sensors Mode-S transponder

4D21D4

ICAO 24-bit transponder address · allocated to Malta

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

Hex
4D21D4
Octal
23220724
Decimal
5,054,932
Country
MT
Tail
9H-TJB
Type
B738
No current signal · last broadcast 6h ago
Flights observed
74
Distinct callsigns
20
Country
MT
Last broadcast
6h ago

Last known position

Most recent position reported by Mode-S 4D21D4.

Country allocation

The ICAO 24-bit address 4D21D4 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
CAI3SD - 6 2026-04-15
CXI6F Shanxi Airlines 5 2026-05-29
CXI5RU - 5 2026-04-16
CXI4HL Shanxi Airlines 5 2026-05-29
CXI2FA - 5 2026-04-17
CXI9GQ - 3 2026-04-18
CXI8DF - 3 2026-05-29
CXI7W - 3 2026-04-13
CXI5ZQ - 3 2026-04-14
CXI3H - 3 2026-04-13
CAI9F - 3 2026-04-15
CXI6EY - 2 2026-04-16
CXI5CX - 2 2026-04-17
CXI3A - 2 2026-04-15
CXI19GZ - 2 2026-04-15
CXI9NM Shanxi Airlines 1 2026-05-27
CXI9N Shanxi Airlines 1 2026-05-28
CXI9MA Shanxi Airlines 1 2026-05-25
CXI9LU - 1 2026-04-18
CXI99TK Shanxi Airlines 1 2026-05-28

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 CXI4HL PMI → DUS May 29, 17:05 UTCMay 29, 19:10 UTC2h 5m
2026-05-29 CXI6F HER → BER May 29, 13:45 UTCMay 29, 15:35 UTC1h 50m
2026-05-29 CXI8DF - May 29, 09:20 UTCMay 29, 12:25 UTC3h 5m
2026-05-29 CXI16QB DUS → HER May 29, 04:50 UTCMay 29, 07:30 UTC2h 40m
2026-05-28 CXI99TK CFU → DUS May 28, 16:25 UTCMay 28, 18:50 UTC2h 25m
2026-05-28 CXI9N KGS → CGN May 28, 12:55 UTCMay 28, 14:50 UTC1h 55m
2026-05-28 CXI8DF - May 28, 08:25 UTCMay 28, 11:35 UTC3h 10m
2026-05-28 CXI8A DUS → HER May 28, 04:05 UTCMay 28, 06:45 UTC2h 40m
2026-05-27 CXI4HL PMI → DUS May 27, 17:15 UTCMay 27, 19:10 UTC1h 55m
2026-05-27 CXI6F HER → BER May 27, 14:05 UTCMay 27, 16:00 UTC1h 55m
2026-05-27 CXI3CA HRG → LEJ May 27, 09:20 UTCMay 27, 12:40 UTC3h 20m
2026-05-27 CXI9NM DUS → RHO May 27, 04:49 UTCMay 27, 07:55 UTC3h 5m
2026-05-26 CXI4HL PMI → DUS May 26, 17:20 UTCMay 26, 19:15 UTC1h 55m
2026-05-26 CXI6F HER → BER May 26, 13:54 UTCMay 26, 15:54 UTC2h 0m
2026-05-26 CAI1BF AYT → DUS May 26, 08:59 UTCMay 26, 12:24 UTC3h 25m
2026-05-26 CAI46NY DUS → AYT May 26, 04:24 UTCMay 26, 07:45 UTC3h 20m
2026-05-25 CXI4HL PMI → DUS May 25, 17:25 UTCMay 25, 19:25 UTC1h 59m
2026-05-25 CXI6F HER → BER May 25, 14:10 UTCMay 25, 16:10 UTC2h 0m
2026-05-25 CXI74KH HER → DUS May 25, 09:50 UTCMay 25, 12:45 UTC2h 55m
2026-05-25 CXI9MA DUS → HER May 25, 05:20 UTCMay 25, 08:15 UTC2h 55m
2026-05-24 CXI4HL PMI → DUS May 24, 16:50 UTCMay 24, 18:45 UTC1h 55m
2026-05-24 CXI6F HER → BER May 24, 13:30 UTCMay 24, 15:20 UTC1h 50m
2026-05-24 CXI8DF - May 24, 08:30 UTCMay 24, 11:30 UTC3h 0m
2026-05-24 CXI1KE DUS → HER May 24, 04:15 UTCMay 24, 07:00 UTC2h 45m
2026-05-23 CXI6HN HRG → DUS May 23, 07:25 UTCMay 23, 17:30 UTC10h 5m
2026-05-22 CXI077P - May 22, 16:05 UTCMay 22, 18:50 UTC2h 45m
2026-04-19 CXI079P - Apr 19, 18:10 UTCApr 19, 20:25 UTC2h 15m
2026-04-19 CXI8C - Apr 19, 14:45 UTCApr 19, 17:00 UTC2h 15m
2026-04-19 CXI2N HAJ → HAJ Apr 19, 11:10 UTCApr 19, 13:15 UTC2h 5m
2026-04-18 CXI17ED LPA → HAJ Apr 18, 19:00 UTCApr 18, 23:10 UTC4h 10m
2026-04-18 CXI9LU - Apr 18, 12:40 UTCApr 18, 17:15 UTC4h 35m
2026-04-18 CXI6D HER → HAJ Apr 18, 07:35 UTCApr 18, 10:40 UTC3h 5m
2026-04-18 CXI9GQ - Apr 18, 05:25 UTCApr 18, 06:05 UTC40m
2026-04-18 CXI9GQ - Apr 18, 04:45 UTCApr 18, 06:05 UTC1h 20m
2026-04-18 CXI9GQ - Apr 18, 03:25 UTCApr 18, 05:20 UTC1h 55m
2026-04-17 CXI5CX - Apr 17, 21:25 UTCApr 17, 22:25 UTC1h 0m
2026-04-17 CXI5CX - Apr 17, 19:45 UTCApr 17, 21:20 UTC1h 35m
2026-04-17 CXI2FA - Apr 17, 15:20 UTCApr 17, 16:05 UTC45m
2026-04-17 CXI2FA - Apr 17, 13:20 UTCApr 17, 15:15 UTC1h 54m
2026-04-17 CXI2FA - Apr 17, 12:55 UTCApr 17, 13:15 UTC20m
2026-04-16 CXI5RU - Apr 16, 09:10 UTCApr 16, 10:34 UTC1h 25m
2026-04-16 CXI5RU - Apr 16, 07:39 UTCApr 16, 09:05 UTC1h 25m
2026-04-16 CXI6EY - Apr 16, 05:09 UTCApr 16, 06:15 UTC1h 5m
2026-04-16 CXI6EY - Apr 16, 03:24 UTCApr 16, 05:05 UTC1h 40m
2026-04-15 CXI3A - Apr 15, 21:05 UTCApr 15, 22:30 UTC1h 25m
2026-04-15 CXI3A - Apr 15, 19:25 UTCApr 15, 21:00 UTC1h 35m
2026-04-15 CXI19GZ - Apr 15, 15:05 UTCApr 15, 16:50 UTC1h 45m
2026-04-15 CXI19GZ - Apr 15, 13:01 UTCApr 15, 14:55 UTC1h 54m
2026-04-15 CAI3SD - Apr 15, 11:00 UTCApr 15, 11:15 UTC15m
2026-04-15 CAI3SD - Apr 15, 09:00 UTCApr 15, 10:55 UTC1h 55m

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

Mode-S 4D21D4 frequently asked

What is Mode-S code 4D21D4?
4D21D4 is an ICAO 24-bit transponder address. Allocated to Malta. Assigned to 9H-TJB.
Where is Mode-S 4D21D4 registered?
Mode-S code 4D21D4 is allocated to Malta (MT). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 4D21D4 broadcasting right now?
No active broadcast right now. Last signal was 6h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 4D21D4, octal 23220724, decimal 5,054,932.
What flights does 4D21D4 operate?
Mode-S 4D21D4 has broadcast 20 distinct callsigns, including CAI3SD, CXI6F, CXI5RU, CXI4HL, CXI2FA.