sensors Mode-S transponder

451DBD

ICAO 24-bit transponder address · allocated to Bulgaria

Currently assigned to LZ-CGU · BOEING 737-400

Hex
451DBD
Octal
21216675
Decimal
4,529,597
Country
BG
Tail
LZ-CGU
Type
B734
No current signal · last broadcast 7h ago
Flights observed
133
Distinct callsigns
20
Country
BG
Last broadcast
7h ago

Last known position

Most recent position reported by Mode-S 451DBD.

Country allocation

The ICAO 24-bit address 451DBD falls within the block assigned to Bulgaria (BG) by ICAO Annex 10, Volume III. Every aircraft registered in Bulgaria 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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 BCS947 BEG → LEJ May 29, 21:15 UTCMay 29, 21:45 UTC30m
2026-05-29 BCS947 BEG → LEJ May 29, 18:05 UTCMay 29, 19:10 UTC1h 5m
2026-05-29 BCS942 EMA → MXP May 29, 06:25 UTCMay 29, 07:45 UTC1h 20m
2026-05-29 BCS942 EMA → MXP May 29, 03:10 UTCMay 29, 04:35 UTC1h 25m
2026-05-29 BCS2204 MXP → STN May 29, 00:50 UTCMay 29, 02:20 UTC1h 30m
2026-05-28 BCS943 BEG → BLQ May 28, 21:30 UTCMay 28, 22:05 UTC35m
2026-05-28 BCS943 BEG → BLQ May 28, 17:30 UTCMay 28, 18:30 UTC1h 0m
2026-05-28 BCS942 EMA → MXP May 28, 06:20 UTCMay 28, 07:45 UTC1h 25m
2026-05-28 BCS942 EMA → MXP May 28, 03:05 UTCMay 28, 04:25 UTC1h 20m
2026-05-28 BCS2204 MXP → STN May 28, 00:35 UTCMay 28, 02:05 UTC1h 30m
2026-05-27 BCS943 BEG → BLQ May 27, 21:25 UTCMay 27, 22:00 UTC35m
2026-05-27 BCS943 BEG → BLQ May 27, 17:45 UTCMay 27, 18:45 UTC1h 0m
2026-05-27 BCS942 EMA → MXP May 27, 06:29 UTCMay 27, 07:45 UTC1h 15m
2026-05-27 BCS942 EMA → MXP May 27, 03:04 UTCMay 27, 04:30 UTC1h 25m
2026-05-27 BCS2204 MXP → STN May 27, 00:34 UTCMay 27, 02:04 UTC1h 30m
2026-05-26 BCS943 BEG → BLQ May 26, 21:04 UTCMay 26, 21:40 UTC35m
2026-05-26 BCS943 BEG → BLQ May 26, 17:39 UTCMay 26, 18:40 UTC1h 0m
2026-05-26 BCS942 EMA → MXP May 26, 06:14 UTCMay 26, 07:40 UTC1h 25m
2026-05-26 BCS942 EMA → MXP May 26, 03:05 UTCMay 26, 04:35 UTC1h 30m
2026-05-26 BCS2204 MXP → STN May 26, 00:39 UTCMay 26, 02:10 UTC1h 30m
2026-05-25 BCS943 BEG → BLQ May 25, 21:15 UTCMay 25, 21:49 UTC35m
2026-05-25 BCS943 BEG → BLQ May 25, 17:30 UTCMay 25, 18:25 UTC55m
2026-05-25 BCS942 EMA → MXP May 25, 02:30 UTCMay 25, 03:55 UTC1h 25m
2026-05-22 BCS947 BEG → LEJ May 22, 21:25 UTCMay 22, 22:00 UTC35m
2026-05-22 BCS947 BEG → LEJ May 22, 18:00 UTCMay 22, 18:55 UTC55m
2026-05-22 BCS942 EMA → MXP May 22, 06:15 UTCMay 22, 07:40 UTC1h 25m
2026-05-22 BCS942 EMA → MXP May 22, 03:15 UTCMay 22, 04:40 UTC1h 25m
2026-05-22 BCS2204 MXP → STN May 22, 00:35 UTCMay 22, 02:05 UTC1h 30m
2026-05-21 BCS943 BEG → BLQ May 21, 21:00 UTCMay 21, 21:40 UTC40m
2026-05-21 BCS943 BEG → BLQ May 21, 17:25 UTCMay 21, 18:30 UTC1h 5m
2026-05-21 BCS942 EMA → MXP May 21, 06:20 UTCMay 21, 07:40 UTC1h 20m
2026-05-21 BCS942 EMA → MXP May 21, 03:10 UTCMay 21, 04:30 UTC1h 20m
2026-05-21 BCS2204 MXP → STN May 21, 00:35 UTCMay 21, 02:10 UTC1h 35m
2026-05-20 BCS943 BEG → BLQ May 20, 21:00 UTCMay 20, 21:40 UTC40m
2026-05-20 BCS943 BEG → BLQ May 20, 17:20 UTCMay 20, 18:25 UTC1h 5m
2026-05-20 BCS942 EMA → MXP May 20, 06:20 UTCMay 20, 07:35 UTC1h 15m
2026-05-20 BCS942 EMA → MXP May 20, 03:15 UTCMay 20, 04:40 UTC1h 26m
2026-05-20 BCS2204 MXP → STN May 20, 00:45 UTCMay 20, 02:20 UTC1h 35m
2026-05-19 BCS943 BEG → BLQ May 19, 21:10 UTCMay 19, 21:45 UTC35m
2026-05-19 BCS943 BEG → BLQ May 19, 17:15 UTCMay 19, 18:15 UTC1h 0m
2026-05-19 BCS942 EMA → MXP May 19, 06:15 UTCMay 19, 07:35 UTC1h 20m
2026-05-19 BCS942 EMA → MXP May 19, 03:05 UTCMay 19, 04:30 UTC1h 25m
2026-05-19 BCS2204 MXP → STN May 19, 00:30 UTCMay 19, 02:00 UTC1h 30m
2026-05-18 BCS943 BEG → BLQ May 18, 21:45 UTCMay 18, 22:35 UTC50m
2026-05-18 BCS943 BEG → BLQ May 18, 17:30 UTCMay 18, 18:35 UTC1h 4m
2026-05-18 BCS942 EMA → MXP May 18, 02:25 UTCMay 18, 03:50 UTC1h 25m
2026-05-15 BCS943 BEG → BLQ May 15, 18:10 UTCMay 15, 19:50 UTC1h 40m
2026-05-15 BCS942 EMA → MXP May 15, 06:15 UTCMay 15, 07:25 UTC1h 10m
2026-05-15 BCS942 EMA → MXP May 15, 03:05 UTCMay 15, 04:35 UTC1h 30m
2026-05-15 BCS2204 MXP → STN May 15, 00:40 UTCMay 15, 02:10 UTC1h 30m

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 LZ-CGU page for operator, model, and routing details .

Mode-S 451DBD frequently asked

What is Mode-S code 451DBD?
451DBD is an ICAO 24-bit transponder address. Allocated to Bulgaria. Assigned to LZ-CGU.
Where is Mode-S 451DBD registered?
Mode-S code 451DBD is allocated to Bulgaria (BG). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 451DBD broadcasting right now?
No active broadcast right now. Last signal was 7h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 451DBD, octal 21216675, decimal 4,529,597.
What flights does 451DBD operate?
Mode-S 451DBD has broadcast 20 distinct callsigns, including BCS942, BCS943, BCS2204, BCS8VJ, BCS12P.