sensors Mode-S transponder

0AC3F9

ICAO 24-bit transponder address · allocated to Costa Rica

Currently assigned to HK-5294 · ATR-72-600

Hex
0AC3F9
Octal
02541771
Decimal
705,529
Country
CR
Tail
HK-5294
Type
AT76
No current signal · last broadcast 1d ago
Flights observed
11
Distinct callsigns
9
Country
CR
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 0AC3F9.

Country allocation

The ICAO 24-bit address 0AC3F9 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 9 distinct

Callsign Airline Flights Last seen
AVR4854 - 2 2026-04-13
AVR4824 - 2 2026-04-13
AVR5213 - 1 2026-04-13
AVR4895 - 1 2026-04-13
AVR4874 Avianca Express 1 2026-04-13
AVR4855 - 1 2026-04-13
AVR4829 - 1 2026-04-13
AVR4828 - 1 2026-04-13
AVR4827 - 1 2026-04-13

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-13 AVR4895 - Apr 13, 22:15 UTCApr 13, 22:25 UTC10m
2026-04-13 AVR4827 - Apr 13, 20:50 UTCApr 13, 21:15 UTC25m
2026-04-13 AVR4824 - Apr 13, 19:00 UTCApr 13, 19:15 UTC15m
2026-04-13 AVR4854 - Apr 13, 17:55 UTCApr 13, 18:05 UTC10m
2026-04-13 AVR4855 - Apr 13, 15:25 UTCApr 13, 15:40 UTC15m
2026-04-13 AVR4828 - Apr 13, 14:05 UTCApr 13, 14:20 UTC15m
2026-04-13 AVR4829 - Apr 13, 11:55 UTCApr 13, 12:15 UTC20m
2026-04-13 AVR5213 - Apr 13, 01:45 UTCApr 13, 02:00 UTC15m
2026-04-13 AVR4874 EYP → BOG Apr 13, 00:20 UTCApr 13, 00:45 UTC25m
2026-04-12 AVR4824 - Apr 12, 19:05 UTCApr 12, 19:15 UTC10m
2026-04-12 AVR4854 - Apr 12, 17:40 UTCApr 12, 17:55 UTC15m

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-5294 page for operator, model, and routing details .

Mode-S 0AC3F9 frequently asked

What is Mode-S code 0AC3F9?
0AC3F9 is an ICAO 24-bit transponder address. Allocated to Costa Rica. Assigned to HK-5294.
Where is Mode-S 0AC3F9 registered?
Mode-S code 0AC3F9 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 0AC3F9 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 0AC3F9, octal 02541771, decimal 705,529.
What flights does 0AC3F9 operate?
Mode-S 0AC3F9 has broadcast 9 distinct callsigns, including AVR4854, AVR4824, AVR5213, AVR4895, AVR4874.