sensors Mode-S transponder

400FF4

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-FDZD · BOEING 737-800

Hex
400FF4
Octal
20007764
Decimal
4,198,388
Country
GB
Tail
G-FDZD
Type
B738
Broadcasting now · callsign TOM30K · 37,000 ft
Flights observed
303
Distinct callsigns
20
Country
GB
Last broadcast
16m ago

Current position

400FF4 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 400FF4 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
TOM8KE TUI Airways 5 2026-07-04
TOM23G - 5 2026-07-04
TOM213 - 5 2026-07-11
TOM9TM - 4 2026-07-11
TOM86L TUI Airways 4 2026-07-07
TOM7WJ TUI Airways 4 2026-07-04
TOM7LN - 4 2026-07-11
TOM5XY - 4 2026-07-11
TOM5JK - 4 2026-06-30
TOM3WN - 4 2026-07-10
TOM2BA TUI Airways 4 2026-07-04
TOM9KY TUI Airways 3 2026-07-07
TOM9KN - 3 2026-07-10
TOM9BJ - 3 2026-04-13
TOM8VA TUI Airways 3 2026-07-07
TOM7XY TUI Airways 3 2026-06-08
TOM7AN TUI Airways 3 2026-06-08
TOM6NK - 3 2026-07-05
TOM5TN TUI Airways 3 2026-04-15
TOM536 TUI Airways 3 2026-07-07

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-15 TOM30K - Jul 15, 06:40 UTCJul 15, 09:00 UTC2h 20m
2026-07-14 TOM1MV - Jul 14, 19:10 UTCJul 14, 22:35 UTC3h 25m
2026-07-14 TOM9PY - Jul 14, 13:15 UTCJul 14, 17:35 UTC4h 20m
2026-07-14 TOM9XH - Jul 14, 09:05 UTCJul 14, 11:00 UTC1h 55m
2026-07-14 TOM8XE - Jul 14, 05:20 UTCJul 14, 07:25 UTC2h 5m
2026-07-13 TOM125 - Jul 13, 19:55 UTCJul 13, 22:50 UTC2h 55m
2026-07-13 TOM124 - Jul 13, 15:40 UTCJul 13, 18:20 UTC2h 40m
2026-07-13 TOM82K MAH → STN Jul 13, 09:10 UTCJul 13, 11:15 UTC2h 5m
2026-07-13 TOM51W MAN → MAH Jul 13, 05:35 UTCJul 13, 07:55 UTC2h 20m
2026-07-11 TOM213 - Jul 11, 21:25 UTCJul 12, 01:30 UTC4h 5m
2026-07-11 TOM5XY - Jul 11, 16:05 UTCJul 11, 19:55 UTC3h 50m
2026-07-11 TOM7LN IBZ → MAN Jul 11, 11:15 UTCJul 11, 13:30 UTC2h 15m
2026-07-11 TOM9TM MAN → IBZ Jul 11, 06:55 UTCJul 11, 09:25 UTC2h 30m
2026-07-10 TOM27A - Jul 10, 17:50 UTCJul 10, 20:50 UTC3h 0m
2026-07-10 TOM7YW - Jul 10, 13:20 UTCJul 10, 16:00 UTC2h 40m
2026-07-10 TOM9KN REU → MAN Jul 10, 09:50 UTCJul 10, 11:50 UTC2h 0m
2026-07-10 TOM3WN - Jul 10, 06:50 UTCJul 10, 08:40 UTC1h 50m
2026-07-09 TOM8HB MAN → MAN Jul 9, 18:45 UTCJul 10, 02:45 UTC8h 0m
2026-07-09 TOM1JV - Jul 9, 12:05 UTCJul 9, 17:10 UTC5h 5m
2026-07-09 TOM5DV - Jul 9, 06:15 UTCJul 9, 10:25 UTC4h 10m
2026-07-08 TOM6KC - Jul 8, 22:35 UTCJul 9, 03:25 UTC4h 50m
2026-07-08 TOM2TN - Jul 8, 16:50 UTCJul 8, 21:00 UTC4h 10m
2026-07-08 TOM2TB - Jul 8, 11:35 UTCJul 8, 13:25 UTC1h 50m
2026-07-08 TOM5PG MAN → SZG Jul 8, 08:10 UTCJul 8, 09:55 UTC1h 45m
2026-07-07 TOM8VA EFL → MAN Jul 7, 21:55 UTCJul 8, 01:10 UTC3h 15m
2026-07-07 TOM536 MAN → RAK Jul 7, 17:10 UTCJul 7, 20:10 UTC3h 0m
2026-07-07 TOM86L BVC → BHX Jul 7, 11:30 UTCJul 7, 15:10 UTC3h 40m
2026-07-07 TOM9KY INN → BHX Jul 7, 06:35 UTCJul 7, 09:40 UTC3h 5m
2026-07-06 TOM451 MAN → MAN Jul 6, 14:25 UTCJul 7, 02:50 UTC12h 25m
2026-07-06 TOM55H - Jul 6, 10:10 UTCJul 6, 12:50 UTC2h 40m
2026-07-06 TOM2VK - Jul 6, 05:30 UTCJul 6, 07:50 UTC2h 20m
2026-07-05 TOM10Y IBZ → MAN Jul 5, 18:50 UTCJul 5, 21:10 UTC2h 20m
2026-07-05 TOM3BV MAN → IBZ Jul 5, 15:20 UTCJul 5, 17:30 UTC2h 10m
2026-07-05 TOM6NK - Jul 5, 10:35 UTCJul 5, 13:50 UTC3h 15m
2026-07-05 TOM1WK - Jul 5, 06:10 UTCJul 5, 08:40 UTC2h 30m
2026-07-04 TOM23G - Jul 4, 18:20 UTCJul 4, 22:25 UTC4h 5m
2026-07-04 TOM8KE PFO → PFO Jul 4, 13:20 UTCJul 4, 16:40 UTC3h 20m
2026-07-04 TOM2BA CWL → TFS Jul 4, 09:10 UTCJul 4, 11:15 UTC2h 5m
2026-07-04 TOM7WJ AGP → CWL Jul 4, 06:05 UTCJul 4, 07:45 UTC1h 40m
2026-07-03 TOM21T - Jul 3, 22:00 UTCJul 4, 01:00 UTC3h 0m
2026-07-03 TOM668 - Jul 3, 17:20 UTCJul 3, 20:10 UTC2h 50m
2026-07-03 TOM11D - Jul 3, 11:25 UTCJul 3, 15:40 UTC4h 15m
2026-07-03 TOM8LW REU → MAN Jul 3, 05:55 UTCJul 3, 09:30 UTC3h 35m
2026-07-02 TOM7AJ KGS → MAN Jul 2, 21:30 UTCJul 3, 01:40 UTC4h 10m
2026-07-02 TOM3PE MAN → KGS Jul 2, 16:30 UTCJul 2, 20:05 UTC3h 35m
2026-07-02 TOM8NH - Jul 2, 12:10 UTCJul 2, 14:30 UTC2h 20m
2026-07-02 TOM1TD - Jul 2, 08:25 UTCJul 2, 10:25 UTC2h 0m
2026-07-01 TOM7BM - Jul 1, 18:35 UTCJul 1, 22:35 UTC4h 0m
2026-07-01 TOM8GC - Jul 1, 13:05 UTCJul 1, 16:50 UTC3h 45m
2026-07-01 TOM7TL - Jul 1, 09:20 UTCJul 1, 11:30 UTC2h 10m

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

Mode-S 400FF4 frequently asked

What is Mode-S code 400FF4?
400FF4 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-FDZD.
Where is Mode-S 400FF4 registered?
Mode-S code 400FF4 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 400FF4 broadcasting right now?
Yes. Mode-S 400FF4 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 400FF4, octal 20007764, decimal 4,198,388.
What flights does 400FF4 operate?
Mode-S 400FF4 has broadcast 20 distinct callsigns, including TOM8KE, TOM23G, TOM213, TOM9TM, TOM86L.