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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
Broadcasting now · callsign VJT643 · 18,000 ft
Flights observed
98
Distinct callsigns
4
Country
MT
Last broadcast
1h ago

Current position

4D21CD is currently broadcasting. Map zoomed to live position.

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 4 distinct

Callsign Airline Flights Last seen
VJT643 - 92 2026-07-07
VJT900W - 3 2026-06-26
VJT942W - 2 2026-05-30
VJT997W - 1 2026-06-21

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
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
2026-07-01 VJT643 - Jul 1, 20:00 UTCJul 1, 22:20 UTC2h 20m
2026-07-01 VJT643 - Jul 1, 16:55 UTCJul 1, 18:10 UTC1h 15m
2026-06-30 VJT643 AMS → FKB Jun 30, 17:50 UTCJun 30, 18:40 UTC50m
2026-06-30 VJT643 - Jun 30, 14:20 UTCJun 30, 17:10 UTC2h 50m
2026-06-30 VJT643 CAT → FAO Jun 30, 12:00 UTCJun 30, 12:30 UTC30m
2026-06-29 VJT643 - Jun 29, 15:09 UTCJun 29, 17:19 UTC2h 10m
2026-06-29 VJT643 - Jun 29, 11:35 UTCJun 29, 13:24 UTC1h 50m
2026-06-29 VJT643 - Jun 29, 08:04 UTCJun 29, 09:34 UTC1h 30m
2026-06-28 VJT643 - Jun 28, 11:04 UTCJun 28, 14:39 UTC3h 35m
2026-06-28 VJT643 - Jun 28, 07:29 UTCJun 28, 09:30 UTC2h 0m
2026-06-26 VJT900W STR → BUD Jun 26, 20:50 UTCJun 26, 21:59 UTC1h 10m
2026-06-26 VJT900W PRG → STR Jun 26, 14:39 UTCJun 26, 15:25 UTC45m
2026-06-26 VJT900W - Jun 26, 11:40 UTCJun 26, 12:55 UTC1h 15m
2026-06-23 VJT643 - Jun 23, 16:44 UTCJun 23, 18:04 UTC1h 20m
2026-06-23 VJT643 - Jun 23, 14:15 UTCJun 23, 15:30 UTC1h 15m
2026-06-23 VJT643 - Jun 23, 09:20 UTCJun 23, 12:55 UTC3h 35m
2026-06-22 VJT643 - Jun 22, 11:50 UTCJun 22, 13:35 UTC1h 45m
2026-06-22 VJT643 - Jun 22, 07:25 UTCJun 22, 08:54 UTC1h 30m
2026-06-21 VJT643 BQH → LBG Jun 21, 15:44 UTCJun 21, 16:30 UTC45m
2026-06-21 VJT643 - Jun 21, 13:09 UTCJun 21, 14:44 UTC1h 35m
2026-06-21 VJT643 - Jun 21, 10:34 UTCJun 21, 11:34 UTC1h 0m
2026-06-21 VJT997W - Jun 21, 09:00 UTCJun 21, 09:24 UTC25m
2026-06-20 VJT643 - Jun 20, 15:09 UTCJun 20, 16:05 UTC55m
2026-06-19 VJT643 - Jun 19, 19:25 UTCJun 19, 21:54 UTC2h 30m
2026-06-19 VJT643 - Jun 19, 17:09 UTCJun 19, 18:09 UTC1h 0m
2026-06-19 VJT643 - Jun 19, 12:59 UTCJun 19, 16:14 UTC3h 15m
2026-06-18 VJT643 ARN → FAB Jun 18, 13:40 UTCJun 18, 16:00 UTC2h 20m
2026-06-18 VJT643 - Jun 18, 11:15 UTCJun 18, 12:25 UTC1h 10m
2026-06-18 VJT643 - Jun 18, 09:40 UTCJun 18, 10:35 UTC55m
2026-06-17 VJT643 IBZ → FRA Jun 17, 13:25 UTCJun 17, 15:35 UTC2h 10m
2026-06-17 VJT643 - Jun 17, 09:25 UTCJun 17, 10:20 UTC55m
2026-06-16 VJT643 - Jun 16, 13:44 UTCJun 16, 15:40 UTC1h 55m
2026-06-16 VJT643 - Jun 16, 10:45 UTCJun 16, 12:14 UTC1h 30m
2026-06-15 VJT643 - Jun 15, 17:40 UTCJun 15, 18:04 UTC25m
2026-06-15 VJT643 - Jun 15, 15:10 UTCJun 15, 16:24 UTC1h 15m
2026-06-15 VJT643 - Jun 15, 12:45 UTCJun 15, 13:34 UTC50m
2026-06-15 VJT643 CAT → AMS Jun 15, 08:20 UTCJun 15, 10:55 UTC2h 35m
2026-06-14 VJT643 BCN → CAT Jun 14, 16:30 UTCJun 14, 18:05 UTC1h 35m
2026-06-14 VJT643 - Jun 14, 12:45 UTCJun 14, 14:55 UTC2h 10m

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?
Yes. Mode-S 4D21CD is currently airborne.
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 4 distinct callsigns, including VJT643, VJT900W, VJT942W, VJT997W.