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sensors Mode-S transponder

501DD0

ICAO 24-bit transponder address · allocated to Croatia

Currently assigned to 9A-CQE · DE HAVILLAND DHC-8-400 Dash 8

Hex
501DD0
Octal
24016720
Decimal
5,250,512
Country
HR
Tail
9A-CQE
Type
DH8D
No current signal · last broadcast Jul 26, 20:45 UTC
Flights observed
664
Distinct callsigns
20
Country
HR
Last broadcast
Jul 26, 20:45 UTC

Last known position

Most recent position reported by Mode-S 501DD0.

Country allocation

The ICAO 24-bit address 501DD0 falls within the block assigned to Croatia (HR) by ICAO Annex 10, Volume III. Every aircraft registered in Croatia 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
CTN344 Croatia Airlines 42 2026-07-26
CTN345 Croatia Airlines 41 2026-07-26
CTN4AT Croatia Airlines 36 2026-07-24
CTN441 Croatia Airlines 35 2026-07-24
CTN3T Croatia Airlines 34 2026-07-21
CTN632 - 31 2026-07-20
CTN6CH - 26 2026-07-24
CTN465 Croatia Airlines 26 2026-07-24
CTN443 Croatia Airlines 25 2026-07-20
CTN442 - 23 2026-07-20
CTN342 Croatia Airlines 18 2026-07-26
CTN437 - 17 2026-07-15
CTN436 - 17 2026-07-15
CTN341 - 17 2026-07-22
CTN4W Croatia Airlines 16 2026-07-13
CTN436R Croatia Airlines 15 2026-07-20
CTN4437 - 14 2026-07-20
CTN327 Croatia Airlines 13 2026-07-24
CTN326 Croatia Airlines 13 2026-07-23
CTN641 Croatia Airlines 11 2026-07-25

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 CTN342 ZAG → SJJ Jul 26, 20:20 UTCJul 26, 20:45 UTC25m
2026-07-26 CTN5R SPU → ZAG Jul 26, 17:30 UTCJul 26, 17:50 UTC20m
2026-07-26 CTN654 ZAG → SPU Jul 26, 16:00 UTCJul 26, 16:20 UTC20m
2026-07-26 CTN345 SJJ → ZAG Jul 26, 14:20 UTCJul 26, 14:50 UTC30m
2026-07-26 CTN344 ZAG → SJJ Jul 26, 12:55 UTCJul 26, 13:15 UTC20m
2026-07-26 CTN461 ZRH → ZAG Jul 26, 09:55 UTCJul 26, 11:10 UTC1h 15m
2026-07-26 CTN460 ZAG → ZRH Jul 26, 07:25 UTCJul 26, 08:35 UTC1h 10m
2026-07-25 CTN641 BWK → ZAG Jul 25, 15:25 UTCJul 25, 15:45 UTC20m
2026-07-25 CTN245T - Jul 25, 13:20 UTCJul 25, 14:00 UTC40m
2026-07-25 CTN442T - Jul 25, 11:45 UTCJul 25, 12:35 UTC50m
2026-07-25 CTN2449 - Jul 25, 09:40 UTCJul 25, 10:40 UTC1h 0m
2026-07-25 CTN2448 - Jul 25, 07:50 UTCJul 25, 08:55 UTC1h 5m
2026-07-25 CTN640 ZAG → BWK Jul 25, 06:10 UTCJul 25, 06:25 UTC15m
2026-07-24 CTN465 ZRH → ZAG Jul 24, 18:15 UTCJul 24, 19:15 UTC1h 0m
2026-07-24 CTN6CH - Jul 24, 16:10 UTCJul 24, 17:25 UTC1h 15m
2026-07-24 CTN345 SJJ → ZAG Jul 24, 14:30 UTCJul 24, 15:00 UTC30m
2026-07-24 CTN344 - Jul 24, 13:20 UTCJul 24, 13:45 UTC25m
2026-07-24 CTN5N - Jul 24, 11:45 UTCJul 24, 11:55 UTC10m
2026-07-24 CTN2S ZAG → SPU Jul 24, 10:00 UTCJul 24, 10:15 UTC15m
2026-07-24 CTN441 VIE → ZAG Jul 24, 08:00 UTCJul 24, 08:35 UTC35m
2026-07-24 CTN4AT ZAG → VIE Jul 24, 06:10 UTCJul 24, 06:40 UTC30m
2026-07-24 CTN327 OMO → ZAG Jul 24, 04:15 UTCJul 24, 04:45 UTC30m
2026-07-23 CTN326 ZAG → OMO Jul 23, 21:10 UTCJul 23, 21:40 UTC30m
2026-07-23 CTN465 ZRH → ZAG Jul 23, 18:15 UTCJul 23, 19:20 UTC1h 5m
2026-07-23 CTN6CH - Jul 23, 16:05 UTCJul 23, 17:20 UTC1h 15m
2026-07-23 CTN345 SJJ → ZAG Jul 23, 14:25 UTCJul 23, 14:55 UTC30m
2026-07-23 CTN344 - Jul 23, 13:10 UTCJul 23, 13:35 UTC25m
2026-07-23 CTN441 VIE → ZAG Jul 23, 07:55 UTCJul 23, 08:25 UTC30m
2026-07-23 CTN4AT ZAG → VIE Jul 23, 06:20 UTCJul 23, 06:55 UTC35m
2026-07-22 CTN415 FRA → ZAG Jul 22, 19:10 UTCJul 22, 20:20 UTC1h 10m
2026-07-22 CTN414 - Jul 22, 16:05 UTCJul 22, 17:35 UTC1h 30m
2026-07-22 CTN345 SJJ → ZAG Jul 22, 14:25 UTCJul 22, 14:55 UTC30m
2026-07-22 CTN344 - Jul 22, 13:10 UTCJul 22, 13:35 UTC25m
2026-07-22 CTN341 - Jul 22, 05:05 UTCJul 22, 05:25 UTC20m
2026-07-21 CTN342 ZAG → SJJ Jul 21, 20:40 UTCJul 21, 21:10 UTC30m
2026-07-21 CTN465 ZRH → ZAG Jul 21, 18:25 UTCJul 21, 19:25 UTC1h 0m
2026-07-21 CTN6CH - Jul 21, 16:10 UTCJul 21, 17:25 UTC1h 15m
2026-07-21 CTN345 SJJ → ZAG Jul 21, 14:20 UTCJul 21, 14:55 UTC35m
2026-07-21 CTN344 - Jul 21, 13:05 UTCJul 21, 13:35 UTC30m
2026-07-21 CTN6X - Jul 21, 11:10 UTCJul 21, 12:00 UTC50m
2026-07-21 CTN660 ZAG → DBV Jul 21, 09:25 UTCJul 21, 10:20 UTC55m
2026-07-21 CTN441 - Jul 21, 07:55 UTCJul 21, 08:25 UTC30m
2026-07-21 CTN4AT - Jul 21, 06:10 UTCJul 21, 06:45 UTC35m
2026-07-21 CTN3T PUY → ZAG Jul 21, 05:05 UTCJul 21, 05:15 UTC10m
2026-07-20 CTN632 - Jul 20, 20:40 UTCJul 20, 20:55 UTC15m
2026-07-20 CTN632 - Jul 20, 19:35 UTCJul 20, 19:55 UTC20m
2026-07-20 CTN443 VIE → ZAG Jul 20, 17:50 UTCJul 20, 18:25 UTC35m
2026-07-20 CTN442 - Jul 20, 16:05 UTCJul 20, 16:35 UTC30m
2026-07-20 CTN345 SJJ → ZAG Jul 20, 14:40 UTCJul 20, 15:10 UTC30m
2026-07-20 CTN344 - Jul 20, 13:35 UTCJul 20, 14:00 UTC25m

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 9A-CQE page for operator, model, and routing details .

Mode-S 501DD0 frequently asked

What is Mode-S code 501DD0?
501DD0 is an ICAO 24-bit transponder address. Allocated to Croatia. Assigned to 9A-CQE.
Where is Mode-S 501DD0 registered?
Mode-S code 501DD0 is allocated to Croatia (HR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 501DD0 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 20:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 501DD0, octal 24016720, decimal 5,250,512.
What flights does 501DD0 operate?
Mode-S 501DD0 has broadcast 20 distinct callsigns, including CTN344, CTN345, CTN4AT, CTN441, CTN3T.