sensors Mode-S transponder

406B12

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-TUIE · BOEING 787-8 Dreamliner

Hex
406B12
Octal
20065422
Decimal
4,221,714
Country
GB
Tail
G-TUIE
Type
B788
No current signal
Flights observed
0
Distinct callsigns
20
Country
GB
Last broadcast
-

Country allocation

The ICAO 24-bit address 406B12 falls within the block assigned to United Kingdom (GB) by ICAO Annex 10, Volume III. Every aircraft registered in United Kingdom 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 20 distinct

Callsign Airline Flights Last seen
TOM115 - 8 2026-07-13
TOM193 TUI Airways 7 2026-06-29
TOM524 TUI Airways 6 2026-07-03
TOM754 TUI Airways 5 2026-07-04
TOM192 - 5 2026-07-13
TOM109 - 5 2026-07-02
TOM108 - 5 2026-07-02
TOM97D TUI Airways 4 2026-07-06
TOM9189 - 4 2026-07-03
TOM8YD TUI Airways 4 2026-07-06
TOM8LK TUI Airways 4 2026-07-05
TOM755 - 4 2026-07-04
TOM684 TUI Airways 4 2026-07-08
TOM56M TUI Airways 4 2026-07-05
TOM4DX TUI Airways 4 2026-07-05
TOM246 - 4 2026-04-13
TOM9849 - 3 2026-06-17
TOM9621 - 3 2026-07-12
TOM84Y - 3 2026-07-06
TOM849 TUI Airways 3 2026-06-16

Recent flights

No flights recorded yet for this transponder.

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 G-TUIE page for operator, model, and routing details .

Mode-S 406B12 frequently asked

What is Mode-S code 406B12?
406B12 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-TUIE.
Where is Mode-S 406B12 registered?
Mode-S code 406B12 is allocated to United Kingdom (GB). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 406B12 broadcasting right now?
No active broadcast right now.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 406B12, octal 20065422, decimal 4,221,714.
What flights does 406B12 operate?
Mode-S 406B12 has broadcast 20 distinct callsigns, including TOM115, TOM193, TOM524, TOM754, TOM192.