sensors Mode-S transponder

71C277

ICAO 24-bit transponder address · allocated to Korea, South

Currently assigned to HL8277 · AIRBUS A-321

Hex
71C277
Octal
34341167
Decimal
7,455,351
Country
KR
Tail
HL8277
Type
A321
No current signal · last broadcast 2d ago
Flights observed
1
Distinct callsigns
1
Country
KR
Last broadcast
2d ago

Last known position

Most recent position reported by Mode-S 71C277.

Country allocation

The ICAO 24-bit address 71C277 falls within the block assigned to Korea, South (KR) by ICAO Annex 10, Volume III. Every aircraft registered in Korea, South 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
AAR708 Asiana Airlines 1 2026-04-12

Recent flights last 1

DateFlightRouteTakeoffLandingDuration
2026-04-12 AAR708 CRK → ICN Apr 12, 18:00 UTCApr 12, 19:35 UTC1h 35m

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 HL8277 page for operator, model, and routing details .

Mode-S 71C277 frequently asked

What is Mode-S code 71C277?
71C277 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8277.
Where is Mode-S 71C277 registered?
Mode-S code 71C277 is allocated to Korea, South (KR). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 71C277 broadcasting right now?
No active broadcast right now. Last signal was 2d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C277, octal 34341167, decimal 7,455,351.
What flights does 71C277 operate?
Mode-S 71C277 has broadcast 1 distinct callsign, including AAR708.