sensors Mode-S transponder

4D23DA

ICAO 24-bit transponder address · allocated to Malta

Hex
4D23DA
Octal
23221732
Decimal
5,055,450
Country
MT
No current signal · last broadcast Jun 2, 15:55 UTC
Flights observed
1
Distinct callsigns
1
Country
MT
Last broadcast
Jun 2, 15:55 UTC

Last known position

Most recent position reported by Mode-S 4D23DA.

Country allocation

The ICAO 24-bit address 4D23DA 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
RYR1HP Ryanair 1 2026-06-02

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-06-02 RYR1HP FNI → OPO Jun 2, 15:20 UTCJun 2, 15:55 UTC35m

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 4D23DA frequently asked

What is Mode-S code 4D23DA?
4D23DA is an ICAO 24-bit transponder address. Allocated to Malta.
Where is Mode-S 4D23DA registered?
Mode-S code 4D23DA is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D23DA broadcasting right now?
No active broadcast right now. Last signal was Jun 2, 15:55 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D23DA, octal 23221732, decimal 5,055,450.
What flights does 4D23DA operate?
Mode-S 4D23DA has broadcast 1 distinct callsign, including RYR1HP.