Apparatus

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sensors Mode-S transponder

71C542

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

Currently assigned to HL8542 · BOEING 737 MAX 8

Hex
71C542
Octal
34342502
Decimal
7,456,066
Country
KR
Tail
HL8542
Type
B38M
Transponder active on ground
Flights observed
542
Distinct callsigns
20
Country
KR
Last broadcast
Jul 26, 22:30 UTC

Last known position

Most recent position reported by Mode-S 71C542.

Country allocation

The ICAO 24-bit address 71C542 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
ESR952 - 11 2026-06-27
ESR951 - 10 2026-06-27
ESR284 Eastar Jet 10 2026-07-24
ESR283 Eastar Jet 10 2026-07-24
ESR219 Eastar Jet 10 2026-07-24
ESR988 - 9 2026-06-26
ESR983 - 9 2026-06-20
ESR230 Eastar Jet 9 2026-07-24
ESR212 Eastar Jet 9 2026-07-24
ESR211 Eastar Jet 9 2026-07-24
ESR206 Eastar Jet 9 2026-07-24
ESR916 - 8 2026-06-26
ESR915 - 8 2026-06-26
ESR913 - 8 2026-06-23
ESR233 - 8 2026-07-20
ESR224 Eastar Jet 8 2026-07-20
ESR987 - 7 2026-06-26
ESR984 - 7 2026-06-20
ESR918 - 7 2026-06-25
ESR914 - 7 2026-06-24

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ESR205 GMP → CJU Jul 26, 22:05 UTCJul 26, 22:30 UTC25m
2026-07-26 ESR228 CJU → GMP Jul 26, 11:15 UTCJul 26, 11:50 UTC35m
2026-07-26 ESR227 GMP → CJU Jul 26, 09:10 UTCJul 26, 09:40 UTC30m
2026-07-26 ESR220 CJU → GMP Jul 26, 07:20 UTCJul 26, 08:05 UTC45m
2026-07-26 ESR217 GMP → CJU Jul 26, 05:15 UTCJul 26, 05:50 UTC35m
2026-07-26 ESR210 CJU → GMP Jul 26, 03:25 UTCJul 26, 04:05 UTC40m
2026-07-26 ESR209 GMP → CJU Jul 26, 01:15 UTCJul 26, 01:45 UTC30m
2026-07-25 ESR202 CJU → GMP Jul 25, 23:25 UTCJul 26, 00:10 UTC45m
2026-07-25 ESR201 GMP → CJU Jul 25, 21:20 UTCJul 25, 21:50 UTC30m
2026-07-25 ESR228 CJU → GMP Jul 25, 11:25 UTCJul 25, 12:05 UTC40m
2026-07-25 ESR227 GMP → CJU Jul 25, 09:15 UTCJul 25, 09:50 UTC35m
2026-07-25 ESR220 CJU → GMP Jul 25, 07:30 UTCJul 25, 08:10 UTC40m
2026-07-25 ESR217 GMP → CJU Jul 25, 05:00 UTCJul 25, 05:35 UTC35m
2026-07-25 ESR210 CJU → GMP Jul 25, 03:15 UTCJul 25, 03:55 UTC40m
2026-07-25 ESR209 GMP → CJU Jul 25, 01:15 UTCJul 25, 01:45 UTC30m
2026-07-24 ESR202 CJU → GMP Jul 24, 23:25 UTCJul 25, 00:05 UTC40m
2026-07-24 ESR201 GMP → CJU Jul 24, 21:25 UTCJul 24, 22:00 UTC35m
2026-07-24 ESR230 CJU → GMP Jul 24, 12:00 UTCJul 24, 12:40 UTC40m
2026-07-24 ESR283 GMP → CJU Jul 24, 10:00 UTCJul 24, 10:40 UTC40m
2026-07-24 ESR284 CJU → GMP Jul 24, 08:20 UTCJul 24, 09:00 UTC40m
2026-07-24 ESR219 GMP → CJU Jul 24, 06:05 UTCJul 24, 06:40 UTC35m
2026-07-24 ESR212 CJU → GMP Jul 24, 04:25 UTCJul 24, 05:05 UTC40m
2026-07-24 ESR211 GMP → CJU Jul 24, 02:15 UTCJul 24, 02:50 UTC35m
2026-07-24 ESR206 CJU → GMP Jul 24, 00:20 UTCJul 24, 01:00 UTC40m
2026-07-23 ESR277 - Jul 23, 10:45 UTCJul 23, 11:20 UTC35m
2026-07-23 ESR222 CJU → GMP Jul 23, 08:50 UTCJul 23, 09:35 UTC45m
2026-07-23 ESR221 GMP → CJU Jul 23, 06:30 UTCJul 23, 07:10 UTC40m
2026-07-23 ESR214 CJU → GMP Jul 23, 04:35 UTCJul 23, 05:15 UTC40m
2026-07-23 ESR281 GMP → CJU Jul 23, 02:30 UTCJul 23, 03:05 UTC35m
2026-07-23 ESR282 CJU → GMP Jul 23, 00:50 UTCJul 23, 01:30 UTC40m
2026-07-22 ESR205 GMP → CJU Jul 22, 22:05 UTCJul 22, 22:40 UTC35m
2026-07-22 ESR228 CJU → GMP Jul 22, 11:20 UTCJul 22, 12:00 UTC40m
2026-07-22 ESR217 GMP → CJU Jul 22, 05:05 UTCJul 22, 05:25 UTC20m
2026-07-22 ESR210 CJU → GMP Jul 22, 03:15 UTCJul 22, 03:55 UTC40m
2026-07-22 ESR209 GMP → CJU Jul 22, 01:10 UTCJul 22, 01:45 UTC35m
2026-07-21 ESR202 CJU → GMP Jul 21, 23:25 UTCJul 22, 00:05 UTC40m
2026-07-21 ESR201 GMP → CJU Jul 21, 21:25 UTCJul 21, 22:00 UTC35m
2026-07-21 ESR278 - Jul 21, 13:15 UTCJul 21, 13:55 UTC40m
2026-07-21 ESR277 - Jul 21, 11:00 UTCJul 21, 11:35 UTC35m
2026-07-21 ESR222 CJU → GMP Jul 21, 09:10 UTCJul 21, 09:50 UTC40m
2026-07-21 ESR221 GMP → CJU Jul 21, 06:50 UTCJul 21, 07:25 UTC35m
2026-07-21 ESR214 CJU → GMP Jul 21, 04:55 UTCJul 21, 05:40 UTC45m
2026-07-21 ESR281 GMP → CJU Jul 21, 02:45 UTCJul 21, 03:20 UTC35m
2026-07-21 ESR282 CJU → GMP Jul 21, 01:00 UTCJul 21, 01:35 UTC35m
2026-07-20 ESR711 CJJ → CJU Jul 20, 22:50 UTCJul 20, 23:20 UTC30m
2026-07-20 ESR782 TPE → CJJ Jul 20, 19:05 UTCJul 20, 21:05 UTC2h 0m
2026-07-20 ESR781 CJJ → TPE Jul 20, 15:45 UTCJul 20, 17:40 UTC1h 55m
2026-07-20 ESR716 - Jul 20, 13:55 UTCJul 20, 14:25 UTC30m
2026-07-20 ESR233 - Jul 20, 11:55 UTCJul 20, 12:25 UTC30m
2026-07-20 ESR224 CJU → GMP Jul 20, 10:10 UTCJul 20, 10:50 UTC40m

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 HL8542 page for operator, model, and routing details .

Mode-S 71C542 frequently asked

What is Mode-S code 71C542?
71C542 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8542.
Where is Mode-S 71C542 registered?
Mode-S code 71C542 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 71C542 broadcasting right now?
Mode-S 71C542 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 71C542, octal 34342502, decimal 7,456,066.
What flights does 71C542 operate?
Mode-S 71C542 has broadcast 20 distinct callsigns, including ESR952, ESR951, ESR284, ESR283, ESR219.