Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

71C531

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

Currently assigned to HL8531 · AIRBUS A-321neo

Hex
71C531
Octal
34342461
Decimal
7,456,049
Country
KR
Tail
HL8531
Type
A21N
No current signal · last broadcast 2h ago
Flights observed
167
Distinct callsigns
20
Country
KR
Last broadcast
2h ago

Last known position

Most recent position reported by Mode-S 71C531.

Country allocation

The ICAO 24-bit address 71C531 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 20 distinct

Callsign Airline Flights Last seen
KAL2174 Korean Air 7 2026-05-29
KAL2171 Korean Air 7 2026-05-29
KAL2173 Korean Air 6 2026-05-29
KAL2172 Korean Air 6 2026-05-29
KAL625 Korean Air 5 2026-05-18
KAL2180 Korean Air 5 2026-05-16
KAL2179 Korean Air 5 2026-05-16
KAL2147 Korean Air 5 2026-05-16
KAL742 Korean Air 4 2026-05-22
KAL626 Korean Air 4 2026-05-18
KAL2148 Korean Air 4 2026-05-16
KAL2016 Korean Air 4 2026-05-17
KAL2015 Korean Air 4 2026-05-17
KAL1410 Korean Air 4 2026-05-28
KAL1407 Korean Air 4 2026-05-26
KAL891 Korean Air 3 2026-05-22
KAL842 Korean Air 3 2026-05-30
KAL841 Korean Air 3 2026-05-29
KAL741 Korean Air 3 2026-05-22
KAL2132 Korean Air 3 2026-05-27

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 KAL842 TAO → ICN May 30, 02:40 UTCMay 30, 03:00 UTC20m
2026-05-29 KAL841 ICN → TAO May 29, 23:00 UTCMay 29, 23:35 UTC35m
2026-05-29 KAL2174 UKB → ICN May 29, 10:00 UTCMay 29, 11:30 UTC1h 30m
2026-05-29 KAL2173 ICN → UKB May 29, 07:10 UTCMay 29, 08:20 UTC1h 10m
2026-05-29 KAL2172 UKB → ICN May 29, 03:10 UTCMay 29, 04:40 UTC1h 30m
2026-05-29 KAL2171 ICN → UKB May 29, 00:30 UTCMay 29, 01:45 UTC1h 15m
2026-05-28 KAL1410 PUS → ICN May 28, 07:45 UTCMay 28, 08:25 UTC40m
2026-05-28 KAL2086 TPE → PUS May 28, 04:05 UTCMay 28, 04:30 UTC25m
2026-05-27 KAL2132 NRT → PUS May 27, 10:40 UTCMay 28, 02:05 UTC15h 25m
2026-05-27 KAL2131 PUS → NRT May 27, 07:30 UTCMay 27, 08:40 UTC1h 10m
2026-05-27 KAL2130 NRT → PUS May 27, 03:59 UTCMay 27, 05:09 UTC1h 10m
2026-05-27 KAL2129 PUS → NRT May 27, 00:49 UTCMay 27, 02:19 UTC1h 30m
2026-05-26 KAL1407 ICN → PUS May 26, 09:59 UTCMay 26, 10:39 UTC40m
2026-05-26 KAL2198 KIJ → ICN May 26, 05:34 UTCMay 26, 07:19 UTC1h 45m
2026-05-26 KAL2197 ICN → KIJ May 26, 02:19 UTCMay 26, 03:45 UTC1h 25m
2026-05-25 KAL145 ICN → CSX May 25, 13:50 UTCMay 25, 21:04 UTC7h 14m
2026-05-25 KAL2174 UKB → ICN May 25, 10:10 UTCMay 25, 11:35 UTC1h 25m
2026-05-25 KAL2173 ICN → UKB May 25, 07:10 UTCMay 25, 08:35 UTC1h 25m
2026-05-25 KAL2172 UKB → ICN May 25, 03:10 UTCMay 25, 04:35 UTC1h 25m
2026-05-24 KAL2174 UKB → ICN May 24, 09:55 UTCMay 24, 11:15 UTC1h 20m
2026-05-24 KAL2173 ICN → UKB May 24, 07:10 UTCMay 24, 08:25 UTC1h 15m
2026-05-24 KAL2172 UKB → ICN May 24, 03:15 UTCMay 24, 04:40 UTC1h 25m
2026-05-24 KAL2171 ICN → UKB May 24, 00:20 UTCMay 24, 01:35 UTC1h 15m
2026-05-23 KAL712 NRT → ICN May 23, 08:35 UTCMay 23, 10:45 UTC2h 10m
2026-05-23 KAL711 ICN → NRT May 23, 04:25 UTCMay 23, 06:15 UTC1h 50m
2026-05-23 KAL892 PVG → ICN May 23, 02:10 UTCMay 23, 02:45 UTC34m
2026-05-22 KAL891 ICN → PVG May 22, 10:15 UTCMay 22, 10:45 UTC30m
2026-05-22 KAL742 NGO → ICN May 22, 05:05 UTCMay 22, 06:45 UTC1h 40m
2026-05-22 KAL741 ICN → NGO May 22, 02:15 UTCMay 22, 03:35 UTC1h 20m
2026-05-21 KAL726 KIX → ICN May 21, 10:00 UTCMay 21, 11:35 UTC1h 35m
2026-05-21 KAL725 ICN → KIX May 21, 06:20 UTCMay 21, 07:55 UTC1h 35m
2026-05-21 KAL842 TAO → ICN May 21, 02:40 UTCMay 21, 03:10 UTC30m
2026-05-20 KAL841 ICN → TAO May 20, 23:15 UTCMay 20, 23:50 UTC35m
2026-05-20 KAL876 - May 20, 12:50 UTCMay 20, 13:10 UTC20m
2026-05-20 KAL875 PUS → PVG May 20, 09:50 UTCMay 20, 10:15 UTC25m
2026-05-20 KAL892 PVG → ICN May 20, 02:20 UTCMay 20, 02:55 UTC35m
2026-05-19 KAL891 ICN → PVG May 19, 11:05 UTCMay 19, 11:35 UTC30m
2026-05-18 KAL626 CGK → ICN May 18, 17:25 UTCMay 18, 21:05 UTC3h 39m
2026-05-18 KAL625 ICN → CGK May 18, 14:45 UTCMay 18, 15:20 UTC35m
2026-05-18 KAL625 ICN → CGK May 18, 11:40 UTCMay 18, 13:25 UTC1h 45m
2026-05-18 KAL708 - May 18, 07:35 UTCMay 18, 09:35 UTC2h 0m
2026-05-18 KAL707 ICN → NRT May 18, 04:05 UTCMay 18, 06:05 UTC2h 0m
2026-05-17 KAL2016 MFM → ICN May 17, 06:35 UTCMay 17, 09:50 UTC3h 15m
2026-05-17 KAL2015 ICN → MFM May 17, 01:50 UTCMay 17, 04:50 UTC3h 0m
2026-05-16 KAL2180 KOJ → ICN May 16, 10:31 UTCMay 16, 11:25 UTC55m
2026-05-16 KAL2179 ICN → KOJ May 16, 07:51 UTCMay 16, 08:41 UTC50m
2026-05-16 KAL2148 OKA → ICN May 16, 05:30 UTCMay 16, 06:16 UTC46m
2026-05-16 KAL2148 OKA → ICN May 16, 04:15 UTCMay 16, 04:30 UTC15m
2026-05-16 KAL2147 ICN → OKA May 16, 02:10 UTCMay 16, 02:35 UTC25m
2026-05-16 KAL2147 ICN → OKA May 16, 00:45 UTCMay 16, 01:15 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 HL8531 page for operator, model, and routing details .

Mode-S 71C531 frequently asked

What is Mode-S code 71C531?
71C531 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8531.
Where is Mode-S 71C531 registered?
Mode-S code 71C531 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 71C531 broadcasting right now?
No active broadcast right now. Last signal was 2h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C531, octal 34342461, decimal 7,456,049.
What flights does 71C531 operate?
Mode-S 71C531 has broadcast 20 distinct callsigns, including KAL2174, KAL2171, KAL2173, KAL2172, KAL625.