Apparatus

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sensors Mode-S transponder

71C541

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

Currently assigned to HL8541 · BOEING 737 MAX 8

Hex
71C541
Octal
34342501
Decimal
7,456,065
Country
KR
Tail
HL8541
Type
B38M
No current signal · last broadcast 32m ago
Flights observed
448
Distinct callsigns
20
Country
KR
Last broadcast
32m ago

Last known position

Most recent position reported by Mode-S 71C541.

Country allocation

The ICAO 24-bit address 71C541 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
ESR632 Eastar Jet 19 2026-05-14
ESR631 Eastar Jet 18 2026-05-14
ESR951 - 16 2026-07-10
ESR861 Eastar Jet 15 2026-05-14
ESR952 - 14 2026-07-10
ESR913 - 12 2026-07-10
ESR536 Eastar Jet 12 2026-05-16
ESR918 - 11 2026-07-12
ESR917 - 10 2026-07-12
ESR862 Eastar Jet 10 2026-05-14
ESR915 - 9 2026-07-12
ESR914 - 9 2026-07-10
ESR271 - 9 2026-07-08
ESR219 - 9 2026-07-13
ESR212 - 9 2026-07-13
ESR211 - 9 2026-07-13
ESR284 - 8 2026-07-13
ESR206 - 8 2026-07-13
ESR968 - 7 2026-07-09
ESR967 - 7 2026-07-09

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-14 ESR208 - Jul 14, 01:20 UTCJul 14, 02:05 UTC45m
2026-07-13 ESR207 - Jul 13, 22:55 UTCJul 13, 23:30 UTC35m
2026-07-13 ESR262F ICN → GMP Jul 13, 21:50 UTCJul 13, 22:00 UTC10m
2026-07-13 ESR152 - Jul 13, 13:50 UTCJul 13, 14:30 UTC40m
2026-07-13 ESR231 - Jul 13, 12:05 UTCJul 13, 12:35 UTC30m
2026-07-13 ESR284 - Jul 13, 10:25 UTCJul 13, 11:05 UTC40m
2026-07-13 ESR219 - Jul 13, 06:40 UTCJul 13, 07:15 UTC35m
2026-07-13 ESR212 - Jul 13, 04:25 UTCJul 13, 05:10 UTC45m
2026-07-13 ESR211 - Jul 13, 02:30 UTCJul 13, 03:01 UTC30m
2026-07-13 ESR206 - Jul 13, 00:45 UTCJul 13, 01:25 UTC40m
2026-07-12 ESR901 - Jul 12, 22:40 UTCJul 12, 23:00 UTC20m
2026-07-12 ESR918 - Jul 12, 20:40 UTCJul 12, 21:20 UTC40m
2026-07-12 ESR918 - Jul 12, 16:25 UTCJul 12, 17:40 UTC1h 15m
2026-07-12 ESR917 - Jul 12, 13:40 UTCJul 12, 14:55 UTC1h 15m
2026-07-12 ESR917 - Jul 12, 10:15 UTCJul 12, 10:30 UTC15m
2026-07-12 ESR916 KIX → PUS Jul 12, 07:15 UTCJul 12, 08:15 UTC1h 0m
2026-07-12 ESR915 PUS → KIX Jul 12, 04:40 UTCJul 12, 05:40 UTC1h 0m
2026-07-12 ESR942 - Jul 12, 02:20 UTCJul 12, 02:50 UTC30m
2026-07-12 ESR941 - Jul 12, 00:30 UTCJul 12, 00:45 UTC15m
2026-07-11 ESR982 - Jul 11, 12:35 UTCJul 11, 23:10 UTC10h 35m
2026-07-11 ESR981 - Jul 11, 11:30 UTCJul 11, 11:45 UTC15m
2026-07-11 ESR916 KIX → PUS Jul 11, 07:20 UTCJul 11, 08:15 UTC55m
2026-07-11 ESR915 PUS → KIX Jul 11, 04:30 UTCJul 11, 05:35 UTC1h 5m
2026-07-11 ESR942 - Jul 11, 02:05 UTCJul 11, 02:35 UTC30m
2026-07-11 ESR941 - Jul 11, 00:00 UTCJul 11, 00:20 UTC20m
2026-07-10 ESR952 - Jul 10, 09:50 UTCJul 10, 12:00 UTC2h 10m
2026-07-10 ESR951 - Jul 10, 06:20 UTCJul 10, 08:30 UTC2h 10m
2026-07-10 ESR914 KIX → PUS Jul 10, 03:35 UTCJul 10, 04:40 UTC1h 5m
2026-07-10 ESR913 PUS → KIX Jul 10, 01:10 UTCJul 10, 02:20 UTC1h 10m
2026-07-09 ESR918 - Jul 9, 20:40 UTCJul 9, 21:20 UTC40m
2026-07-09 ESR918 - Jul 9, 16:20 UTCJul 9, 16:30 UTC10m
2026-07-09 ESR917 - Jul 9, 10:10 UTCJul 9, 15:00 UTC4h 50m
2026-07-09 ESR968 - Jul 9, 06:00 UTCJul 9, 07:00 UTC1h 0m
2026-07-09 ESR967 - Jul 9, 03:35 UTCJul 9, 04:15 UTC40m
2026-07-09 ESR902 - Jul 9, 01:30 UTCJul 9, 01:45 UTC15m
2026-07-08 ESR271 - Jul 8, 23:00 UTCJul 8, 23:40 UTC40m
2026-07-08 ESR230 - Jul 8, 12:10 UTCJul 8, 12:50 UTC40m
2026-07-08 ESR283 - Jul 8, 09:55 UTCJul 8, 10:35 UTC40m
2026-07-08 ESR284 - Jul 8, 08:10 UTCJul 8, 08:50 UTC40m
2026-07-08 ESR219 - Jul 8, 06:10 UTCJul 8, 06:45 UTC35m
2026-07-08 ESR212 - Jul 8, 04:25 UTCJul 8, 05:10 UTC45m
2026-07-08 ESR211 - Jul 8, 02:15 UTCJul 8, 02:55 UTC40m
2026-07-08 ESR206 - Jul 8, 00:15 UTCJul 8, 00:55 UTC40m
2026-07-07 ESR901 - Jul 7, 22:15 UTCJul 7, 22:30 UTC15m
2026-07-07 ESR916 - Jul 7, 07:15 UTCJul 7, 08:15 UTC1h 0m
2026-07-07 ESR915 PUS → KIX Jul 7, 04:30 UTCJul 7, 05:30 UTC1h 0m
2026-07-07 ESR942 - Jul 7, 02:10 UTCJul 7, 02:40 UTC30m
2026-07-07 ESR941 - Jul 7, 00:25 UTCJul 7, 00:50 UTC25m
2026-07-06 ESR984 - Jul 6, 20:30 UTCJul 6, 21:10 UTC40m
2026-07-06 ESR984 - Jul 6, 19:05 UTCJul 6, 19:25 UTC20m

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 HL8541 page for operator, model, and routing details .

Mode-S 71C541 frequently asked

What is Mode-S code 71C541?
71C541 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8541.
Where is Mode-S 71C541 registered?
Mode-S code 71C541 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 71C541 broadcasting right now?
No active broadcast right now. Last signal was 32m ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C541, octal 34342501, decimal 7,456,065.
What flights does 71C541 operate?
Mode-S 71C541 has broadcast 20 distinct callsigns, including ESR632, ESR631, ESR951, ESR861, ESR952.