sensors Mode-S transponder

4D239D

ICAO 24-bit transponder address · allocated to Malta

Currently assigned to 9H-ZTC · AIRBUS A-321

Hex
4D239D
Octal
23221635
Decimal
5,055,389
Country
MT
Tail
9H-ZTC
Type
A321
No current signal · last broadcast 1d ago
Flights observed
3
Distinct callsigns
2
Country
MT
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 4D239D.

Country allocation

The ICAO 24-bit address 4D239D 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 2 distinct

Callsign Airline Flights Last seen
BCS7DP - 2 2026-04-13
BCS43A European Air Transport 1 2026-04-13

Recent flights last 3

DateFlightRouteTakeoffLandingDuration
2026-04-13 BCS43A NTE → LEJ Apr 13, 20:20 UTCApr 13, 21:55 UTC1h 35m
2026-04-13 BCS7DP - Apr 13, 03:55 UTCApr 13, 04:15 UTC20m
2026-04-13 BCS7DP - Apr 13, 02:25 UTCApr 13, 04:15 UTC1h 50m

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-ZTC page for operator, model, and routing details .

Mode-S 4D239D frequently asked

What is Mode-S code 4D239D?
4D239D is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-ZTC.
Where is Mode-S 4D239D registered?
Mode-S code 4D239D is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D239D broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D239D, octal 23221635, decimal 5,055,389.
What flights does 4D239D operate?
Mode-S 4D239D has broadcast 2 distinct callsigns, including BCS7DP, BCS43A.