Apparatus

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sensors Mode-S transponder

4D21D2

ICAO 24-bit transponder address · allocated to Malta

Currently assigned to 9H-GFP · BOEING 737-800

Hex
4D21D2
Octal
23220722
Decimal
5,054,930
Country
MT
Tail
9H-GFP
Type
B738
No current signal · last broadcast 3h ago
Flights observed
600
Distinct callsigns
20
Country
MT
Last broadcast
3h ago

Last known position

Most recent position reported by Mode-S 4D21D2.

Country allocation

The ICAO 24-bit address 4D21D2 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
AEZ836S - 17 2026-07-05
AEZ569P - 16 2026-07-12
AEZ389L - 16 2026-07-05
AEZ7814 - 15 2026-06-30
AEZ839Y - 14 2026-07-13
AEZ835L Aerial Transit Company 14 2026-07-05
AEZ385Z - 14 2026-07-13
AEZ29JD Aerial Transit Company 14 2026-07-05
AEZ2617 - 14 2026-07-12
AEZ833J Aerial Transit Company 13 2026-07-05
AEZ413P Aerial Transit Company 13 2026-06-17
AEZ38TM - 13 2026-07-05
AEZ141W Aerial Transit Company 13 2026-06-17
AEZ419P Aerial Transit Company 12 2026-06-17
AEZ418P Aerial Transit Company 12 2026-06-16
AEZ146R Aerial Transit Company 12 2026-06-16
AEZ139V - 12 2026-07-12
AEZ60RG - 11 2026-07-03
AEZ318W - 11 2026-07-07
AEZ2616 - 11 2026-06-30

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 AEZ2631 LIN → OLB Jul 14, 14:20 UTCJul 14, 15:20 UTC1h 0m
2026-07-14 AEZ2630 - Jul 14, 12:20 UTCJul 14, 13:05 UTC45m
2026-07-14 AEZ2629 LIN → OLB Jul 14, 09:35 UTCJul 14, 10:35 UTC1h 0m
2026-07-14 AEZ2628 - Jul 14, 07:25 UTCJul 14, 08:15 UTC50m
2026-07-13 AEZ839Y - Jul 13, 18:40 UTCJul 13, 20:00 UTC1h 20m
2026-07-13 AEZ385Z OLB → LIN Jul 13, 17:10 UTCJul 13, 18:05 UTC55m
2026-07-13 AEZ2631 LIN → OLB Jul 13, 14:20 UTCJul 13, 15:15 UTC55m
2026-07-13 AEZ2630 - Jul 13, 12:10 UTCJul 13, 12:55 UTC45m
2026-07-13 AEZ2629 - Jul 13, 09:20 UTCJul 13, 10:10 UTC50m
2026-07-13 AEZ2628 - Jul 13, 07:15 UTCJul 13, 08:05 UTC50m
2026-07-12 AEZ2617 - Jul 12, 19:40 UTCJul 12, 20:10 UTC30m
2026-07-12 AEZ7816 OLB → FCO Jul 12, 17:55 UTCJul 12, 18:30 UTC35m
2026-07-12 AEZ569P - Jul 12, 16:10 UTCJul 12, 16:45 UTC35m
2026-07-12 AEZ311L OLB → FCO Jul 12, 14:45 UTCJul 12, 15:15 UTC30m
2026-07-12 AEZ131R FCO → OLB Jul 12, 12:45 UTCJul 12, 13:15 UTC30m
2026-07-12 AEZ7812 - Jul 12, 11:25 UTCJul 12, 11:50 UTC25m
2026-07-12 AEZ139V - Jul 12, 09:45 UTCJul 12, 10:15 UTC30m
2026-07-12 AEZ7810 - Jul 12, 08:10 UTCJul 12, 08:35 UTC25m
2026-07-11 AEZ2617 - Jul 11, 23:05 UTCJul 11, 23:35 UTC30m
2026-07-11 AEZ7816 OLB → FCO Jul 11, 21:55 UTCJul 11, 22:25 UTC30m
2026-07-11 AEZ2631 LIN → OLB Jul 11, 20:35 UTCJul 11, 20:55 UTC20m
2026-07-11 AEZ2631 LIN → OLB Jul 11, 14:25 UTCJul 11, 15:45 UTC1h 20m
2026-07-11 AEZ2630 - Jul 11, 12:10 UTCJul 11, 12:55 UTC45m
2026-07-11 AEZ2629 LIN → OLB Jul 11, 09:10 UTCJul 11, 10:10 UTC1h 0m
2026-07-11 AEZ2628 - Jul 11, 07:15 UTCJul 11, 07:50 UTC35m
2026-07-10 AEZ839Y LIN → OLB Jul 10, 19:20 UTCJul 10, 20:15 UTC55m
2026-07-10 AEZ385Z - Jul 10, 17:10 UTCJul 10, 17:55 UTC45m
2026-07-10 AEZ2631 LIN → OLB Jul 10, 14:30 UTCJul 10, 15:30 UTC1h 0m
2026-07-10 AEZ2630 - Jul 10, 12:15 UTCJul 10, 13:05 UTC50m
2026-07-10 AEZ2629 - Jul 10, 09:15 UTCJul 10, 10:10 UTC55m
2026-07-10 AEZ2628 - Jul 10, 07:05 UTCJul 10, 07:55 UTC50m
2026-07-09 AEZ2617 - Jul 9, 19:45 UTCJul 9, 20:15 UTC30m
2026-07-09 AEZ7816 OLB → FCO Jul 9, 17:55 UTCJul 9, 18:25 UTC30m
2026-07-09 AEZ569P - Jul 9, 15:55 UTCJul 9, 16:20 UTC25m
2026-07-09 AEZ7812 - Jul 9, 09:30 UTCJul 9, 10:05 UTC35m
2026-07-09 AEZ139V - Jul 9, 07:50 UTCJul 9, 08:20 UTC30m
2026-07-09 AEZ20GR - Jul 9, 05:55 UTCJul 9, 06:35 UTC40m
2026-07-08 AEZ2363 - Jul 8, 17:35 UTCJul 8, 18:40 UTC1h 5m
2026-07-08 AEZ14UJ - Jul 8, 14:55 UTCJul 8, 16:00 UTC1h 5m
2026-07-08 AEZ8094 - Jul 8, 08:35 UTCJul 8, 09:40 UTC1h 5m
2026-07-08 AEZ44LG - Jul 8, 06:20 UTCJul 8, 07:15 UTC55m
2026-07-07 AEZ11LJ FCO → CAG Jul 7, 16:40 UTCJul 7, 17:20 UTC40m
2026-07-07 AEZ318W - Jul 7, 11:35 UTCJul 7, 12:10 UTC35m
2026-07-07 AEZ7813 - Jul 7, 09:55 UTCJul 7, 10:25 UTC30m
2026-07-07 AEZ31TR - Jul 7, 07:35 UTCJul 7, 08:10 UTC35m
2026-07-07 AEZ7811 - Jul 7, 05:55 UTCJul 7, 06:25 UTC30m
2026-07-06 AEZ514C - Jul 6, 19:30 UTCJul 6, 20:25 UTC55m
2026-07-06 AEZ155Z - Jul 6, 15:10 UTCJul 6, 16:45 UTC1h 35m
2026-07-06 AEZ7812 - Jul 6, 10:00 UTCJul 6, 10:35 UTC35m
2026-07-06 AEZ139V - Jul 6, 08:10 UTCJul 6, 08:40 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.

Prefer a tail-number view? See the 9H-GFP page for operator, model, and routing details .

Mode-S 4D21D2 frequently asked

What is Mode-S code 4D21D2?
4D21D2 is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-GFP.
Where is Mode-S 4D21D2 registered?
Mode-S code 4D21D2 is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D21D2 broadcasting right now?
No active broadcast right now. Last signal was 3h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D21D2, octal 23220722, decimal 5,054,930.
What flights does 4D21D2 operate?
Mode-S 4D21D2 has broadcast 20 distinct callsigns, including AEZ836S, AEZ569P, AEZ389L, AEZ7814, AEZ839Y.