Apparatus

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sensors Mode-S transponder

0AC9B7

ICAO 24-bit transponder address · allocated to Costa Rica

Currently assigned to HK-2978G · PIPER PA-28-140/150/160/180

Hex
0AC9B7
Octal
02544667
Decimal
706,999
Country
CR
Tail
HK-2978G
Type
P28A
No current signal · last broadcast 1d ago
Flights observed
8
Distinct callsigns
1
Country
CR
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 0AC9B7.

Country allocation

The ICAO 24-bit address 0AC9B7 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
HK2978G - 8 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-13 HK2978G - Apr 13, 20:25 UTCApr 13, 21:05 UTC40m
2026-04-13 HK2978G - Apr 13, 19:10 UTCApr 13, 19:45 UTC35m
2026-04-13 HK2978G - Apr 13, 17:40 UTCApr 13, 18:05 UTC25m
2026-04-13 HK2978G - Apr 13, 16:20 UTCApr 13, 16:35 UTC15m
2026-04-13 HK2978G - Apr 13, 15:50 UTCApr 13, 16:35 UTC45m
2026-04-13 HK2978G - Apr 13, 15:30 UTCApr 13, 15:55 UTC25m
2026-04-13 HK2978G - Apr 13, 13:45 UTCApr 13, 14:00 UTC15m
2026-04-12 HK2978G - Apr 12, 17:20 UTCApr 12, 17:50 UTC30m

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-2978G page for operator, model, and routing details .

Mode-S 0AC9B7 frequently asked

What is Mode-S code 0AC9B7?
0AC9B7 is an ICAO 24-bit transponder address. Allocated to Costa Rica. Assigned to HK-2978G.
Where is Mode-S 0AC9B7 registered?
Mode-S code 0AC9B7 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 0AC9B7 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 0AC9B7, octal 02544667, decimal 706,999.
What flights does 0AC9B7 operate?
Mode-S 0AC9B7 has broadcast 1 distinct callsign, including HK2978G.