sensors Mode-S transponder

0AC3D4

ICAO 24-bit transponder address · allocated to Costa Rica

Currently assigned to PNC-0242 · ATR-42-300

Hex
0AC3D4
Octal
02541724
Decimal
705,492
Country
CR
Tail
PNC-0242
Type
AT43
No current signal · last broadcast 3h ago
Flights observed
9
Distinct callsigns
1
Country
CR
Last broadcast
3h ago

Last known position

Most recent position reported by Mode-S 0AC3D4.

Country allocation

The ICAO 24-bit address 0AC3D4 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 1 distinct

Callsign Airline Flights Last seen
PNC0242 - 9 2026-05-20

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-05-20 PNC0242 - May 20, 18:15 UTCMay 20, 18:25 UTC10m
2026-05-20 PNC0242 - May 20, 16:50 UTCMay 20, 17:00 UTC10m
2026-05-20 PNC0242 - May 20, 11:25 UTCMay 20, 11:35 UTC10m
2026-05-18 PNC0242 - May 18, 17:40 UTCMay 18, 17:55 UTC15m
2026-05-18 PNC0242 - May 18, 11:50 UTCMay 18, 12:05 UTC15m
2026-05-17 PNC0242 - May 17, 22:50 UTCMay 17, 23:10 UTC20m
2026-05-17 PNC0242 - May 17, 18:01 UTCMay 17, 18:15 UTC15m
2026-05-16 PNC0242 - May 16, 21:50 UTCMay 16, 22:10 UTC20m
2026-05-16 PNC0242 - May 16, 20:15 UTCMay 16, 20:35 UTC20m

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 PNC-0242 page for operator, model, and routing details .

Mode-S 0AC3D4 frequently asked

What is Mode-S code 0AC3D4?
0AC3D4 is an ICAO 24-bit transponder address. Allocated to Costa Rica. Assigned to PNC-0242.
Where is Mode-S 0AC3D4 registered?
Mode-S code 0AC3D4 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 0AC3D4 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 0AC3D4, octal 02541724, decimal 705,492.
What flights does 0AC3D4 operate?
Mode-S 0AC3D4 has broadcast 1 distinct callsign, including PNC0242.