sensors Mode-S transponder

4D21DC

ICAO 24-bit transponder address · allocated to Malta

Currently assigned to 9H-NEC · AIRBUS A-320neo

Hex
4D21DC
Octal
23220734
Decimal
5,054,940
Country
MT
Tail
9H-NEC
Type
A20N
No current signal · last broadcast 4h ago
Flights observed
227
Distinct callsigns
20
Country
MT
Last broadcast
4h ago

Last known position

Most recent position reported by Mode-S 4D21DC.

Country allocation

The ICAO 24-bit address 4D21DC 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 20 distinct

Callsign Airline Flights Last seen
KMM394 - 15 2026-05-28
KMM395 - 14 2026-05-28
KMM103 - 11 2026-05-27
KMM102 - 11 2026-05-27
KMM420 - 10 2026-05-28
KMM421 - 9 2026-05-28
KMM615 - 8 2026-05-19
KMM614 - 8 2026-05-19
KMM467 - 8 2026-05-29
KMM466 - 8 2026-05-29
KMM625 - 7 2026-05-19
KMM624 - 7 2026-05-19
KMM613 - 7 2026-05-19
KMM612 - 7 2026-05-19
KMM101 - 7 2026-05-27
KMM100A - 7 2026-05-27
KMM514 - 6 2026-05-25
KMM515 - 5 2026-05-25
KMM309 - 5 2026-05-23
KMM117 - 5 2026-05-29

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 KMM467 ORY → MLA May 29, 19:10 UTCMay 29, 21:25 UTC2h 15m
2026-05-29 KMM466 MLA → ORY May 29, 15:20 UTCMay 29, 17:45 UTC2h 25m
2026-05-29 KMM117 LGW → MLA May 29, 11:00 UTCMay 29, 13:45 UTC2h 45m
2026-05-29 KMM116 MLA → LGW May 29, 06:30 UTCMay 29, 09:35 UTC3h 5m
2026-05-28 KMM421 BRU → MLA May 28, 18:20 UTCMay 28, 20:55 UTC2h 35m
2026-05-28 KMM420 MLA → BRU May 28, 14:20 UTCMay 28, 17:05 UTC2h 45m
2026-05-28 KMM395 AMS → MLA May 28, 10:30 UTCMay 28, 13:10 UTC2h 40m
2026-05-28 KMM394 MLA → AMS May 28, 05:50 UTCMay 28, 08:45 UTC2h 55m
2026-05-27 KMM103 LHR → MLA May 27, 19:50 UTCMay 27, 22:35 UTC2h 45m
2026-05-27 KMM102 MLA → LHR May 27, 15:10 UTCMay 27, 18:15 UTC3h 5m
2026-05-27 KMM101 LHR → MLA May 27, 10:15 UTCMay 27, 12:55 UTC2h 40m
2026-05-27 KMM100A MLA → LHR May 27, 05:04 UTCMay 27, 08:05 UTC3h 1m
2026-05-26 KMM539 PRG → MLA May 26, 19:34 UTCMay 26, 21:44 UTC2h 10m
2026-05-26 KMM538 MLA → PRG May 26, 16:10 UTCMay 26, 18:30 UTC2h 20m
2026-05-26 KMM101 - May 26, 10:20 UTCMay 26, 13:10 UTC2h 50m
2026-05-26 KMM100A MLA → LHR May 26, 05:25 UTCMay 26, 08:30 UTC3h 5m
2026-05-25 KMM421 BRU → MLA May 25, 18:35 UTCMay 25, 21:04 UTC2h 29m
2026-05-25 KMM420 MLA → BRU May 25, 14:55 UTCMay 25, 17:25 UTC2h 30m
2026-05-25 KMM515 VIE → MLA May 25, 10:35 UTCMay 25, 12:20 UTC1h 45m
2026-05-25 KMM514 MLA → VIE May 25, 07:10 UTCMay 25, 09:10 UTC2h 0m
2026-05-25 KMM641 - May 25, 05:40 UTCMay 25, 06:00 UTC20m
2026-05-25 KMM640 - May 25, 04:05 UTCMay 25, 04:35 UTC30m
2026-05-24 KMM377 - May 24, 19:20 UTCMay 24, 21:35 UTC2h 15m
2026-05-24 KMM376 MLA → BER May 24, 15:35 UTCMay 24, 18:20 UTC2h 45m
2026-05-24 KMM117 LGW → MLA May 24, 11:20 UTCMay 24, 14:15 UTC2h 55m
2026-05-24 KMM116 MLA → LGW May 24, 06:40 UTCMay 24, 09:30 UTC2h 50m
2026-05-23 KMM643 - May 23, 20:05 UTCMay 23, 20:30 UTC25m
2026-05-23 KMM642 - May 23, 18:45 UTCMay 23, 19:05 UTC20m
2026-05-23 KMM309 MUC → MLA May 23, 16:05 UTCMay 23, 17:55 UTC1h 50m
2026-05-23 KMM308 MLA → MUC May 23, 12:15 UTCMay 23, 14:25 UTC2h 10m
2026-05-23 KMM587 MAD → MLA May 23, 08:25 UTCMay 23, 10:40 UTC2h 15m
2026-05-23 KMM586 MLA → MAD May 23, 04:15 UTCMay 23, 06:30 UTC2h 15m
2026-05-22 KMM467 ORY → MLA May 22, 19:15 UTCMay 22, 21:30 UTC2h 15m
2026-05-22 KMM466 MLA → ORY May 22, 15:25 UTCMay 22, 17:55 UTC2h 30m
2026-05-22 KMM117 - May 22, 11:35 UTCMay 22, 14:05 UTC2h 30m
2026-05-22 KMM116 MLA → LGW May 22, 06:40 UTCMay 22, 09:45 UTC3h 5m
2026-05-21 KMM3119 LGW → MLA May 21, 16:50 UTCMay 21, 19:25 UTC2h 35m
2026-05-21 KMM9118 MLA → LGW May 21, 12:05 UTCMay 21, 15:15 UTC3h 10m
2026-05-21 KMM785 - May 21, 08:00 UTCMay 21, 10:00 UTC2h 0m
2026-05-21 KMM784 - May 21, 04:25 UTCMay 21, 06:15 UTC1h 50m
2026-05-20 KMM421 - May 20, 18:20 UTCMay 20, 20:35 UTC2h 15m
2026-05-20 KMM420 MLA → BRU May 20, 14:25 UTCMay 20, 17:10 UTC2h 45m
2026-05-20 KMM395 AMS → MLA May 20, 10:25 UTCMay 20, 13:00 UTC2h 35m
2026-05-20 KMM394 - May 20, 05:45 UTCMay 20, 08:40 UTC2h 55m
2026-05-19 KMM615 - May 19, 19:15 UTCMay 19, 20:15 UTC1h 0m
2026-05-19 KMM614 - May 19, 16:30 UTCMay 19, 17:45 UTC1h 15m
2026-05-19 KMM625 LIN → MLA May 19, 13:40 UTCMay 19, 15:15 UTC1h 35m
2026-05-19 KMM624 MLA → LIN May 19, 10:50 UTCMay 19, 12:35 UTC1h 45m
2026-05-19 KMM613 - May 19, 08:25 UTCMay 19, 09:25 UTC1h 0m
2026-05-19 KMM612 - May 19, 05:00 UTCMay 19, 06:15 UTC1h 15m

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

Mode-S 4D21DC frequently asked

What is Mode-S code 4D21DC?
4D21DC is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-NEC.
Where is Mode-S 4D21DC registered?
Mode-S code 4D21DC is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D21DC broadcasting right now?
No active broadcast right now. Last signal was 4h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D21DC, octal 23220734, decimal 5,054,940.
What flights does 4D21DC operate?
Mode-S 4D21DC has broadcast 20 distinct callsigns, including KMM394, KMM395, KMM103, KMM102, KMM420.