Apparatus

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sensors Mode-S transponder

71C546

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

Currently assigned to HL8546 · BOEING 737-800

Hex
71C546
Octal
34342506
Decimal
7,456,070
Country
KR
Tail
HL8546
Type
B738
No current signal · last broadcast Jul 26, 19:15 UTC
Flights observed
469
Distinct callsigns
20
Country
KR
Last broadcast
Jul 26, 19:15 UTC

Last known position

Most recent position reported by Mode-S 71C546.

Country allocation

The ICAO 24-bit address 71C546 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
ESR604 Eastar Jet 20 2026-07-22
ESR818 Eastar Jet 17 2026-07-24
ESR603 - 17 2026-07-16
ESR817 Eastar Jet 16 2026-07-24
ESR650 Eastar Jet 13 2026-07-23
ESR649 Eastar Jet 13 2026-07-23
ESR612 Eastar Jet 13 2026-07-22
ESR611 Eastar Jet 13 2026-07-22
ESR872 Eastar Jet 12 2026-07-25
ESR608 - 12 2026-06-22
ESR648 Eastar Jet 11 2026-07-25
ESR647 Eastar Jet 11 2026-07-25
ESR645 Eastar Jet 11 2026-07-21
ESR646 Eastar Jet 10 2026-07-21
ESR607 - 9 2026-06-22
ESR605 Eastar Jet 9 2026-07-25
ESR983 Eastar Jet 8 2026-04-28
ESR861 Eastar Jet 8 2026-07-26
ESR854 Eastar Jet 8 2026-07-24
ESR853 Eastar Jet 8 2026-07-24

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 ESR862 HKG → ICN Jul 26, 15:55 UTCJul 26, 19:10 UTC3h 15m
2026-07-26 ESR861 ICN → HKG Jul 26, 13:50 UTCJul 26, 14:05 UTC15m
2026-07-26 ESR861 ICN → HKG Jul 26, 10:50 UTCJul 26, 13:20 UTC2h 30m
2026-07-26 ESR820 YNT → ICN Jul 26, 08:40 UTCJul 26, 09:05 UTC25m
2026-07-26 ESR819 ICN → YNT Jul 26, 05:55 UTCJul 26, 06:25 UTC30m
2026-07-26 ESR606 NRT → ICN Jul 26, 02:20 UTCJul 26, 04:15 UTC1h 55m
2026-07-25 ESR605 ICN → NRT Jul 25, 22:40 UTCJul 26, 00:30 UTC1h 50m
2026-07-25 ESR872 PVG → ICN Jul 25, 13:50 UTCJul 25, 18:35 UTC4h 45m
2026-07-25 ESR648 FUK → ICN Jul 25, 06:30 UTCJul 25, 07:25 UTC55m
2026-07-25 ESR647 ICN → FUK Jul 25, 03:45 UTCJul 25, 04:40 UTC55m
2026-07-24 ESR562 CXR → ICN Jul 24, 13:25 UTCJul 25, 00:35 UTC11h 10m
2026-07-24 ESR854 CGO → ICN Jul 24, 11:30 UTCJul 24, 12:00 UTC30m
2026-07-24 ESR853 ICN → CGO Jul 24, 06:40 UTCJul 24, 10:40 UTC4h 0m
2026-07-24 ESR818 YNT → ICN Jul 24, 03:30 UTCJul 24, 03:50 UTC20m
2026-07-24 ESR817 ICN → YNT Jul 24, 00:30 UTCJul 24, 00:50 UTC20m
2026-07-23 ESR650 FUK → ICN Jul 23, 12:00 UTCJul 23, 13:05 UTC1h 5m
2026-07-23 ESR649 ICN → FUK Jul 23, 09:35 UTCJul 23, 10:15 UTC40m
2026-07-23 ESR648 FUK → ICN Jul 23, 06:35 UTCJul 23, 07:25 UTC50m
2026-07-23 ESR647 ICN → FUK Jul 23, 03:40 UTCJul 23, 04:40 UTC1h 0m
2026-07-22 ESR871 ICN → ICN Jul 22, 14:45 UTCJul 22, 19:15 UTC4h 30m
2026-07-22 ESR604 NRT → ICN Jul 22, 11:15 UTCJul 22, 13:05 UTC1h 50m
2026-07-22 ESR612 KIX → ICN Jul 22, 04:25 UTCJul 22, 05:25 UTC1h 0m
2026-07-22 ESR611 ICN → KIX Jul 22, 00:40 UTCJul 22, 02:00 UTC1h 20m
2026-07-21 ESR624 - Jul 21, 08:55 UTCJul 21, 11:20 UTC2h 25m
2026-07-21 ESR623 ICN → CTS Jul 21, 05:15 UTCJul 21, 07:30 UTC2h 15m
2026-07-21 ESR646 FUK → ICN Jul 21, 02:45 UTCJul 21, 03:45 UTC1h 0m
2026-07-21 ESR645 ICN → FUK Jul 21, 00:15 UTCJul 21, 01:05 UTC50m
2026-07-20 ESR593 ICN → ICN Jul 20, 12:40 UTCJul 20, 22:25 UTC9h 45m
2026-07-20 ESR614 KIX → ICN Jul 20, 09:30 UTCJul 20, 10:55 UTC1h 25m
2026-07-20 ESR613 ICN → KIX Jul 20, 06:55 UTCJul 20, 08:25 UTC1h 30m
2026-07-20 ESR882 TPE → ICN Jul 20, 03:05 UTCJul 20, 05:10 UTC2h 5m
2026-07-19 ESR881 ICN → TPE Jul 19, 23:10 UTCJul 20, 01:20 UTC2h 10m
2026-07-19 ESR872 PVG → ICN Jul 19, 13:35 UTCJul 19, 18:25 UTC4h 50m
2026-07-19 ESR8262 - Jul 19, 11:25 UTCJul 19, 11:50 UTC25m
2026-07-19 ESR8262 - Jul 19, 10:15 UTCJul 19, 10:45 UTC30m
2026-07-19 ESR8261 - Jul 19, 06:50 UTCJul 19, 08:35 UTC1h 45m
2026-07-19 ESR882 TPE → ICN Jul 19, 02:45 UTCJul 19, 04:50 UTC2h 5m
2026-07-19 ESR881 ICN → TPE Jul 19, 00:30 UTCJul 19, 01:05 UTC35m
2026-07-18 ESR881 ICN → TPE Jul 18, 23:00 UTCJul 18, 23:40 UTC40m
2026-07-18 ESR650 FUK → ICN Jul 18, 12:00 UTCJul 18, 13:00 UTC1h 0m
2026-07-18 ESR649 - Jul 18, 09:25 UTCJul 18, 10:05 UTC40m
2026-07-18 ESR602 NRT → ICN Jul 18, 02:45 UTCJul 18, 04:40 UTC1h 56m
2026-07-17 ESR601 ICN → NRT Jul 17, 23:20 UTCJul 18, 01:10 UTC1h 50m
2026-07-17 ESR872 ICN → ICN Jul 17, 14:15 UTCJul 17, 18:44 UTC4h 30m
2026-07-17 ESR820 - Jul 17, 09:10 UTCJul 17, 09:35 UTC25m
2026-07-17 ESR819 - Jul 17, 06:00 UTCJul 17, 06:25 UTC25m
2026-07-17 ESR606 NRT → ICN Jul 17, 02:25 UTCJul 17, 04:14 UTC1h 50m
2026-07-16 ESR605 ICN → NRT Jul 16, 22:35 UTCJul 17, 00:30 UTC1h 55m
2026-07-16 ESR872 ICN → ICN Jul 16, 13:45 UTCJul 16, 18:25 UTC4h 40m
2026-07-16 ESR604 NRT → ICN Jul 16, 09:50 UTCJul 16, 11:45 UTC1h 55m

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 HL8546 page for operator, model, and routing details .

Mode-S 71C546 frequently asked

What is Mode-S code 71C546?
71C546 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8546.
Where is Mode-S 71C546 registered?
Mode-S code 71C546 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 71C546 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 19:15 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C546, octal 34342506, decimal 7,456,070.
What flights does 71C546 operate?
Mode-S 71C546 has broadcast 20 distinct callsigns, including ESR604, ESR818, ESR603, ESR817, ESR650.