sensors Mode-S transponder

501D1D

ICAO 24-bit transponder address · allocated to Croatia

Currently assigned to 9A-CTH · AIRBUS A-319

Hex
501D1D
Octal
24016435
Decimal
5,250,333
Country
HR
Tail
9A-CTH
Type
A319
No current signal · last broadcast 7h ago
Flights observed
271
Distinct callsigns
20
Country
HR
Last broadcast
7h ago

Last known position

Most recent position reported by Mode-S 501D1D.

Country allocation

The ICAO 24-bit address 501D1D 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

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 CTN4409 BER → ZAG May 29, 21:10 UTCMay 29, 22:10 UTC1h 0m
2026-05-29 CTN4408 ZAG → BER May 29, 18:55 UTCMay 29, 20:10 UTC1h 15m
2026-05-29 CTN19H FRA → ZAG May 29, 16:35 UTCMay 29, 17:35 UTC1h 0m
2026-05-29 CTN412 SPU → FRA May 29, 12:55 UTCMay 29, 14:20 UTC1h 25m
2026-05-29 CTN413 FRA → SPU May 29, 10:25 UTCMay 29, 11:30 UTC1h 5m
2026-05-29 CTN416 ZAG → FRA May 29, 07:20 UTCMay 29, 08:25 UTC1h 5m
2026-05-28 CTN301 ATH → DBV May 28, 21:25 UTCMay 28, 22:00 UTC35m
2026-05-28 CTN301 ATH → DBV May 28, 19:10 UTCMay 28, 20:25 UTC1h 15m
2026-05-28 CTN3RC DBV → ATH May 28, 16:50 UTCMay 28, 18:00 UTC1h 10m
2026-05-28 CTN3RC DBV → ATH May 28, 15:20 UTCMay 28, 16:00 UTC40m
2026-05-28 CTN2S ZAG → SPU May 28, 11:00 UTCMay 28, 11:15 UTC15m
2026-05-28 CTN9HR FRA → ZAG May 28, 08:55 UTCMay 28, 09:50 UTC55m
2026-05-28 CTN410 ZAG → FRA May 28, 05:50 UTCMay 28, 07:05 UTC1h 15m
2026-05-27 CTN415 FRA → ZAG May 27, 19:20 UTCMay 27, 20:20 UTC1h 0m
2026-05-27 CTN414 ZAG → FRA May 27, 16:20 UTCMay 27, 17:40 UTC1h 20m
2026-05-27 CTN6D DBV → ZAG May 27, 11:00 UTCMay 27, 11:45 UTC45m
2026-05-27 CTN27H FRA → DBV May 27, 08:50 UTCMay 27, 10:20 UTC1h 30m
2026-05-27 CTN27D DBV → FRA May 27, 05:35 UTCMay 27, 07:20 UTC1h 46m
2026-05-26 CTN756C ZRH → DBV May 26, 13:50 UTCMay 26, 15:14 UTC1h 25m
2026-05-26 CTN756R DBV → ZRH May 26, 11:24 UTCMay 26, 12:45 UTC1h 20m
2026-05-26 CTN27H FRA → DBV May 26, 08:39 UTCMay 26, 10:10 UTC1h 30m
2026-05-26 CTN27D DBV → FRA May 26, 05:40 UTCMay 26, 07:19 UTC1h 40m
2026-05-25 CTN4429 STR → DBV May 25, 18:50 UTCMay 25, 20:09 UTC1h 19m
2026-05-25 CTN4428 DBV → STR May 25, 16:30 UTCMay 25, 18:00 UTC1h 30m
2026-05-25 CTN756C ZRH → DBV May 25, 14:05 UTCMay 25, 15:30 UTC1h 25m
2026-05-25 CTN756R DBV → ZRH May 25, 11:30 UTCMay 25, 13:05 UTC1h 35m
2026-05-25 CTN27H FRA → DBV May 25, 09:00 UTCMay 25, 10:35 UTC1h 35m
2026-05-25 CTN27D DBV → FRA May 25, 05:35 UTCMay 25, 07:15 UTC1h 40m
2026-05-24 CTN29F CDG → DBV May 24, 15:15 UTCMay 24, 17:20 UTC2h 5m
2026-05-24 CTN476 DBV → CDG May 24, 12:00 UTCMay 24, 14:00 UTC2h 0m
2026-05-24 CTN27H FRA → DBV May 24, 09:30 UTCMay 24, 11:00 UTC1h 30m
2026-05-24 CTN416 ZAG → FRA May 24, 06:50 UTCMay 24, 08:00 UTC1h 10m
2026-05-23 CTN19H FRA → ZAG May 23, 14:20 UTCMay 23, 15:15 UTC55m
2026-05-23 CTN412 SPU → FRA May 23, 11:35 UTCMay 23, 12:55 UTC1h 20m
2026-05-23 CTN423 DUS → SPU May 23, 08:55 UTCMay 23, 10:15 UTC1h 20m
2026-05-23 CTN422 SPU → DUS May 23, 06:15 UTCMay 23, 07:45 UTC1h 30m
2026-05-23 CTN1W ZAG → SPU May 23, 04:30 UTCMay 23, 04:45 UTC15m
2026-05-22 CTN4409 BER → ZAG May 22, 21:10 UTCMay 22, 22:10 UTC1h 0m
2026-05-22 CTN4408 ZAG → BER May 22, 18:35 UTCMay 22, 19:50 UTC1h 15m
2026-05-22 CTN19H FRA → ZAG May 22, 16:25 UTCMay 22, 17:25 UTC1h 0m
2026-05-22 CTN412 SPU → FRA May 22, 13:15 UTCMay 22, 14:40 UTC1h 25m
2026-05-22 CTN413 FRA → SPU May 22, 10:20 UTCMay 22, 11:25 UTC1h 5m
2026-05-22 CTN416 ZAG → FRA May 22, 07:10 UTCMay 22, 08:20 UTC1h 10m
2026-05-21 CTN71F CDG → ZAG May 21, 17:00 UTCMay 21, 18:20 UTC1h 20m
2026-05-21 CTN476 DBV → CDG May 21, 13:25 UTCMay 21, 15:35 UTC2h 10m
2026-05-21 CTN29F CDG → DBV May 21, 10:35 UTCMay 21, 12:25 UTC1h 50m
2026-05-21 CTN25F ZAG → CDG May 21, 07:10 UTCMay 21, 08:50 UTC1h 40m
2026-05-21 CTN5H SPU → ZAG May 21, 04:30 UTCMay 21, 04:40 UTC10m
2026-05-20 CTN4357 - May 20, 18:50 UTCMay 20, 20:05 UTC1h 15m
2026-05-20 CTN4356 - May 20, 16:05 UTCMay 20, 17:15 UTC1h 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.

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

Mode-S 501D1D frequently asked

What is Mode-S code 501D1D?
501D1D is an ICAO 24-bit transponder address. Allocated to Croatia. Assigned to 9A-CTH.
Where is Mode-S 501D1D registered?
Mode-S code 501D1D is allocated to Croatia (HR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 501D1D broadcasting right now?
No active broadcast right now. Last signal was 7h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 501D1D, octal 24016435, decimal 5,250,333.
What flights does 501D1D operate?
Mode-S 501D1D has broadcast 20 distinct callsigns, including CTN5H, CTN414, CTN412, CTN9HR, CTN460.