sensors Mode-S transponder

71F2D8

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

Hex
71F2D8
Octal
34371330
Decimal
7,467,736
Country
KR
No current signal · last broadcast Apr 23, 01:25 UTC
Flights observed
4
Distinct callsigns
3
Country
KR
Last broadcast
Apr 23, 01:25 UTC

Last known position

Most recent position reported by Mode-S 71F2D8.

Country allocation

The ICAO 24-bit address 71F2D8 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 3 distinct

Callsign Airline Flights Last seen
CU51 - 2 2026-04-21
UN34 - 1 2026-04-22
CU23 - 1 2026-04-20

Recent flights last 4

DateFlightRouteTakeoffLandingDuration
2026-04-22 UN34 - Apr 22, 02:05 UTCApr 23, 01:25 UTC23h 20m
2026-04-21 CU51 - Apr 21, 10:40 UTCApr 21, 11:25 UTC45m
2026-04-21 CU51 - Apr 21, 09:50 UTCApr 21, 10:10 UTC20m
2026-04-20 CU23 - Apr 20, 01:05 UTCApr 20, 02:05 UTC1h 0m

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.

Mode-S 71F2D8 frequently asked

What is Mode-S code 71F2D8?
71F2D8 is an ICAO 24-bit transponder address. Allocated to Korea, South.
Where is Mode-S 71F2D8 registered?
Mode-S code 71F2D8 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 71F2D8 broadcasting right now?
No active broadcast right now. Last signal was Apr 23, 01:25 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71F2D8, octal 34371330, decimal 7,467,736.
What flights does 71F2D8 operate?
Mode-S 71F2D8 has broadcast 3 distinct callsigns, including CU51, UN34, CU23.