Apparatus

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sensors Mode-S transponder

4D21F6

ICAO 24-bit transponder address · allocated to Malta

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

Hex
4D21F6
Octal
23220766
Decimal
5,054,966
Country
MT
Tail
9H-CRI
Type
B738
Broadcasting now · callsign AEZ2348 · -50 ft
Flights observed
300
Distinct callsigns
20
Country
MT
Last broadcast
1h ago

Current position

4D21F6 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 4D21F6 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
AEZ31TR Aerial Transit Company 11 2026-05-28
AEZ2616 Aerial Transit Company 10 2026-05-27
AEZ139V Aerial Transit Company 10 2026-05-28
AEZ569P Aerial Transit Company 9 2026-05-25
AEZ49KF Aerial Transit Company 9 2026-05-12
AEZ2361 Aerial Transit Company 9 2026-05-12
AEZ2360 Aerial Transit Company 9 2026-05-07
AEZ318W Aerial Transit Company 8 2026-05-25
AEZ2367 Aerial Transit Company 8 2026-05-12
AEZ7813 Aerial Transit Company 7 2026-05-25
AEZ7117 - 7 2026-05-30
AEZ60RG Aerial Transit Company 7 2026-05-19
AEZ2617 Aerial Transit Company 7 2026-05-27
AEZ7817 Aerial Transit Company 6 2026-05-27
AEZ7814 Aerial Transit Company 6 2026-05-25
AEZ20GR Aerial Transit Company 6 2026-05-30
AEZ839Y Aerial Transit Company 5 2026-05-11
AEZ836S Aerial Transit Company 5 2026-05-12
AEZ70MH Aerial Transit Company 5 2026-05-07
AEZ500Q Aerial Transit Company 5 2026-05-29

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 AEZ2363 LIN → CAG May 30, 17:40 UTCMay 30, 18:35 UTC55m
2026-05-30 AEZ2362 CAG → LIN May 30, 15:20 UTCMay 30, 16:20 UTC1h 0m
2026-05-30 AEZ88LL LIN → CAG May 30, 13:10 UTCMay 30, 14:05 UTC55m
2026-05-30 AEZ47LG CAG → LIN May 30, 11:10 UTCMay 30, 12:15 UTC1h 5m
2026-05-30 AEZ7117 - May 30, 08:25 UTCMay 30, 09:00 UTC35m
2026-05-30 AEZ20GR CAG → FCO May 30, 06:25 UTCMay 30, 07:00 UTC35m
2026-05-29 AEZ7335 LIN → CAG May 29, 19:10 UTCMay 29, 20:00 UTC50m
2026-05-29 AEZ7330 OLB → LIN May 29, 16:50 UTCMay 29, 17:45 UTC55m
2026-05-29 AEZ7331 - May 29, 14:50 UTCMay 29, 15:45 UTC55m
2026-05-29 AEZ7334 CAG → LIN May 29, 12:25 UTCMay 29, 13:30 UTC1h 5m
2026-05-29 AEZ500Q FCO → CAG May 29, 10:10 UTCMay 29, 10:45 UTC35m
2026-05-29 AEZ40GR CAG → FCO May 29, 07:30 UTCMay 29, 08:10 UTC40m
2026-05-29 AEZ100N FCO → CAG May 29, 05:15 UTCMay 29, 05:50 UTC35m
2026-05-28 AEZ2348 CAG → FCO May 28, 19:50 UTCMay 28, 20:30 UTC40m
2026-05-28 AEZ11LJ FCO → CAG May 28, 17:55 UTCMay 28, 18:20 UTC25m
2026-05-28 AEZ11GR CAG → FCO May 28, 11:35 UTCMay 28, 12:15 UTC40m
2026-05-28 AEZ500Q FCO → CAG May 28, 09:50 UTCMay 28, 10:20 UTC30m
2026-05-28 AEZ31TR OLB → FCO May 28, 07:45 UTCMay 28, 08:20 UTC35m
2026-05-28 AEZ139V FCO → OLB May 28, 06:05 UTCMay 28, 06:25 UTC20m
2026-05-28 AEZ7810 OLB → FCO May 28, 04:10 UTCMay 28, 04:40 UTC30m
2026-05-27 AEZ2617 FCO → OLB May 27, 20:15 UTCMay 27, 20:35 UTC20m
2026-05-27 AEZ2616 OLB → FCO May 27, 18:25 UTCMay 27, 18:55 UTC30m
2026-05-27 AEZ7817 FCO → OLB May 27, 16:55 UTCMay 27, 17:25 UTC30m
2026-05-27 AEZ11GR CAG → FCO May 27, 11:35 UTCMay 27, 12:10 UTC35m
2026-05-27 AEZ500Q FCO → CAG May 27, 09:50 UTCMay 27, 10:20 UTC30m
2026-05-27 AEZ31TR OLB → FCO May 27, 07:40 UTCMay 27, 08:05 UTC25m
2026-05-27 AEZ139V FCO → OLB May 27, 05:59 UTCMay 27, 06:20 UTC20m
2026-05-27 AEZ7810 OLB → FCO May 27, 04:09 UTCMay 27, 04:39 UTC30m
2026-05-26 AEZ2617 FCO → OLB May 26, 20:20 UTCMay 26, 20:40 UTC20m
2026-05-26 AEZ2616 OLB → FCO May 26, 18:40 UTCMay 26, 19:15 UTC35m
2026-05-26 AEZ7817 FCO → OLB May 26, 17:04 UTCMay 26, 17:35 UTC30m
2026-05-26 AEZ22LO CAG → FCO May 26, 14:00 UTCMay 26, 14:35 UTC35m
2026-05-26 AEZ500Q FCO → CAG May 26, 09:45 UTCMay 26, 10:14 UTC30m
2026-05-26 AEZ31TR OLB → FCO May 26, 07:45 UTCMay 26, 08:10 UTC25m
2026-05-26 AEZ139V FCO → OLB May 26, 06:04 UTCMay 26, 06:25 UTC20m
2026-05-26 AEZ7810 OLB → FCO May 26, 04:15 UTCMay 26, 04:45 UTC30m
2026-05-25 AEZ2617 FCO → OLB May 25, 20:15 UTCMay 25, 20:34 UTC20m
2026-05-25 AEZ2616 OLB → FCO May 25, 18:30 UTCMay 25, 19:05 UTC35m
2026-05-25 AEZ7817 FCO → OLB May 25, 17:00 UTCMay 25, 17:20 UTC20m
2026-05-25 AEZ7814 OLB → FCO May 25, 15:25 UTCMay 25, 15:50 UTC25m
2026-05-25 AEZ569P FCO → OLB May 25, 13:35 UTCMay 25, 13:55 UTC20m
2026-05-25 AEZ318W OLB → FCO May 25, 11:35 UTCMay 25, 12:10 UTC35m
2026-05-25 AEZ7813 FCO → OLB May 25, 09:40 UTCMay 25, 10:10 UTC30m
2026-05-25 AEZ31TR OLB → FCO May 25, 07:45 UTCMay 25, 08:15 UTC30m
2026-05-25 AEZ139V FCO → OLB May 25, 06:10 UTCMay 25, 06:30 UTC20m
2026-05-25 AEZ2330 CAG → FCO May 25, 04:30 UTCMay 25, 05:05 UTC35m
2026-05-24 AEZ11LJ FCO → CAG May 24, 18:30 UTCMay 24, 19:00 UTC30m
2026-05-24 AEZ41GR CAG → FCO May 24, 16:30 UTCMay 24, 17:05 UTC35m
2026-05-24 AEZ811Z - May 24, 13:45 UTCMay 24, 14:10 UTC25m
2026-05-24 AEZ11GR CAG → FCO May 24, 11:30 UTCMay 24, 12:05 UTC35m

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

Mode-S 4D21F6 frequently asked

What is Mode-S code 4D21F6?
4D21F6 is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-CRI.
Where is Mode-S 4D21F6 registered?
Mode-S code 4D21F6 is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D21F6 broadcasting right now?
Yes. Mode-S 4D21F6 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D21F6, octal 23220766, decimal 5,054,966.
What flights does 4D21F6 operate?
Mode-S 4D21F6 has broadcast 20 distinct callsigns, including AEZ31TR, AEZ2616, AEZ139V, AEZ569P, AEZ49KF.