04-13
TUI98Y - 1 2026-04-13
TUI75D - 1 2026-04-12
TUI6NL - 1 2026-04-13

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 TUI1A - Apr 14, 09:10 UTCApr 14, 10:25 UTC1h 15m
2026-04-14 TUI1A - Apr 14, 07:10 UTCApr 14, 09:05 UTC1h 55m
2026-04-14 TUI1A - Apr 14, 06:35 UTCApr 14, 07:10 UTC35m
2026-04-13 TUI3GA - Apr 13, 19:50 UTCApr 13, 23:00 UTC3h 10m
2026-04-13 TUI3GA - Apr 13, 16:35 UTCApr 13, 20:10 UTC3h 35m
2026-04-13 TUI3GA - Apr 13, 15:50 UTCApr 13, 19:45 UTC3h 55m
2026-04-13 TUI6NL - Apr 13, 12:55 UTCApr 13, 15:55 UTC3h 0m
2026-04-13 TUI98Y - Apr 13, 08:20 UTCApr 13, 11:15 UTC2h 55m
2026-04-13 TUI7CX HAJ → HER Apr 13, 04:20 UTCApr 13, 07:00 UTC2h 40m
2026-04-13 TUI7CX HAJ → HER Apr 13, 04:10 UTCApr 13, 04:15 UTC5m
2026-04-12 TUI75D - Apr 12, 17:15 UTCApr 12, 20:15 UTC3h 0m

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

Mode-S 3C7421 frequently asked

What is Mode-S code 3C7421?
3C7421 is an ICAO 24-bit transponder address. Allocated to Germany. Assigned to D-AMAA.
Where is Mode-S 3C7421 registered?
Mode-S code 3C7421 is allocated to Germany (DE). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 3C7421 broadcasting right now?
Yes. Mode-S 3C7421 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 3C7421, octal 17072041, decimal 3,961,889.
What flights does 3C7421 operate?
Mode-S 3C7421 has broadcast 6 distinct callsigns, including TUI3GA, TUI1A, TUI7CX, TUI98Y, TUI75D.