sensors Mode-S transponder

4243C4

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to VQ-BVC · BOEING 747-8

Hex
4243C4
Octal
20441704
Decimal
4,342,724
Country
GB
Tail
VQ-BVC
Type
B748
No current signal · last broadcast 2h ago
Flights observed
5
Distinct callsigns
4
Country
GB
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S 4243C4.

Country allocation

The ICAO 24-bit address 4243C4 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 4 distinct

Callsign Airline Flights Last seen
AZG124 Sakaviaservice 2 2026-05-31
AZG904 Sakaviaservice 1 2026-05-31
AZG648 Sakaviaservice 1 2026-06-01
AZG647 Sakaviaservice 1 2026-06-01

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-06-01 AZG648 HKG → HKG Jun 1, 14:00 UTCJun 1, 14:15 UTC15m
2026-06-01 AZG647 DMM → HKG Jun 1, 10:50 UTCJun 1, 11:20 UTC30m
2026-05-31 AZG124 ICN → GYD May 31, 15:50 UTCMay 31, 21:00 UTC5h 10m
2026-05-31 AZG124 ICN → GYD May 31, 15:35 UTCMay 31, 15:40 UTC5m
2026-05-31 AZG904 NRT → GYD May 31, 08:25 UTCMay 31, 10:10 UTC1h 45m

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 VQ-BVC page for operator, model, and routing details .

Mode-S 4243C4 frequently asked

What is Mode-S code 4243C4?
4243C4 is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to VQ-BVC.
Where is Mode-S 4243C4 registered?
Mode-S code 4243C4 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 4243C4 broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4243C4, octal 20441704, decimal 4,342,724.
What flights does 4243C4 operate?
Mode-S 4243C4 has broadcast 4 distinct callsigns, including AZG124, AZG904, AZG648, AZG647.