Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

71C591

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

Currently assigned to HL8591 · AIRBUS A-321neo

Hex
71C591
Octal
34342621
Decimal
7,456,145
Country
KR
Tail
HL8591
Type
A21N
No current signal · last broadcast 5h ago
Flights observed
316
Distinct callsigns
20
Country
KR
Last broadcast
5h ago

Last known position

Most recent position reported by Mode-S 71C591.

Country allocation

The ICAO 24-bit address 71C591 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
KAL852 - 13 2026-06-29
KAL2174 - 12 2026-07-05
KAL2171 - 12 2026-07-05
KAL2016 - 11 2026-07-13
KAL2173 - 10 2026-07-05
KAL2172 - 10 2026-07-05
KAL2066 - 10 2026-06-29
KAL851 - 8 2026-06-28
KAL2065 Korean Air 8 2026-06-14
KAL737 - 7 2026-07-09
KAL2015 - 7 2026-07-13
KAL770 - 6 2026-06-28
KAL769 - 6 2026-06-28
KAL738 - 6 2026-07-09
KAL625 - 6 2026-07-13
KAL2198 - 6 2026-07-07
KAL2005 - 6 2026-06-24
KAL792 - 5 2026-07-03
KAL791 - 5 2026-07-03
KAL626 - 5 2026-07-13

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 KAL689 - Jul 14, 11:00 UTCJul 14, 13:50 UTC2h 50m
2026-07-14 KAL142 - Jul 14, 07:10 UTCJul 14, 07:35 UTC25m
2026-07-14 KAL141 - Jul 14, 00:50 UTCJul 14, 06:20 UTC5h 30m
2026-07-13 KAL626 - Jul 13, 17:30 UTCJul 13, 21:00 UTC3h 30m
2026-07-13 KAL625 ICN → MNL Jul 13, 11:45 UTCJul 13, 15:10 UTC3h 25m
2026-07-13 KAL2016 - Jul 13, 06:25 UTCJul 13, 09:40 UTC3h 15m
2026-07-13 KAL2015 - Jul 13, 01:35 UTCJul 13, 04:35 UTC3h 0m
2026-07-12 KAL726 - Jul 12, 09:40 UTCJul 12, 10:55 UTC1h 15m
2026-07-12 KAL725 - Jul 12, 06:25 UTCJul 12, 07:40 UTC1h 15m
2026-07-12 KAL486 - Jul 12, 01:05 UTCJul 12, 01:25 UTC20m
2026-07-11 KAL485 - Jul 11, 12:35 UTCJul 11, 21:55 UTC9h 20m
2026-07-10 KAL626 - Jul 10, 19:20 UTCJul 10, 23:45 UTC4h 25m
2026-07-10 KAL625 - Jul 10, 12:45 UTCJul 10, 17:15 UTC4h 30m
2026-07-10 KAL2016 - Jul 10, 09:20 UTCJul 10, 10:00 UTC40m
2026-07-10 KAL2016 - Jul 10, 06:55 UTCJul 10, 07:05 UTC10m
2026-07-10 KAL2015 - Jul 10, 01:55 UTCJul 10, 05:00 UTC3h 5m
2026-07-09 KAL738 KIX → ICN Jul 9, 17:25 UTCJul 9, 18:50 UTC1h 25m
2026-07-09 KAL737 ICN → KIX Jul 9, 12:05 UTCJul 9, 13:40 UTC1h 35m
2026-07-09 KAL1410 PUS → ICN Jul 9, 07:45 UTCJul 9, 08:35 UTC50m
2026-07-09 KAL2086 - Jul 9, 05:35 UTCJul 9, 06:05 UTC30m
2026-07-09 KAL2086 - Jul 9, 04:10 UTCJul 9, 04:35 UTC25m
2026-07-09 KAL2085 - Jul 9, 00:25 UTCJul 9, 02:15 UTC1h 50m
2026-07-08 KAL1401 ICN → PUS Jul 8, 22:05 UTCJul 8, 22:45 UTC40m
2026-07-08 KAL772 - Jul 8, 12:10 UTCJul 8, 14:35 UTC2h 25m
2026-07-08 KAL771 - Jul 8, 08:20 UTCJul 8, 10:40 UTC2h 20m
2026-07-08 KAL2194 - Jul 8, 03:55 UTCJul 8, 06:05 UTC2h 10m
2026-07-08 KAL2193 - Jul 8, 00:20 UTCJul 8, 02:20 UTC2h 0m
2026-07-07 KAL2198 - Jul 7, 04:30 UTCJul 7, 06:05 UTC1h 35m
2026-07-07 KAL2197 - Jul 7, 01:15 UTCJul 7, 02:35 UTC1h 20m
2026-07-06 KAL726 KIX → ICN Jul 6, 09:35 UTCJul 6, 11:05 UTC1h 30m
2026-07-06 KAL725 ICN → KIX Jul 6, 06:30 UTCJul 6, 07:55 UTC1h 25m
2026-07-06 KAL2190 - Jul 6, 01:20 UTCJul 6, 02:55 UTC1h 35m
2026-07-05 KAL2189 - Jul 5, 22:40 UTCJul 6, 00:05 UTC1h 25m
2026-07-05 KAL2174 UKB → ICN Jul 5, 10:05 UTCJul 5, 11:35 UTC1h 30m
2026-07-05 KAL2173 ICN → UKB Jul 5, 07:10 UTCJul 5, 08:30 UTC1h 20m
2026-07-05 KAL2172 UKB → ICN Jul 5, 03:05 UTCJul 5, 04:35 UTC1h 30m
2026-07-05 KAL2171 ICN → UKB Jul 5, 00:25 UTCJul 5, 01:35 UTC1h 10m
2026-07-04 KAL864 - Jul 4, 19:20 UTCJul 4, 19:45 UTC25m
2026-07-04 KAL863 - Jul 4, 11:20 UTCJul 4, 11:35 UTC15m
2026-07-04 KAL2198 - Jul 4, 05:25 UTCJul 4, 05:50 UTC25m
2026-07-04 KAL2198 - Jul 4, 04:10 UTCJul 4, 04:55 UTC45m
2026-07-04 KAL2197 - Jul 4, 01:00 UTCJul 4, 02:25 UTC1h 25m
2026-07-03 KAL876 - Jul 3, 12:40 UTCJul 3, 13:05 UTC25m
2026-07-03 KAL875 - Jul 3, 09:50 UTCJul 3, 10:10 UTC20m
2026-07-03 KAL792 - Jul 3, 06:15 UTCJul 3, 07:15 UTC1h 0m
2026-07-03 KAL791 - Jul 3, 02:20 UTCJul 3, 03:05 UTC45m
2026-07-02 KAL2180 - Jul 2, 10:10 UTCJul 2, 11:05 UTC55m
2026-07-02 KAL2179 - Jul 2, 07:30 UTCJul 2, 08:25 UTC55m
2026-07-01 KAL127 ICN → ICN Jul 1, 23:25 UTCJul 2, 05:35 UTC6h 10m
2026-07-01 KAL457 ICN → ICN Jul 1, 03:05 UTCJul 1, 13:20 UTC10h 15m

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 HL8591 page for operator, model, and routing details .

Mode-S 71C591 frequently asked

What is Mode-S code 71C591?
71C591 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8591.
Where is Mode-S 71C591 registered?
Mode-S code 71C591 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 71C591 broadcasting right now?
No active broadcast right now. Last signal was 5h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C591, octal 34342621, decimal 7,456,145.
What flights does 71C591 operate?
Mode-S 71C591 has broadcast 20 distinct callsigns, including KAL852, KAL2174, KAL2171, KAL2016, KAL2173.