Apparatus

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sensors Mode-S transponder

40773B

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to G-TUMK · BOEING 737 MAX 8

Hex
40773B
Octal
20073473
Decimal
4,224,827
Country
GB
Tail
G-TUMK
Type
B38M
No current signal · last broadcast Jul 26, 18:40 UTC
Flights observed
322
Distinct callsigns
20
Country
GB
Last broadcast
Jul 26, 18:40 UTC

Last known position

Most recent position reported by Mode-S 40773B.

Country allocation

The ICAO 24-bit address 40773B 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
TFL1579 - 7 2026-07-05
TOM55H TUI Airways 5 2026-05-25
TOM99C - 3 2026-06-30
TOM7DH - 3 2026-04-16
TOM788 - 3 2026-04-14
TOM610 TUI Airways 3 2026-07-25
TOM557 - 3 2026-04-15
TOM556 - 3 2026-04-15
TOM553 - 3 2026-06-25
TOM3EA TUI Airways 3 2026-06-30
TOM2XC TUI Airways 3 2026-04-17
TOM2VK TUI Airways 3 2026-05-25
TOM2PY TUI Airways 3 2026-04-21
TOM1EA - 3 2026-04-17
TOM863 - 2 2026-07-20
TOM84B TUI Airways 2 2026-06-20
TOM7PM - 2 2026-04-13
TOM7KJ TUI Airways 2 2026-06-09
TOM6PN TUI Airways 2 2026-05-10
TOM624 - 2 2026-07-10

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 TOM1FC TFS → LGW Jul 26, 14:45 UTCJul 26, 18:35 UTC3h 50m
2026-07-26 TOM3XT CWL → DBV Jul 26, 09:10 UTCJul 26, 12:35 UTC3h 25m
2026-07-26 TOM43V MAN → KEF Jul 26, 02:20 UTCJul 26, 04:20 UTC2h 0m
2026-07-25 TOM5LV CWL → TFS Jul 25, 22:30 UTCJul 26, 00:30 UTC2h 0m
2026-07-25 TOM610 LGW → BVC Jul 25, 08:40 UTCJul 25, 20:40 UTC12h 0m
2026-07-25 TOM999P - Jul 25, 06:50 UTCJul 25, 07:20 UTC30m
2026-07-24 TOM661 NBE → STN Jul 24, 20:20 UTCJul 24, 23:20 UTC3h 0m
2026-07-24 TOM660 STN → NBE Jul 24, 16:40 UTCJul 24, 19:15 UTC2h 35m
2026-07-24 TOM987P - Jul 24, 14:25 UTCJul 24, 14:45 UTC20m
2026-07-22 TOM989P LGW → LTN Jul 22, 12:40 UTCJul 22, 13:20 UTC40m
2026-07-22 TOM50E BHX → SID Jul 22, 05:20 UTCJul 22, 05:25 UTC5m
2026-07-21 TOM1GN AYT → LGW Jul 21, 21:45 UTCJul 22, 01:55 UTC4h 10m
2026-07-21 TOM506 LGW → AYT Jul 21, 16:35 UTCJul 21, 20:10 UTC3h 35m
2026-07-21 TOM2EV - Jul 21, 11:35 UTCJul 21, 14:50 UTC3h 15m
2026-07-21 TOM51D LGW → JSI Jul 21, 07:10 UTCJul 21, 09:55 UTC2h 45m
2026-07-20 TOM863 - Jul 20, 14:20 UTCJul 20, 18:10 UTC3h 50m
2026-07-20 TOM1XE - Jul 20, 09:20 UTCJul 20, 12:35 UTC3h 15m
2026-07-19 TOM6TL MAH → LGW Jul 19, 20:55 UTCJul 19, 22:45 UTC1h 50m
2026-07-19 TOM26A LGW → MAH Jul 19, 17:30 UTCJul 19, 19:10 UTC1h 40m
2026-07-19 TOM74T - Jul 19, 12:20 UTCJul 19, 15:40 UTC3h 20m
2026-07-19 TOM2BH FRA → FRA Jul 19, 07:55 UTCJul 19, 10:40 UTC2h 45m
2026-07-18 TOM349 CUN → GLA Jul 18, 19:25 UTCJul 18, 23:45 UTC4h 20m
2026-07-18 TOM348 LGW → AYT Jul 18, 14:25 UTCJul 18, 18:05 UTC3h 40m
2026-07-18 TOM17H - Jul 18, 10:30 UTCJul 18, 12:15 UTC1h 45m
2026-07-18 TOM34A MAN → HER Jul 18, 07:30 UTCJul 18, 09:00 UTC1h 30m
2026-07-17 TOM11J HER → STN Jul 17, 14:55 UTCJul 18, 02:05 UTC11h 10m
2026-07-17 TOM60M ZTH → MAN Jul 17, 10:30 UTCJul 17, 12:40 UTC2h 10m
2026-07-17 TOM9ML LGW → SPU Jul 17, 06:35 UTCJul 17, 08:25 UTC1h 50m
2026-07-16 TOM8EH LGW → HRG Jul 16, 21:45 UTCJul 17, 02:20 UTC4h 35m
2026-07-16 TOM93G LGW → PFO Jul 16, 16:44 UTCJul 16, 20:35 UTC3h 50m
2026-07-16 TOM50N - Jul 16, 12:00 UTCJul 16, 15:14 UTC3h 15m
2026-07-16 TOM6VG - Jul 16, 08:10 UTCJul 16, 10:55 UTC2h 45m
2026-07-15 TOM653 - Jul 15, 20:30 UTCJul 16, 01:25 UTC4h 55m
2026-07-15 TOM652 - Jul 15, 13:30 UTCJul 15, 17:50 UTC4h 20m
2026-07-15 TOM8AT IBZ → LGW Jul 15, 09:05 UTCJul 15, 11:00 UTC1h 55m
2026-07-15 TOM28Y LGW → IBZ Jul 15, 05:30 UTCJul 15, 07:30 UTC2h 0m
2026-07-14 TOM627 - Jul 14, 21:50 UTCJul 15, 01:40 UTC3h 49m
2026-07-14 TOM626 LGW → DLM Jul 14, 17:05 UTCJul 14, 20:20 UTC3h 15m
2026-07-14 TOM2EV - Jul 14, 11:15 UTCJul 14, 14:30 UTC3h 15m
2026-07-14 TOM51D - Jul 14, 07:05 UTCJul 14, 09:45 UTC2h 40m
2026-07-13 TOM771 - Jul 13, 19:10 UTCJul 14, 00:10 UTC5h 0m
2026-07-13 TOM770 LGW → HRG Jul 13, 12:35 UTCJul 13, 16:40 UTC4h 5m
2026-07-13 TOM43Y - Jul 13, 08:40 UTCJul 13, 10:50 UTC2h 10m
2026-07-13 TOM1LY LGW → MAH Jul 13, 05:25 UTCJul 13, 07:30 UTC2h 5m
2026-07-12 TOM1BY KGS → LGW Jul 12, 21:45 UTCJul 13, 01:25 UTC3h 40m
2026-07-12 TOM7BT BVC → BHX Jul 12, 16:50 UTCJul 12, 20:15 UTC3h 25m
2026-07-12 TOM47A MAN → SKG Jul 12, 11:30 UTCJul 12, 15:15 UTC3h 45m
2026-07-12 TOM81H - Jul 12, 06:15 UTCJul 12, 09:25 UTC3h 10m
2026-07-12 - - Jul 12, 05:20 UTCJul 12, 05:30 UTC10m
2026-07-11 TOM610 LGW → LGW Jul 11, 08:20 UTCJul 11, 20:20 UTC12h 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-TUMK page for operator, model, and routing details .

Mode-S 40773B frequently asked

What is Mode-S code 40773B?
40773B is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to G-TUMK.
Where is Mode-S 40773B registered?
Mode-S code 40773B 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 40773B broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 18:40 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 40773B, octal 20073473, decimal 4,224,827.
What flights does 40773B operate?
Mode-S 40773B has broadcast 20 distinct callsigns, including TFL1579, TOM55H, TOM99C, TOM7DH, TOM788.