sensors Mode-S transponder

4D23A1

ICAO 24-bit transponder address · allocated to Malta

Currently assigned to 9H-MLR · AIRBUS A-320

Hex
4D23A1
Octal
23221641
Decimal
5,055,393
Country
MT
Tail
9H-MLR
Type
A320
No current signal · last broadcast Apr 26, 15:40 UTC
Flights observed
29
Distinct callsigns
19
Country
MT
Last broadcast
Apr 26, 15:40 UTC

Last known position

Most recent position reported by Mode-S 4D23A1.

Country allocation

The ICAO 24-bit address 4D23A1 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 19 distinct

Callsign Airline Flights Last seen
MLH9938 - 2 2026-04-16
EWG9A Eurowings 2 2026-04-15
EWG89D - 2 2026-04-14
EWG5PC - 2 2026-04-15
EWG5B Eurowings 2 2026-04-15
EWG47B - 2 2026-04-13
EWG39J - 2 2026-04-15
EWG2YR - 2 2026-04-13
EWG1U - 2 2026-04-14
EWG17FR - 2 2026-04-13
MLH9965 - 1 2026-04-26
EWG8QZ - 1 2026-04-15
EWG7SU - 1 2026-04-13
EWG7F - 1 2026-04-14
EWG6PT Eurowings 1 2026-04-12
EWG4D Eurowings 1 2026-04-13
EWG3NP Eurowings 1 2026-04-15
EWG1WJ - 1 2026-04-13
EWG18C - 1 2026-04-14

Recent flights last 29

DateFlightRouteTakeoffLandingDuration
2026-04-26 MLH9965 - Apr 26, 13:25 UTCApr 26, 15:35 UTC2h 10m
2026-04-16 MLH9938 - Apr 16, 11:09 UTCApr 16, 11:35 UTC25m
2026-04-16 MLH9938 - Apr 16, 09:29 UTCApr 16, 11:04 UTC1h 35m
2026-04-15 EWG39J - Apr 15, 19:05 UTCApr 15, 19:25 UTC20m
2026-04-15 EWG39J - Apr 15, 18:10 UTCApr 15, 19:00 UTC50m
2026-04-15 EWG5PC - Apr 15, 17:05 UTCApr 15, 17:15 UTC10m
2026-04-15 EWG5PC - Apr 15, 16:05 UTCApr 15, 17:00 UTC55m
2026-04-15 EWG8QZ - Apr 15, 13:20 UTCApr 15, 14:55 UTC1h 34m
2026-04-15 EWG9A MXP → HAM Apr 15, 11:00 UTCApr 15, 11:55 UTC55m
2026-04-15 EWG9A MXP → HAM Apr 15, 10:10 UTCApr 15, 10:55 UTC45m
2026-04-15 EWG3NP LPA → DUS Apr 15, 07:01 UTCApr 15, 08:25 UTC1h 25m
2026-04-15 EWG5B HER → BER Apr 15, 05:00 UTCApr 15, 06:10 UTC1h 10m
2026-04-15 EWG5B HER → BER Apr 15, 04:40 UTCApr 15, 04:50 UTC10m
2026-04-14 EWG1U - Apr 14, 18:55 UTCApr 14, 20:25 UTC1h 30m
2026-04-14 EWG1U - Apr 14, 18:20 UTCApr 14, 18:45 UTC25m
2026-04-14 EWG18C - Apr 14, 15:05 UTCApr 14, 16:45 UTC1h 40m
2026-04-14 EWG89D - Apr 14, 09:10 UTCApr 14, 10:20 UTC1h 10m
2026-04-14 EWG89D - Apr 14, 08:05 UTCApr 14, 09:05 UTC1h 0m
2026-04-14 EWG7F - Apr 14, 05:15 UTCApr 14, 07:05 UTC1h 50m
2026-04-13 EWG17FR - Apr 13, 19:50 UTCApr 13, 20:05 UTC15m
2026-04-13 EWG17FR MUC → DUS Apr 13, 19:20 UTCApr 13, 20:05 UTC45m
2026-04-13 EWG1WJ DUS → MUC Apr 13, 17:05 UTCApr 13, 18:05 UTC1h 0m
2026-04-13 EWG2YR - Apr 13, 15:50 UTCApr 13, 16:00 UTC10m
2026-04-13 EWG2YR - Apr 13, 14:45 UTCApr 13, 16:00 UTC1h 15m
2026-04-13 EWG47B - Apr 13, 12:20 UTCApr 13, 13:30 UTC1h 10m
2026-04-13 EWG47B - Apr 13, 12:10 UTCApr 13, 13:30 UTC1h 20m
2026-04-13 EWG7SU - Apr 13, 08:35 UTCApr 13, 10:30 UTC1h 55m
2026-04-13 EWG4D DUS → BGO Apr 13, 05:10 UTCApr 13, 07:10 UTC2h 0m
2026-04-12 EWG6PT HER → DUS Apr 12, 17:15 UTCApr 12, 18:45 UTC1h 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-MLR page for operator, model, and routing details .

Mode-S 4D23A1 frequently asked

What is Mode-S code 4D23A1?
4D23A1 is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-MLR.
Where is Mode-S 4D23A1 registered?
Mode-S code 4D23A1 is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D23A1 broadcasting right now?
No active broadcast right now. Last signal was Apr 26, 15:40 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D23A1, octal 23221641, decimal 5,055,393.
What flights does 4D23A1 operate?
Mode-S 4D23A1 has broadcast 19 distinct callsigns, including MLH9938, EWG9A, EWG89D, EWG5PC, EWG5B.