sensors Mode-S transponder

0AC9BD

ICAO 24-bit transponder address · allocated to Costa Rica

Currently assigned to HK-5351 · ATR-42-600

Hex
0AC9BD
Octal
02544675
Decimal
707,005
Country
CR
Tail
HK-5351
Type
AT46
No current signal · last broadcast 12h ago
Flights observed
12
Distinct callsigns
12
Country
CR
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 0AC9BD.

Country allocation

The ICAO 24-bit address 0AC9BD 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 12 distinct

Callsign Airline Flights Last seen
EFY9105 - 1 2026-04-13
EFY9104 - 1 2026-04-13
EFY9045 - 1 2026-04-13
EFY9044 - 1 2026-04-13
EFY9039 EasyFly 1 2026-04-13
EFY9035 - 1 2026-04-13
EFY9034 - 1 2026-04-13
EFY9031 - 1 2026-04-12
EFY9020 - 1 2026-04-12
EFY7839 - 1 2026-04-13
EFY7838 - 1 2026-04-13
EFY6978 - 1 2026-04-14

Recent flights last 12

DateFlightRouteTakeoffLandingDuration
2026-04-14 EFY6978 - Apr 14, 10:55 UTCApr 14, 11:05 UTC10m
2026-04-13 EFY7839 - Apr 13, 23:10 UTCApr 13, 23:25 UTC15m
2026-04-13 EFY7838 - Apr 13, 21:40 UTCApr 13, 21:55 UTC15m
2026-04-13 EFY9045 - Apr 13, 20:00 UTCApr 13, 20:10 UTC10m
2026-04-13 EFY9044 - Apr 13, 17:55 UTCApr 13, 18:10 UTC15m
2026-04-13 EFY9035 - Apr 13, 16:30 UTCApr 13, 16:50 UTC20m
2026-04-13 EFY9034 - Apr 13, 14:00 UTCApr 13, 14:20 UTC20m
2026-04-13 EFY9105 - Apr 13, 12:35 UTCApr 13, 12:45 UTC10m
2026-04-13 EFY9104 - Apr 13, 10:50 UTCApr 13, 11:10 UTC20m
2026-04-13 EFY9039 FLA → BOG Apr 13, 01:15 UTCApr 13, 01:35 UTC20m
2026-04-12 EFY9020 - Apr 12, 19:05 UTCApr 12, 19:20 UTC15m
2026-04-12 EFY9031 GIR → BOG Apr 12, 17:55 UTCApr 12, 18:15 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 HK-5351 page for operator, model, and routing details .

Mode-S 0AC9BD frequently asked

What is Mode-S code 0AC9BD?
0AC9BD is an ICAO 24-bit transponder address. Allocated to Costa Rica. Assigned to HK-5351.
Where is Mode-S 0AC9BD registered?
Mode-S code 0AC9BD 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 0AC9BD broadcasting right now?
No active broadcast right now. Last signal was 12h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 0AC9BD, octal 02544675, decimal 707,005.
What flights does 0AC9BD operate?
Mode-S 0AC9BD has broadcast 12 distinct callsigns, including EFY9105, EFY9104, EFY9045, EFY9044, EFY9039.