Apparatus

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sensors Mode-S transponder

4D012B

ICAO 24-bit transponder address · allocated to Luxembourg

Currently assigned to LX-GCL · BOEING 747-400

Hex
4D012B
Octal
23200453
Decimal
5,046,571
Country
LU
Tail
LX-GCL
Type
B744
No current signal · last broadcast 4h ago
Flights observed
170
Distinct callsigns
20
Country
LU
Last broadcast
4h ago

Last known position

Most recent position reported by Mode-S 4D012B.

Country allocation

The ICAO 24-bit address 4D012B falls within the block assigned to Luxembourg (LU) by ICAO Annex 10, Volume III. Every aircraft registered in Luxembourg 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
CLX58 - 10 2026-07-03
CLX49 - 8 2026-06-10
CLX9872 - 7 2026-06-24
CLX7602 Cargolux 7 2026-06-09
CLX708 - 7 2026-06-29
CLX2 - 7 2026-06-20
CLX6 - 6 2026-05-24
CLX57 - 6 2026-07-05
CLX57R Cargolux 5 2026-04-13
CLX7855 - 4 2026-06-27
CLX6697 Cargolux 4 2026-05-31
CLX65 - 4 2026-07-12
CLX34E Cargolux 4 2026-04-16
CLX32 - 4 2026-06-24
CLX18W Cargolux 4 2026-04-17
CLX79 - 3 2026-07-13
CLX74A Cargolux 3 2026-06-21
CLX7332 Cargolux 3 2026-06-17
CLX72W Cargolux 3 2026-05-25
CLX492 - 3 2026-06-04

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 CLX79 - Jul 13, 11:15 UTCJul 14, 07:30 UTC20h 15m
2026-07-12 CLX65 - Jul 12, 22:50 UTCJul 13, 18:35 UTC19h 45m
2026-07-12 CLX65 - Jul 12, 21:15 UTCJul 13, 18:35 UTC21h 20m
2026-07-12 CLX56 - Jul 12, 08:55 UTCJul 12, 13:25 UTC4h 30m
2026-07-11 CLX56 - Jul 11, 12:50 UTCJul 12, 12:45 UTC23h 55m
2026-07-11 CLX9726 - Jul 11, 10:55 UTCJul 12, 10:15 UTC23h 20m
2026-07-10 CLX17 - Jul 10, 10:15 UTCJul 11, 04:30 UTC18h 16m
2026-07-09 CLX43 - Jul 9, 22:50 UTCJul 10, 18:25 UTC19h 35m
2026-07-09 CLX43 - Jul 9, 20:55 UTCJul 10, 18:25 UTC21h 30m
2026-07-09 CLX42 - Jul 9, 11:45 UTCJul 9, 16:10 UTC4h 25m
2026-07-08 CLX42 - Jul 8, 17:10 UTCJul 9, 16:10 UTC23h 0m
2026-07-08 CLX9723 - Jul 8, 14:50 UTCJul 9, 14:45 UTC23h 55m
2026-07-08 CLX9723 - Jul 8, 13:45 UTCJul 9, 12:45 UTC23h 0m
2026-07-06 CLX7957 HKG → GYD Jul 6, 15:35 UTCJul 7, 04:05 UTC12h 30m
2026-07-06 CLX7957 HKG → GYD Jul 6, 10:25 UTCJul 6, 10:40 UTC15m
2026-07-06 CLX7956 - Jul 6, 06:00 UTCJul 6, 06:30 UTC30m
2026-07-06 CLX7956 - Jul 6, 05:00 UTCJul 6, 05:15 UTC15m
2026-07-05 CLX8S - Jul 5, 11:10 UTCJul 5, 23:25 UTC12h 15m
2026-07-05 CLX57 - Jul 5, 03:35 UTCJul 5, 08:05 UTC4h 30m
2026-07-04 CLX57 - Jul 4, 11:00 UTCJul 5, 08:05 UTC21h 5m
2026-07-03 CLX58 - Jul 3, 21:35 UTCJul 4, 11:20 UTC13h 45m
2026-07-02 CLX65 - Jul 2, 07:55 UTCJul 2, 12:15 UTC4h 20m
2026-07-01 CLX65 - Jul 1, 10:50 UTCJul 2, 10:45 UTC23h 55m
2026-07-01 CLX7603 - Jul 1, 08:50 UTCJul 2, 08:45 UTC23h 55m
2026-07-01 CLX7603 - Jul 1, 06:55 UTCJul 1, 11:00 UTC4h 5m
2026-06-29 CLX708 BUD → LUX Jun 29, 18:25 UTCJun 29, 19:49 UTC1h 25m
2026-06-29 CLX708 - Jun 29, 11:45 UTCJun 29, 14:50 UTC3h 5m
2026-06-29 CLX708 - Jun 29, 01:39 UTCJun 29, 02:00 UTC20m
2026-06-27 CLX7855 - Jun 27, 20:39 UTCJun 27, 20:59 UTC20m
2026-06-27 CLX7855 - Jun 27, 05:04 UTCJun 27, 16:04 UTC11h 0m
2026-06-26 CLX7955 HKG → HKG Jun 26, 09:50 UTCJun 26, 21:55 UTC12h 5m
2026-06-26 CLX7955 HKG → HKG Jun 26, 04:39 UTCJun 26, 04:50 UTC10m
2026-06-25 CLX7954 LUX → BAH Jun 25, 10:15 UTCJun 25, 21:25 UTC11h 10m
2026-06-24 CLX32 - Jun 24, 18:34 UTCJun 25, 07:30 UTC12h 55m
2026-06-24 CLX32 - Jun 24, 11:05 UTCJun 25, 07:30 UTC20h 25m
2026-06-24 CLX9872 - Jun 24, 03:04 UTCJun 24, 18:55 UTC15h 50m
2026-06-24 CLX9872 - Jun 24, 01:30 UTCJun 24, 01:34 UTC5m
2026-06-23 CLX9872 - Jun 23, 21:45 UTCJun 24, 00:20 UTC2h 35m
2026-06-22 CLX67 MXP → LUX Jun 22, 21:19 UTCJun 22, 22:15 UTC55m
2026-06-22 CLX67 - Jun 22, 08:00 UTCJun 22, 18:49 UTC10h 50m
2026-06-21 CLX5 - Jun 21, 17:50 UTCJun 22, 04:54 UTC11h 5m
2026-06-21 CLX74A JFK → LUX Jun 21, 05:35 UTCJun 21, 11:59 UTC6h 25m
2026-06-20 CLX2 - Jun 20, 18:29 UTCJun 21, 02:20 UTC7h 50m
2026-06-20 CLX597 - Jun 20, 10:39 UTCJun 20, 14:59 UTC4h 20m
2026-06-20 CLX3739 - Jun 20, 01:24 UTCJun 20, 01:39 UTC15m
2026-06-19 CLX7366 - Jun 19, 21:30 UTCJun 19, 23:09 UTC1h 40m
2026-06-19 CLX7355 NRT → HKG Jun 19, 15:34 UTCJun 19, 18:30 UTC2h 55m
2026-06-18 CLX7355 NRT → HKG Jun 18, 21:50 UTCJun 19, 08:24 UTC10h 34m
2026-06-18 CLX531 - Jun 18, 09:15 UTCJun 18, 13:35 UTC4h 20m
2026-06-17 CLX531 - Jun 17, 23:20 UTCJun 17, 23:40 UTC20m

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 LX-GCL page for operator, model, and routing details .

Mode-S 4D012B frequently asked

What is Mode-S code 4D012B?
4D012B is an ICAO 24-bit transponder address. Allocated to Luxembourg. Assigned to LX-GCL.
Where is Mode-S 4D012B registered?
Mode-S code 4D012B is allocated to Luxembourg (LU). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D012B broadcasting right now?
No active broadcast right now. Last signal was 4h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D012B, octal 23200453, decimal 5,046,571.
What flights does 4D012B operate?
Mode-S 4D012B has broadcast 20 distinct callsigns, including CLX58, CLX49, CLX9872, CLX7602, CLX708.