sensors Mode-S transponder

0ACAC1

ICAO 24-bit transponder address · allocated to Costa Rica

Currently assigned to HK-5424 · AIRBUS A-320

Hex
0ACAC1
Octal
02545301
Decimal
707,265
Country
CR
Tail
HK-5424
Type
A320
No current signal · last broadcast 15m ago
Flights observed
6
Distinct callsigns
6
Country
CR
Last broadcast
15m ago

Last known position

Most recent position reported by Mode-S 0ACAC1.

Country allocation

The ICAO 24-bit address 0ACAC1 falls within the block assigned to Costa Rica (CR) by ICAO Annex 10, Volume III. Every aircraft registered in Costa Rica 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 6 distinct

Recent flights last 6

DateFlightRouteTakeoffLandingDuration
2026-04-21 AVA231 SJU → MDE Apr 21, 21:00 UTCApr 21, 22:15 UTC1h 15m
2026-04-21 AVA230 MDE → SJU Apr 21, 18:45 UTCApr 21, 19:00 UTC15m
2026-04-21 AVA235 MEX → MDE Apr 21, 11:25 UTCApr 21, 18:05 UTC6h 40m
2026-04-21 AVA234 MDE → MEX Apr 21, 07:20 UTCApr 21, 08:00 UTC40m
2026-04-20 AVA191 SJO → BOG Apr 20, 23:45 UTCApr 21, 06:45 UTC7h 0m
2026-04-20 AVA190 MDE → FLL Apr 20, 21:15 UTCApr 20, 21:55 UTC40m

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 HK-5424 page for operator, model, and routing details .

Mode-S 0ACAC1 frequently asked

What is Mode-S code 0ACAC1?
0ACAC1 is an ICAO 24-bit transponder address. Allocated to Costa Rica. Assigned to HK-5424.
Where is Mode-S 0ACAC1 registered?
Mode-S code 0ACAC1 is allocated to Costa Rica (CR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 0ACAC1 broadcasting right now?
No active broadcast right now. Last signal was 15m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 0ACAC1, octal 02545301, decimal 707,265.
What flights does 0ACAC1 operate?
Mode-S 0ACAC1 has broadcast 6 distinct callsigns, including AVA235, AVA234, AVA231, AVA230, AVA191.