Apparatus

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sensors Mode-S transponder

71C543

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

Currently assigned to HL8543 · BOEING 737 MAX 8

Hex
71C543
Octal
34342503
Decimal
7,456,067
Country
KR
Tail
HL8543
Type
B38M
Transponder active on ground
Flights observed
407
Distinct callsigns
20
Country
KR
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S 71C543.

Country allocation

The ICAO 24-bit address 71C543 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
ESR861 - 22 2026-07-06
ESR613 - 21 2026-07-18
ESR614 - 20 2026-07-18
ESR862 - 15 2026-07-06
ESR601 - 15 2026-07-04
ESR612 - 14 2026-07-11
ESR602 - 14 2026-07-05
ESR648 - 13 2026-07-16
ESR631 - 13 2026-07-14
ESR611 - 13 2026-07-11
ESR647 - 12 2026-07-16
ESR646 - 12 2026-07-17
ESR605 - 12 2026-07-17
ESR645 Eastar Jet 11 2026-07-16
ESR632 - 11 2026-07-14
ESR607 - 11 2026-06-27
ESR606 - 11 2026-07-18
ESR608 - 10 2026-06-27
ESR604 - 10 2026-07-01
ESR603 - 9 2026-07-01

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-18 ESR614 KIX → ICN Jul 18, 09:20 UTCJul 18, 10:40 UTC1h 20m
2026-07-18 ESR613 ICN → KIX Jul 18, 06:45 UTCJul 18, 08:15 UTC1h 30m
2026-07-18 ESR606 NRT → ICN Jul 18, 02:19 UTCJul 18, 04:10 UTC1h 51m
2026-07-17 ESR605 ICN → NRT Jul 17, 22:40 UTCJul 18, 00:35 UTC1h 55m
2026-07-17 ESR624 - Jul 17, 09:10 UTCJul 17, 11:25 UTC2h 15m
2026-07-17 ESR623 - Jul 17, 05:10 UTCJul 17, 07:30 UTC2h 20m
2026-07-17 ESR646 - Jul 17, 02:39 UTCJul 17, 03:34 UTC55m
2026-07-16 ESR645 ICN → FUK Jul 16, 23:55 UTCJul 17, 00:40 UTC45m
2026-07-16 ESR518 - Jul 16, 16:55 UTCJul 16, 21:40 UTC4h 45m
2026-07-16 ESR517 - Jul 16, 09:45 UTCJul 16, 14:29 UTC4h 45m
2026-07-16 ESR648 - Jul 16, 06:20 UTCJul 16, 07:20 UTC1h 0m
2026-07-16 ESR647 - Jul 16, 03:40 UTCJul 16, 04:30 UTC50m
2026-07-15 ESR561 ICN → ICN Jul 15, 12:35 UTCJul 15, 23:05 UTC10h 30m
2026-07-15 ESR820 - Jul 15, 08:50 UTCJul 15, 09:15 UTC25m
2026-07-15 ESR819 - Jul 15, 06:00 UTCJul 15, 06:15 UTC15m
2026-07-15 ESR606 NRT → ICN Jul 15, 02:00 UTCJul 15, 03:50 UTC1h 50m
2026-07-14 ESR605 ICN → NRT Jul 14, 22:40 UTCJul 15, 00:35 UTC1h 54m
2026-07-14 ESR632 - Jul 14, 06:25 UTCJul 14, 08:20 UTC1h 55m
2026-07-14 ESR631 - Jul 14, 04:15 UTCJul 14, 04:45 UTC30m
2026-07-14 ESR631 - Jul 14, 02:50 UTCJul 14, 03:25 UTC35m
2026-07-13 ESR632 - Jul 13, 06:40 UTCJul 13, 08:25 UTC1h 45m
2026-07-13 ESR631 - Jul 13, 04:05 UTCJul 13, 04:30 UTC25m
2026-07-13 ESR631 - Jul 13, 02:40 UTCJul 13, 03:15 UTC35m
2026-07-12 ESR536 ICN → ICN Jul 12, 11:45 UTCJul 12, 23:50 UTC12h 5m
2026-07-12 ESR648 - Jul 12, 06:10 UTCJul 12, 07:10 UTC1h 0m
2026-07-12 ESR647 - Jul 12, 03:50 UTCJul 12, 04:30 UTC40m
2026-07-11 ESR562 - Jul 11, 17:50 UTCJul 12, 01:30 UTC7h 40m
2026-07-11 ESR561 - Jul 11, 14:10 UTCJul 11, 14:25 UTC15m
2026-07-11 ESR614 KIX → ICN Jul 11, 09:20 UTCJul 11, 10:40 UTC1h 20m
2026-07-11 ESR613 - Jul 11, 06:35 UTCJul 11, 08:10 UTC1h 35m
2026-07-11 ESR612 KIX → ICN Jul 11, 03:20 UTCJul 11, 04:45 UTC1h 25m
2026-07-11 ESR611 ICN → KIX Jul 11, 00:25 UTCJul 11, 01:55 UTC1h 30m
2026-07-10 ESR650 - Jul 10, 11:55 UTCJul 10, 12:55 UTC1h 0m
2026-07-10 ESR649 - Jul 10, 09:35 UTCJul 10, 10:15 UTC40m
2026-07-10 ESR648 - Jul 10, 06:25 UTCJul 10, 07:25 UTC1h 0m
2026-07-10 ESR647 - Jul 10, 03:40 UTCJul 10, 04:35 UTC55m
2026-07-09 ESR535 ICN → ICN Jul 9, 11:50 UTCJul 9, 23:50 UTC12h 0m
2026-07-09 ESR632 - Jul 9, 07:20 UTCJul 9, 08:05 UTC45m
2026-07-09 ESR632 - Jul 9, 06:15 UTCJul 9, 06:30 UTC15m
2026-07-09 ESR631 - Jul 9, 02:55 UTCJul 9, 04:40 UTC1h 45m
2026-07-08 ESR518 - Jul 8, 16:55 UTCJul 8, 21:45 UTC4h 50m
2026-07-08 ESR517 - Jul 8, 09:45 UTCJul 8, 14:35 UTC4h 50m
2026-07-08 ESR882 - Jul 8, 02:50 UTCJul 8, 05:05 UTC2h 15m
2026-07-07 ESR881 ICN → TPE Jul 7, 23:00 UTCJul 8, 01:05 UTC2h 5m
2026-07-07 ESR632 - Jul 7, 07:25 UTCJul 7, 08:10 UTC45m
2026-07-07 ESR632 - Jul 7, 06:20 UTCJul 7, 06:30 UTC10m
2026-07-07 ESR631 - Jul 7, 02:50 UTCJul 7, 04:35 UTC1h 45m
2026-07-06 ESR862 HKG → ICN Jul 6, 16:20 UTCJul 6, 19:40 UTC3h 20m
2026-07-06 ESR861 - Jul 6, 11:30 UTCJul 6, 14:45 UTC3h 15m
2026-07-06 ESR626 - Jul 6, 04:35 UTCJul 6, 07:20 UTC2h 45m

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 HL8543 page for operator, model, and routing details .

Mode-S 71C543 frequently asked

What is Mode-S code 71C543?
71C543 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8543.
Where is Mode-S 71C543 registered?
Mode-S code 71C543 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 71C543 broadcasting right now?
Mode-S 71C543 is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C543, octal 34342503, decimal 7,456,067.
What flights does 71C543 operate?
Mode-S 71C543 has broadcast 20 distinct callsigns, including ESR861, ESR613, ESR614, ESR862, ESR601.