Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

71C504

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

Currently assigned to HL8504 · AIRBUS A-321neo

Hex
71C504
Octal
34342404
Decimal
7,456,004
Country
KR
Tail
HL8504
Type
A21N
No current signal · last broadcast 16h ago
Flights observed
199
Distinct callsigns
12
Country
KR
Last broadcast
16h ago

Last known position

Most recent position reported by Mode-S 71C504.

Country allocation

The ICAO 24-bit address 71C504 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 12 distinct

Callsign Airline Flights Last seen
ABL173 Air Busan 24 2026-05-29
ABL157 Air Busan 24 2026-05-28
ABL156 Air Busan 24 2026-05-28
ABL174 Air Busan 23 2026-05-29
ABL158 Air Busan 23 2026-05-28
ABL155 Air Busan 22 2026-05-29
ABL787 Air Busan 21 2026-05-28
ABL788 Air Busan 14 2026-05-25
ABL7485 Air Busan 10 2026-05-27
ABL7475 Air Busan 10 2026-05-27
ABL3945 Air Busan 2 2026-04-26
ABL3935 Air Busan 2 2026-04-26

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-29 ABL173 KIX → ICN May 29, 07:20 UTCMay 29, 08:45 UTC1h 25m
2026-05-29 ABL174 ICN → KIX May 29, 03:55 UTCMay 29, 05:10 UTC1h 15m
2026-05-29 ABL155 FUK → ICN May 29, 01:50 UTCMay 29, 02:30 UTC40m
2026-05-28 ABL156 ICN → FUK May 28, 22:45 UTCMay 28, 23:15 UTC30m
2026-05-28 ABL787 ICN → CXR May 28, 08:35 UTCMay 28, 19:30 UTC10h 55m
2026-05-28 ABL157 FUK → ICN May 28, 05:40 UTCMay 28, 06:20 UTC40m
2026-05-28 ABL158 ICN → FUK May 28, 02:15 UTCMay 28, 03:30 UTC1h 15m
2026-05-27 ABL7485 CNX → ICN May 27, 18:05 UTCMay 27, 22:55 UTC4h 50m
2026-05-27 ABL7475 ICN → CNX May 27, 11:20 UTCMay 27, 16:10 UTC4h 50m
2026-05-27 ABL173 KIX → ICN May 27, 07:25 UTCMay 27, 08:50 UTC1h 25m
2026-05-27 ABL174 ICN → KIX May 27, 03:59 UTCMay 27, 05:19 UTC1h 20m
2026-05-27 ABL155 FUK → ICN May 27, 01:24 UTCMay 27, 02:29 UTC1h 5m
2026-05-26 ABL156 ICN → FUK May 26, 22:39 UTCMay 26, 22:59 UTC20m
2026-05-26 ABL173 KIX → ICN May 26, 07:34 UTCMay 26, 08:54 UTC1h 20m
2026-05-26 ABL174 ICN → KIX May 26, 03:55 UTCMay 26, 05:25 UTC1h 30m
2026-05-26 ABL155 FUK → ICN May 26, 01:24 UTCMay 26, 02:19 UTC55m
2026-05-25 ABL156 ICN → FUK May 25, 22:49 UTCMay 25, 23:19 UTC30m
2026-05-25 ABL788 CXR → ICN May 25, 08:30 UTCMay 25, 19:30 UTC10h 59m
2026-05-25 ABL787 ICN → CXR May 25, 08:15 UTCMay 25, 08:25 UTC10m
2026-05-25 ABL157 FUK → ICN May 25, 05:35 UTCMay 25, 06:15 UTC40m
2026-05-25 ABL158 ICN → FUK May 25, 02:20 UTCMay 25, 02:50 UTC30m
2026-05-24 ABL7485 CNX → ICN May 24, 23:00 UTCMay 24, 23:10 UTC10m
2026-05-24 ABL7485 CNX → ICN May 24, 18:15 UTCMay 24, 18:40 UTC25m
2026-05-24 ABL7475 ICN → CNX May 24, 11:10 UTCMay 24, 16:20 UTC5h 10m
2026-05-24 ABL173 KIX → ICN May 24, 07:20 UTCMay 24, 08:45 UTC1h 25m
2026-05-24 ABL174 ICN → KIX May 24, 04:05 UTCMay 24, 05:20 UTC1h 15m
2026-05-24 ABL155 FUK → ICN May 24, 01:20 UTCMay 24, 02:20 UTC1h 0m
2026-05-23 ABL156 ICN → FUK May 23, 22:30 UTCMay 23, 23:00 UTC30m
2026-05-23 ABL787 ICN → CXR May 23, 08:30 UTCMay 23, 19:35 UTC11h 5m
2026-05-23 ABL157 FUK → ICN May 23, 02:20 UTCMay 23, 06:15 UTC3h 54m
2026-05-22 ABL788 CXR → ICN May 22, 08:45 UTCMay 22, 19:25 UTC10h 40m
2026-05-22 ABL157 FUK → ICN May 22, 05:30 UTCMay 22, 06:10 UTC40m
2026-05-22 ABL158 ICN → FUK May 22, 02:25 UTCMay 22, 02:50 UTC25m
2026-05-21 ABL7485 CNX → ICN May 21, 17:55 UTCMay 21, 22:40 UTC4h 45m
2026-05-21 ABL7475 ICN → CNX May 21, 11:20 UTCMay 21, 16:30 UTC5h 10m
2026-05-21 ABL173 KIX → ICN May 21, 07:20 UTCMay 21, 08:45 UTC1h 25m
2026-05-21 ABL174 ICN → KIX May 21, 03:50 UTCMay 21, 05:15 UTC1h 25m
2026-05-21 ABL155 FUK → ICN May 21, 01:20 UTCMay 21, 02:30 UTC1h 10m
2026-05-20 ABL156 ICN → FUK May 20, 22:45 UTCMay 20, 23:10 UTC25m
2026-05-20 ABL788 CXR → ICN May 20, 08:40 UTCMay 20, 19:25 UTC10h 45m
2026-05-20 ABL157 FUK → ICN May 20, 05:15 UTCMay 20, 06:20 UTC1h 5m
2026-05-20 ABL158 ICN → FUK May 20, 02:25 UTCMay 20, 02:50 UTC25m
2026-05-19 ABL173 KIX → ICN May 19, 07:20 UTCMay 19, 08:35 UTC1h 15m
2026-05-19 ABL174 ICN → KIX May 19, 04:05 UTCMay 19, 05:35 UTC1h 30m
2026-05-19 ABL155 FUK → ICN May 19, 01:25 UTCMay 19, 02:25 UTC1h 0m
2026-05-18 ABL156 ICN → FUK May 18, 22:40 UTCMay 18, 23:10 UTC30m
2026-05-18 ABL788 CXR → ICN May 18, 08:25 UTCMay 18, 19:35 UTC11h 9m
2026-05-18 ABL157 FUK → ICN May 18, 06:01 UTCMay 18, 06:35 UTC35m
2026-05-18 ABL158 ICN → FUK May 18, 02:20 UTCMay 18, 02:45 UTC25m
2026-05-17 ABL7485 CNX → ICN May 17, 17:50 UTCMay 17, 22:45 UTC4h 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 HL8504 page for operator, model, and routing details .

Mode-S 71C504 frequently asked

What is Mode-S code 71C504?
71C504 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8504.
Where is Mode-S 71C504 registered?
Mode-S code 71C504 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 71C504 broadcasting right now?
No active broadcast right now. Last signal was 16h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C504, octal 34342404, decimal 7,456,004.
What flights does 71C504 operate?
Mode-S 71C504 has broadcast 12 distinct callsigns, including ABL173, ABL157, ABL156, ABL174, ABL158.