sensors Mode-S transponder

4D21DE

ICAO 24-bit transponder address · allocated to Malta

Currently assigned to 9H-CBH · DASSAULT Falcon 7X

Hex
4D21DE
Octal
23220736
Decimal
5,054,942
Country
MT
Tail
9H-CBH
Type
FA7X
No current signal · last broadcast 16h ago
Flights observed
1
Distinct callsigns
1
Country
MT
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S 4D21DE.

Country allocation

The ICAO 24-bit address 4D21DE falls within the block assigned to Malta (MT) by ICAO Annex 10, Volume III. Every aircraft registered in Malta 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
AJD22BH - 1 2026-04-14

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-04-14 AJD22BH - Apr 14, 10:00 UTCApr 14, 19:30 UTC9h 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 9H-CBH page for operator, model, and routing details .

Mode-S 4D21DE frequently asked

What is Mode-S code 4D21DE?
4D21DE is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-CBH.
Where is Mode-S 4D21DE registered?
Mode-S code 4D21DE is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D21DE broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D21DE, octal 23220736, decimal 5,054,942.
What flights does 4D21DE operate?
Mode-S 4D21DE has broadcast 1 distinct callsign, including AJD22BH.