sensors Mode-S transponder

424CA3

ICAO 24-bit transponder address · allocated to United Kingdom

Hex
424CA3
Octal
20446243
Decimal
4,344,995
Country
GB
No current signal · last broadcast 2h ago
Flights observed
5
Distinct callsigns
1
Country
GB
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S 424CA3.

Country allocation

The ICAO 24-bit address 424CA3 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 1 distinct

Callsign Airline Flights Last seen
MYTOY - 5 2026-05-07

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-05-07 MYTOY - May 7, 14:10 UTCMay 7, 14:25 UTC15m
2026-04-16 MYTOY - Apr 16, 13:30 UTCApr 16, 15:10 UTC1h 40m
2026-04-16 MYTOY - Apr 16, 11:09 UTCApr 16, 11:44 UTC35m
2026-04-16 MYTOY - Apr 16, 10:25 UTCApr 16, 11:04 UTC40m
2026-04-16 MYTOY - Apr 16, 07:09 UTCApr 16, 08:09 UTC1h 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.

Mode-S 424CA3 frequently asked

What is Mode-S code 424CA3?
424CA3 is an ICAO 24-bit transponder address. Allocated to United Kingdom.
Where is Mode-S 424CA3 registered?
Mode-S code 424CA3 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 424CA3 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 424CA3, octal 20446243, decimal 4,344,995.
What flights does 424CA3 operate?
Mode-S 424CA3 has broadcast 1 distinct callsign, including MYTOY.