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sensors Mode-S transponder

4D21CD

ICAO 24-bit transponder address · allocated to Malta

Hex
4D21CD
Octal
23220715
Decimal
5,054,925
Country
MT
No current signal · last broadcast 26d ago
Flights observed
137
Distinct callsigns
5
Country
MT
Last broadcast
26d ago

Last known position

Most recent position reported by Mode-S 4D21CD.

Country allocation

The ICAO 24-bit address 4D21CD 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 5 distinct

Callsign Airline Flights Last seen
VJT643 - 130 2026-07-26
VJT900W - 3 2026-06-26
VJT942W - 2 2026-05-30
VJT997W - 1 2026-06-21
VJT978W - 1 2026-07-09

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 VJT643 CFR → RKV Jul 26, 14:40 UTCJul 26, 17:50 UTC3h 10m
2026-07-26 VJT643 - Jul 26, 09:55 UTCJul 26, 11:20 UTC1h 25m
2026-07-26 VJT643 - Jul 26, 07:50 UTCJul 26, 08:25 UTC35m
2026-07-25 VJT643 - Jul 25, 15:00 UTCJul 25, 15:35 UTC35m
2026-07-25 VJT643 - Jul 25, 12:30 UTCJul 25, 13:25 UTC55m
2026-07-25 VJT643 - Jul 25, 10:15 UTCJul 25, 11:20 UTC1h 5m
2026-07-21 VJT643 - Jul 21, 10:30 UTCJul 21, 11:50 UTC1h 20m
2026-07-21 VJT643 IBZ → CIA Jul 21, 07:55 UTCJul 21, 09:15 UTC1h 20m
2026-07-21 VJT643 - Jul 21, 05:30 UTCJul 21, 06:30 UTC1h 0m
2026-07-20 VJT643 NCE → TTU Jul 20, 13:25 UTCJul 20, 15:25 UTC2h 0m
2026-07-20 VJT643 - Jul 20, 10:30 UTCJul 20, 12:05 UTC1h 35m
2026-07-19 VJT643 - Jul 19, 08:25 UTCJul 19, 11:15 UTC2h 50m
2026-07-18 VJT643 - Jul 18, 13:05 UTCJul 18, 14:35 UTC1h 30m
2026-07-18 VJT643 - Jul 18, 10:15 UTCJul 18, 11:25 UTC1h 10m
2026-07-18 VJT643 - Jul 18, 07:05 UTCJul 18, 08:35 UTC1h 30m
2026-07-17 VJT643 - Jul 17, 08:40 UTCJul 17, 11:04 UTC2h 25m
2026-07-15 VJT643 JMK → FAB Jul 15, 12:00 UTCJul 15, 16:00 UTC4h 0m
2026-07-15 VJT643 ZRH → JMK Jul 15, 06:55 UTCJul 15, 09:05 UTC2h 10m
2026-07-15 VJT643 NCE → ZRH Jul 15, 04:20 UTCJul 15, 05:10 UTC50m
2026-07-14 VJT643 - Jul 14, 12:15 UTCJul 14, 13:20 UTC1h 5m
2026-07-14 VJT643 - Jul 14, 09:30 UTCJul 14, 10:50 UTC1h 20m
2026-07-14 VJT643 - Jul 14, 07:05 UTCJul 14, 08:05 UTC1h 0m
2026-07-13 VJT643 - Jul 13, 13:55 UTCJul 13, 14:55 UTC1h 0m
2026-07-13 VJT643 - Jul 13, 12:00 UTCJul 13, 12:15 UTC15m
2026-07-13 VJT643 - Jul 13, 09:45 UTCJul 13, 10:00 UTC15m
2026-07-13 VJT643 - Jul 13, 07:40 UTCJul 13, 08:30 UTC50m
2026-07-12 VJT643 - Jul 12, 18:01 UTCJul 12, 19:45 UTC1h 45m
2026-07-12 VJT643 - Jul 12, 14:25 UTCJul 12, 15:20 UTC55m
2026-07-12 VJT643 - Jul 12, 11:45 UTCJul 12, 13:05 UTC1h 20m
2026-07-11 VJT643 ACH → LBG Jul 11, 16:05 UTCJul 11, 17:05 UTC1h 0m
2026-07-11 VJT643 - Jul 11, 13:10 UTCJul 11, 15:30 UTC2h 20m
2026-07-10 VJT643 - Jul 10, 13:40 UTCJul 10, 14:25 UTC45m
2026-07-10 VJT643 BCN → CAT Jul 10, 10:35 UTCJul 10, 12:10 UTC1h 35m
2026-07-09 VJT643 - Jul 9, 17:30 UTCJul 9, 18:45 UTC1h 15m
2026-07-09 VJT978W - Jul 9, 13:25 UTCJul 9, 15:45 UTC2h 20m
2026-07-08 VJT643 - Jul 8, 15:20 UTCJul 8, 17:35 UTC2h 15m
2026-07-08 VJT643 - Jul 8, 13:50 UTCJul 8, 14:40 UTC50m
2026-07-08 VJT643 ZRH → GVA Jul 8, 12:20 UTCJul 8, 12:50 UTC30m
2026-07-07 VJT643 - Jul 7, 18:20 UTCJul 7, 18:50 UTC30m
2026-07-07 VJT643 - Jul 7, 15:45 UTCJul 7, 16:50 UTC1h 5m
2026-07-07 VJT643 NCE → FAB Jul 7, 11:15 UTCJul 7, 12:55 UTC1h 40m
2026-07-06 VJT643 - Jul 6, 15:10 UTCJul 6, 17:00 UTC1h 50m
2026-07-06 VJT643 - Jul 6, 11:35 UTCJul 6, 14:00 UTC2h 25m
2026-07-06 VJT643 - Jul 6, 09:30 UTCJul 6, 10:00 UTC30m
2026-07-04 VJT643 BCN → LTN Jul 4, 12:20 UTCJul 4, 14:10 UTC1h 50m
2026-07-04 VJT643 - Jul 4, 09:45 UTCJul 4, 10:10 UTC25m
2026-07-03 VJT643 - Jul 3, 10:30 UTCJul 3, 12:10 UTC1h 40m
2026-07-03 VJT643 - Jul 3, 07:15 UTCJul 3, 09:00 UTC1h 45m
2026-07-02 VJT643 - Jul 2, 16:15 UTCJul 2, 17:45 UTC1h 30m
2026-07-02 VJT643 FAO → CAT Jul 2, 13:55 UTCJul 2, 14:25 UTC30m

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 4D21CD frequently asked

What is Mode-S code 4D21CD?
4D21CD is an ICAO 24-bit transponder address. Allocated to Malta.
Where is Mode-S 4D21CD registered?
Mode-S code 4D21CD is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D21CD broadcasting right now?
No active broadcast right now. Last signal was 26d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D21CD, octal 23220715, decimal 5,054,925.
What flights does 4D21CD operate?
Mode-S 4D21CD has broadcast 5 distinct callsigns, including VJT643, VJT900W, VJT942W, VJT997W, VJT978W.