Apparatus

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sensors Mode-S transponder

71C537

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

Currently assigned to HL8537 · BOEING 787-10 Dreamliner

Hex
71C537
Octal
34342467
Decimal
7,456,055
Country
KR
Tail
HL8537
Type
B78X
No current signal · last broadcast Jul 26, 21:40 UTC
Flights observed
252
Distinct callsigns
20
Country
KR
Last broadcast
Jul 26, 21:40 UTC

Last known position

Most recent position reported by Mode-S 71C537.

Country allocation

The ICAO 24-bit address 71C537 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
KAL053 Korean Air 24 2026-07-23
KAL054 Korean Air 18 2026-07-23
KAL970 - 16 2026-07-18
KAL969 - 14 2026-07-17
KAL041 - 14 2026-07-11
KAL042 - 13 2026-07-11
KAL402 Korean Air 11 2026-07-22
KAL401 Korean Air 11 2026-07-22
KAL024 Korean Air 8 2026-07-26
KAL023 Korean Air 8 2026-07-26
KAL724 - 7 2026-07-09
KAL448 - 7 2026-07-14
KAL434 - 7 2026-07-12
KAL072 Korean Air 7 2026-05-13
KAL938 - 6 2026-07-11
KAL918 Korean Air 6 2026-07-26
KAL723 - 6 2026-07-09
KAL071 Korean Air 6 2026-05-13
KAL964 Korean Air 5 2026-05-30
KAL963 Korean Air 5 2026-05-30

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 KAL024 SFO → ICN Jul 26, 20:35 UTCJul 26, 21:40 UTC1h 5m
2026-07-26 KAL023 ICN → SFO Jul 26, 07:30 UTCJul 26, 17:55 UTC10h 25m
2026-07-26 KAL918 ZRH → ICN Jul 26, 04:25 UTCJul 26, 04:45 UTC20m
2026-07-25 KAL918 ZRH → ICN Jul 25, 18:00 UTCJul 26, 03:35 UTC9h 35m
2026-07-25 KAL917 ICN → ZRH Jul 25, 03:55 UTCJul 25, 15:05 UTC11h 10m
2026-07-25 KAL917 ICN → ZRH Jul 25, 02:45 UTCJul 25, 03:10 UTC25m
2026-07-23 KAL054 HNL → ICN Jul 23, 23:30 UTCJul 24, 08:35 UTC9h 5m
2026-07-23 KAL053 ICN → HNL Jul 23, 12:35 UTCJul 23, 14:25 UTC1h 50m
2026-07-22 KAL402 SYD → ICN Jul 22, 22:45 UTCJul 23, 08:45 UTC10h 0m
2026-07-22 KAL401 ICN → SYD Jul 22, 11:10 UTCJul 22, 20:35 UTC9h 25m
2026-07-21 KAL402 SYD → ICN Jul 21, 22:45 UTCJul 22, 00:45 UTC2h 0m
2026-07-21 KAL401 ICN → SYD Jul 21, 10:55 UTCJul 21, 20:45 UTC9h 50m
2026-07-20 KAL024 SFO → ICN Jul 20, 20:45 UTCJul 21, 08:30 UTC11h 44m
2026-07-20 KAL023 ICN → SFO Jul 20, 07:20 UTCJul 20, 17:55 UTC10h 35m
2026-07-18 KAL024 SFO → ICN Jul 18, 21:20 UTCJul 19, 08:25 UTC11h 5m
2026-07-18 KAL023 - Jul 18, 07:40 UTCJul 18, 18:30 UTC10h 50m
2026-07-18 KAL970 - Jul 18, 03:10 UTCJul 18, 03:30 UTC20m
2026-07-17 KAL970 - Jul 17, 17:30 UTCJul 18, 02:25 UTC8h 55m
2026-07-17 KAL969 ICN → PRG Jul 17, 03:55 UTCJul 17, 15:00 UTC11h 5m
2026-07-17 KAL969 - Jul 17, 02:45 UTCJul 17, 03:05 UTC20m
2026-07-16 KAL433 ICN → ICN Jul 16, 09:25 UTCJul 16, 23:59 UTC14h 35m
2026-07-16 KAL928 - Jul 16, 06:20 UTCJul 16, 06:50 UTC30m
2026-07-16 KAL928 - Jul 16, 05:15 UTCJul 16, 05:35 UTC20m
2026-07-15 KAL928 - Jul 15, 20:30 UTCJul 15, 22:00 UTC1h 30m
2026-07-15 KAL927 - Jul 15, 06:20 UTCJul 15, 17:45 UTC11h 25m
2026-07-15 KAL927 - Jul 15, 05:10 UTCJul 15, 05:25 UTC15m
2026-07-14 KAL448 - Jul 14, 19:35 UTCJul 14, 20:10 UTC35m
2026-07-14 KAL448 - Jul 14, 16:30 UTCJul 14, 16:40 UTC10m
2026-07-14 KAL447 - Jul 14, 10:30 UTCJul 14, 13:10 UTC2h 40m
2026-07-14 KAL970 - Jul 14, 04:10 UTCJul 14, 04:30 UTC20m
2026-07-13 KAL970 - Jul 13, 18:00 UTCJul 14, 03:15 UTC9h 15m
2026-07-13 KAL969 - Jul 13, 02:20 UTCJul 13, 14:45 UTC12h 25m
2026-07-12 KAL434 ICN → ICN Jul 12, 09:40 UTCJul 12, 23:55 UTC14h 15m
2026-07-11 KAL042 SEA → ICN Jul 11, 20:40 UTCJul 12, 07:10 UTC10h 30m
2026-07-11 KAL041 ICN → SEA Jul 11, 08:05 UTCJul 11, 17:45 UTC9h 40m
2026-07-11 KAL938 - Jul 11, 02:25 UTCJul 11, 02:50 UTC25m
2026-07-10 KAL938 - Jul 10, 16:50 UTCJul 11, 01:35 UTC8h 45m
2026-07-10 KAL937 - Jul 10, 03:20 UTCJul 10, 14:10 UTC10h 50m
2026-07-10 KAL937 - Jul 10, 02:00 UTCJul 10, 02:20 UTC20m
2026-07-09 KAL724 KIX → ICN Jul 9, 04:30 UTCJul 9, 05:55 UTC1h 25m
2026-07-09 KAL723 - Jul 9, 01:05 UTCJul 9, 02:35 UTC1h 30m
2026-07-08 KAL448 - Jul 8, 19:40 UTCJul 8, 20:20 UTC40m
2026-07-08 KAL448 - Jul 8, 16:30 UTCJul 8, 16:45 UTC15m
2026-07-08 KAL447 - Jul 8, 10:45 UTCJul 8, 14:30 UTC3h 45m
2026-07-07 KAL054 - Jul 7, 23:30 UTCJul 8, 08:40 UTC9h 10m
2026-07-07 KAL053 - Jul 7, 12:35 UTCJul 7, 14:25 UTC1h 50m
2026-07-06 KAL448 - Jul 6, 19:20 UTCJul 6, 20:10 UTC50m
2026-07-06 KAL448 - Jul 6, 16:30 UTCJul 6, 16:40 UTC10m
2026-07-06 KAL447 - Jul 6, 10:15 UTCJul 6, 10:55 UTC40m
2026-07-05 KAL042 SEA → ICN Jul 5, 20:50 UTCJul 6, 08:00 UTC11h 10m

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 HL8537 page for operator, model, and routing details .

Mode-S 71C537 frequently asked

What is Mode-S code 71C537?
71C537 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8537.
Where is Mode-S 71C537 registered?
Mode-S code 71C537 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 71C537 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 21:40 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C537, octal 34342467, decimal 7,456,055.
What flights does 71C537 operate?
Mode-S 71C537 has broadcast 20 distinct callsigns, including KAL053, KAL054, KAL970, KAL969, KAL041.