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
No current signal · last broadcast 3h ago
Flights observed
132
Distinct callsigns
20
Country
GB
Last broadcast
3h ago

Last known position

Most recent position reported by Mode-S 400FF4.

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
TOM9BJ - 3 2026-04-13
TOM5TN TUI Airways 3 2026-04-15
TOM3WN TUI Airways 3 2026-05-22
TOM3LY - 3 2026-04-13
TOM32K TUI Airways 3 2026-04-14
TOM9TM TUI Airways 2 2026-05-23
TOM9KN TUI Airways 2 2026-05-22
TOM8VA TUI Airways 2 2026-05-26
TOM88D - 2 2026-04-17
TOM80L TUI Airways 2 2026-04-16
TOM7LN TUI Airways 2 2026-05-23
TOM5XY TUI Airways 2 2026-05-23
TOM536 TUI Airways 2 2026-05-26
TOM4DY TUI Airways 2 2026-04-16
TOM41H - 2 2026-04-17
TOM3XE TUI Airways 2 2026-04-25
TOM3AG TUI Airways 2 2026-04-15
TOM30J - 2 2026-04-18
TOM213 TUI Airways 2 2026-05-23
TOM1EV TUI Airways 2 2026-04-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 TOM1XC BJV → BRS May 29, 20:50 UTCMay 30, 01:30 UTC4h 40m
2026-05-29 TOM7MV - May 29, 15:25 UTCMay 29, 19:40 UTC4h 15m
2026-05-29 TOM4HA ALC → MAN May 29, 11:10 UTCMay 29, 13:50 UTC2h 40m
2026-05-29 TOM2BV MAN → ALC May 29, 07:25 UTCMay 29, 09:35 UTC2h 10m
2026-05-28 TOM7AJ KGS → MAN May 28, 21:45 UTCMay 29, 01:40 UTC3h 55m
2026-05-28 TOM3PE MAN → KGS May 28, 16:25 UTCMay 28, 20:15 UTC3h 50m
2026-05-28 TOM8NH - May 28, 12:15 UTCMay 28, 14:35 UTC2h 20m
2026-05-28 TOM1TD HRG → HRG May 28, 08:45 UTCMay 28, 10:55 UTC2h 10m
2026-05-26 TOM8VA EFL → MAN May 26, 22:20 UTCMay 27, 01:24 UTC3h 5m
2026-05-26 TOM536 MAN → RAK May 26, 17:25 UTCMay 26, 20:24 UTC3h 0m
2026-05-26 TOM86L BVC → BHX May 26, 11:24 UTCMay 26, 14:40 UTC3h 15m
2026-05-26 TOM9KY INN → BHX May 26, 06:49 UTCMay 26, 10:10 UTC3h 20m
2026-05-25 TOM1AB ZTH → BHX May 25, 22:15 UTCMay 26, 02:19 UTC4h 5m
2026-05-25 TOM7XY PMI → CWL May 25, 16:10 UTCMay 25, 20:30 UTC4h 20m
2026-05-25 TOM7AN BRS → NAP May 25, 10:55 UTCMay 25, 13:20 UTC2h 25m
2026-05-25 TOM3FL MAN → SPU May 25, 07:10 UTCMay 25, 09:25 UTC2h 15m
2026-05-24 TOM4YB BRS → BOJ May 24, 18:10 UTCMay 24, 20:25 UTC2h 15m
2026-05-24 TOM5GL EMA → IBZ May 24, 14:15 UTCMay 24, 16:35 UTC2h 20m
2026-05-24 TOM67C - May 24, 08:55 UTCMay 24, 11:10 UTC2h 15m
2026-05-24 TOM6KX FUE → BRS May 24, 05:30 UTCMay 24, 07:45 UTC2h 15m
2026-05-23 TOM213 DLM → MAN May 23, 22:20 UTCMay 24, 02:20 UTC4h 0m
2026-05-23 TOM5XY BRS → ZTH May 23, 16:15 UTCMay 23, 20:05 UTC3h 50m
2026-05-23 TOM7LN RHO → LTN May 23, 11:55 UTCMay 23, 14:15 UTC2h 20m
2026-05-23 TOM9TM LGW → HER May 23, 07:25 UTCMay 23, 09:50 UTC2h 25m
2026-05-22 TOM27A CFU → MAN May 22, 17:35 UTCMay 22, 20:35 UTC3h 0m
2026-05-22 TOM7YW BHX → TFS May 22, 12:55 UTCMay 22, 15:45 UTC2h 50m
2026-05-22 TOM9KN GLA → TFS May 22, 08:45 UTCMay 22, 10:45 UTC2h 0m
2026-05-22 TOM3WN MAN → REU May 22, 05:20 UTCMay 22, 07:10 UTC1h 50m
2026-05-21 TOM14N LGW → PUY May 21, 17:50 UTCMay 21, 21:20 UTC3h 30m
2026-05-21 TOM30E MAN → ALC May 21, 13:30 UTCMay 21, 16:35 UTC3h 5m
2026-05-21 TOM40A STN → TFS May 21, 09:35 UTCMay 21, 12:05 UTC2h 30m
2026-05-21 TOM3DX EMA → TFS May 21, 06:10 UTCMay 21, 08:25 UTC2h 15m
2026-05-20 TOM603 AYT → MAN May 20, 11:00 UTCMay 20, 15:25 UTC4h 25m
2026-05-20 TOM51C MAN → AYT May 20, 05:45 UTCMay 20, 09:30 UTC3h 45m
2026-05-19 TOM8VA EFL → MAN May 19, 21:55 UTCMay 20, 01:05 UTC3h 10m
2026-05-19 TOM536 MAN → RAK May 19, 16:50 UTCMay 19, 20:10 UTC3h 20m
2026-05-19 TOM4HK KGS → EMA May 19, 11:10 UTCMay 19, 15:00 UTC3h 50m
2026-05-19 TOM77G BHX → RAK May 19, 06:05 UTCMay 19, 09:50 UTC3h 45m
2026-05-18 TOM27G IBZ → EMA May 18, 20:15 UTCMay 18, 22:35 UTC2h 20m
2026-05-18 TOM1FX LGW → FAO May 18, 16:35 UTCMay 18, 18:35 UTC1h 59m
2026-05-18 TOM7VG LGW → INN May 18, 10:30 UTCMay 18, 13:50 UTC3h 20m
2026-05-18 TOM4DB LGW → RHO May 18, 06:05 UTCMay 18, 09:10 UTC3h 5m
2026-05-16 TOM213 DLM → MAN May 16, 20:50 UTCMay 17, 01:05 UTC4h 15m
2026-05-16 TOM5XY BRS → ZTH May 16, 15:45 UTCMay 16, 19:20 UTC3h 35m
2026-05-16 TOM7LN RHO → LTN May 16, 11:41 UTCMay 16, 14:05 UTC2h 25m
2026-05-16 TOM9TM LGW → HER May 16, 07:25 UTCMay 16, 09:56 UTC2h 30m
2026-05-15 TOM9KN GLA → TFS May 15, 13:00 UTCMay 15, 15:10 UTC2h 9m
2026-05-15 TOM3WN MAN → REU May 15, 11:30 UTCMay 15, 11:40 UTC10m
2026-05-15 TOM3WN MAN → REU May 15, 06:10 UTCMay 15, 08:40 UTC2h 30m
2026-05-14 TOM32V LGW → FUE May 14, 22:25 UTCMay 15, 02:25 UTC4h 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 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?
No active broadcast right now. Last signal was 3h ago.
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 TOM9BJ, TOM5TN, TOM3WN, TOM3LY, TOM32K.