sensors Mode-S transponder

408329

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-TUPF · BOEING 737 MAX 8

Hex
408329
Octal
20101451
Decimal
4,227,881
Country
GB
Tail
G-TUPF
Type
B38M
Broadcasting now · callsign TOM607 · 38,000 ft
Flights observed
8
Distinct callsigns
3
Country
GB
Last broadcast
13h ago

Current position

408329 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 408329 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 3 distinct

Callsign Airline Flights Last seen
TOM753 - 3 2026-04-13
TOM626 - 3 2026-04-14
TOM752 TUI Airways 2 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-14 TOM626 - Apr 14, 09:10 UTCApr 14, 10:10 UTC1h 0m
2026-04-14 TOM626 - Apr 14, 07:10 UTCApr 14, 09:05 UTC1h 55m
2026-04-14 TOM626 - Apr 14, 06:45 UTCApr 14, 07:10 UTC25m
2026-04-13 TOM753 - Apr 13, 19:50 UTCApr 13, 21:45 UTC1h 55m
2026-04-13 TOM753 - Apr 13, 16:15 UTCApr 13, 20:10 UTC3h 55m
2026-04-13 TOM753 - Apr 13, 15:55 UTCApr 13, 16:15 UTC20m
2026-04-13 TOM752 LGW → DSS Apr 13, 13:35 UTCApr 13, 14:05 UTC30m
2026-04-13 TOM752 LGW → DSS Apr 13, 08:50 UTCApr 13, 11:10 UTC2h 20m

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

Mode-S 408329 frequently asked

What is Mode-S code 408329?
408329 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-TUPF.
Where is Mode-S 408329 registered?
Mode-S code 408329 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 408329 broadcasting right now?
Yes. Mode-S 408329 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 408329, octal 20101451, decimal 4,227,881.
What flights does 408329 operate?
Mode-S 408329 has broadcast 3 distinct callsigns, including TOM753, TOM626, TOM752.