sensors Mode-S transponder

424C4A

ICAO 24-bit transponder address · allocated to United Kingdom

Currently assigned to M-IIII · GULFSTREAM G650

Hex
424C4A
Octal
20446112
Decimal
4,344,906
Country
GB
Tail
M-IIII
Type
GLF6
No current signal · last broadcast 6d ago
Flights observed
16
Distinct callsigns
1
Country
GB
Last broadcast
6d ago

Last known position

Most recent position reported by Mode-S 424C4A.

Country allocation

The ICAO 24-bit address 424C4A 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
MIIII - 16 2026-07-20

Recent flights last 16

DateFlightRouteTakeoffLandingDuration
2026-07-20 MIIII - Jul 20, 01:55 UTCJul 20, 11:35 UTC9h 40m
2026-07-19 MIIII - Jul 19, 00:10 UTCJul 19, 11:00 UTC10h 50m
2026-07-04 MIIII - Jul 4, 23:40 UTCJul 5, 02:35 UTC2h 55m
2026-07-03 MIIII - Jul 3, 12:25 UTCJul 3, 15:55 UTC3h 30m
2026-06-26 MIIII - Jun 26, 14:15 UTCJun 26, 18:24 UTC4h 10m
2026-06-24 MIIII LAS → LTN Jun 24, 00:09 UTCJun 24, 09:00 UTC8h 50m
2026-06-22 MIIII ATL → LAS Jun 22, 16:45 UTCJun 22, 20:19 UTC3h 35m
2026-06-21 MIIII - Jun 21, 04:54 UTCJun 21, 14:15 UTC9h 20m
2026-06-16 MIIII FLL → CIA Jun 16, 03:30 UTCJun 16, 12:20 UTC8h 50m
2026-06-15 MIIII IAD → FLL Jun 15, 13:10 UTCJun 15, 15:04 UTC1h 55m
2026-06-13 MIIII - Jun 13, 23:50 UTCJun 14, 11:05 UTC11h 15m
2026-06-11 MIIII - Jun 11, 15:50 UTCJun 11, 19:45 UTC3h 55m
2026-06-04 MIIII - Jun 4, 01:40 UTCJun 4, 06:30 UTC4h 50m
2026-06-02 MIIII - Jun 2, 18:25 UTCJun 2, 22:00 UTC3h 35m
2026-05-31 MIIII - May 31, 23:30 UTCJun 1, 03:45 UTC4h 15m
2026-05-05 MIIII - May 5, 14:50 UTCMay 5, 15:30 UTC40m

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 M-IIII page for operator, model, and routing details .

Mode-S 424C4A frequently asked

What is Mode-S code 424C4A?
424C4A is an ICAO 24-bit transponder address. Allocated to United Kingdom. Assigned to M-IIII.
Where is Mode-S 424C4A registered?
Mode-S code 424C4A 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 424C4A broadcasting right now?
No active broadcast right now. Last signal was 6d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 424C4A, octal 20446112, decimal 4,344,906.
What flights does 424C4A operate?
Mode-S 424C4A has broadcast 1 distinct callsign, including MIIII.