sensors Mode-S transponder

501C55

ICAO 24-bit transponder address · allocated to Croatia

Currently assigned to 9A-BTM · AIRBUS A-320

Hex
501C55
Octal
24016125
Decimal
5,250,133
Country
HR
Tail
9A-BTM
Type
A320
No current signal · last broadcast 3h ago
Flights observed
5
Distinct callsigns
4
Country
HR
Last broadcast
3h ago

Last known position

Most recent position reported by Mode-S 501C55.

Country allocation

The ICAO 24-bit address 501C55 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 4 distinct

Callsign Airline Flights Last seen
ISR564 Israir Airlines 2 2026-05-09
TDR176 - 1 2026-04-18
ISR588 Israir Airlines 1 2026-05-10
ISR587 Israir Airlines 1 2026-05-10

Recent flights last 5

DateFlightRouteTakeoffLandingDuration
2026-05-10 ISR588 LCA → TLV May 10, 07:50 UTCMay 10, 08:30 UTC40m
2026-05-10 ISR587 TLV → LCA May 10, 05:45 UTCMay 10, 06:10 UTC25m
2026-05-09 ISR564 ATH → TLV May 9, 23:35 UTCMay 10, 01:09 UTC1h 35m
2026-05-09 ISR564 ATH → TLV May 9, 20:15 UTCMay 9, 21:50 UTC1h 35m
2026-04-18 TDR176 - Apr 18, 18:10 UTCApr 19, 02:35 UTC8h 25m

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

Mode-S 501C55 frequently asked

What is Mode-S code 501C55?
501C55 is an ICAO 24-bit transponder address. Allocated to Croatia. Assigned to 9A-BTM.
Where is Mode-S 501C55 registered?
Mode-S code 501C55 is allocated to Croatia (HR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 501C55 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 501C55, octal 24016125, decimal 5,250,133.
What flights does 501C55 operate?
Mode-S 501C55 has broadcast 4 distinct callsigns, including ISR564, TDR176, ISR588, ISR587.