sensors Mode-S transponder

71C561

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

Currently assigned to HL8561 · AIRBUS A-330-300

Hex
71C561
Octal
34342541
Decimal
7,456,097
Country
KR
Tail
HL8561
Type
A333
No current signal · last broadcast 19h ago
Flights observed
7
Distinct callsigns
2
Country
KR
Last broadcast
19h ago

Last known position

Most recent position reported by Mode-S 71C561.

Country allocation

The ICAO 24-bit address 71C561 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 2 distinct

Callsign Airline Flights Last seen
TWB161 - 4 2026-04-14
TWB162 Tway Airlines 3 2026-04-13

Recent flights last 7

DateFlightRouteTakeoffLandingDuration
2026-04-14 TWB161 - Apr 14, 09:10 UTCApr 14, 09:55 UTC45m
2026-04-14 TWB161 - Apr 14, 07:10 UTCApr 14, 09:05 UTC1h 55m
2026-04-13 TWB162 SIN → ICN Apr 13, 20:25 UTCApr 13, 21:10 UTC45m
2026-04-13 TWB162 SIN → ICN Apr 13, 18:15 UTCApr 13, 19:20 UTC1h 5m
2026-04-13 TWB161 - Apr 13, 08:55 UTCApr 13, 10:00 UTC1h 5m
2026-04-13 TWB161 - Apr 13, 07:10 UTCApr 13, 07:45 UTC35m
2026-04-12 TWB162 SIN → ICN Apr 12, 18:10 UTCApr 12, 20:15 UTC2h 5m

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 HL8561 page for operator, model, and routing details .

Mode-S 71C561 frequently asked

What is Mode-S code 71C561?
71C561 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8561.
Where is Mode-S 71C561 registered?
Mode-S code 71C561 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 71C561 broadcasting right now?
No active broadcast right now. Last signal was 19h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C561, octal 34342541, decimal 7,456,097.
What flights does 71C561 operate?
Mode-S 71C561 has broadcast 2 distinct callsigns, including TWB161, TWB162.