Apparatus

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sensors Mode-S transponder

71C254

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

Currently assigned to HL8254 · BOEING 777-200

Hex
71C254
Octal
34341124
Decimal
7,455,316
Country
KR
Tail
HL8254
Type
B772
No current signal · last broadcast Jul 26, 20:45 UTC
Flights observed
278
Distinct callsigns
20
Country
KR
Last broadcast
Jul 26, 20:45 UTC

Last known position

Most recent position reported by Mode-S 71C254.

Country allocation

The ICAO 24-bit address 71C254 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
AAR551 Asiana Airlines 31 2026-07-24
AAR232 - 29 2026-06-28
AAR552 Asiana Airlines 27 2026-07-24
AAR231 - 22 2026-06-29
AAR561 - 21 2026-06-30
AAR562 Asiana Airlines 20 2026-07-01
AAR271 - 15 2026-07-17
AAR601 - 12 2026-07-11
AAR272 - 12 2026-07-16
AAR602 - 11 2026-07-12
AAR704 Asiana Airlines 10 2026-07-25
AAR703 Asiana Airlines 10 2026-07-25
AAR730 - 8 2026-06-22
AAR546 - 6 2026-07-15
AAR545 - 6 2026-07-14
AAR729 - 5 2026-06-22
AAR334 Asiana Airlines 4 2026-06-03
AAR712 Asiana Airlines 3 2026-07-26
AAR711 Asiana Airlines 3 2026-07-26
AAR372 Asiana Airlines 3 2026-04-15

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 AAR734 HAN → ICN Jul 26, 19:50 UTCJul 26, 20:35 UTC45m
2026-07-26 AAR734 HAN → ICN Jul 26, 16:45 UTCJul 26, 16:55 UTC10m
2026-07-26 AAR733 ICN → HAN Jul 26, 10:55 UTCJul 26, 12:35 UTC1h 40m
2026-07-26 AAR712 TPE → ICN Jul 26, 04:35 UTCJul 26, 06:45 UTC2h 11m
2026-07-26 AAR711 ICN → TPE Jul 26, 00:00 UTCJul 26, 02:05 UTC2h 5m
2026-07-25 AAR704 MNL → ICN Jul 25, 16:35 UTCJul 25, 20:05 UTC3h 30m
2026-07-25 AAR703 ICN → MNL Jul 25, 10:45 UTCJul 25, 14:10 UTC3h 25m
2026-07-24 AAR552 IST → ICN Jul 24, 15:30 UTCJul 25, 00:40 UTC9h 10m
2026-07-24 AAR551 ICN → IST Jul 24, 13:15 UTCJul 24, 13:35 UTC20m
2026-07-24 AAR551 ICN → IST Jul 24, 03:55 UTCJul 24, 12:30 UTC8h 35m
2026-07-24 AAR551 ICN → IST Jul 24, 02:40 UTCJul 24, 03:00 UTC20m
2026-07-23 AAR552 IST → ICN Jul 23, 23:25 UTCJul 23, 23:55 UTC30m
2026-07-23 AAR552 IST → ICN Jul 23, 14:50 UTCJul 23, 22:45 UTC7h 55m
2026-07-23 AAR551 ICN → IST Jul 23, 03:10 UTCJul 23, 12:50 UTC9h 40m
2026-07-23 AAR551 ICN → IST Jul 23, 01:55 UTCJul 23, 02:20 UTC25m
2026-07-22 AAR360 HGH → ICN Jul 22, 11:10 UTCJul 22, 11:15 UTC5m
2026-07-21 AAR552 IST → ICN Jul 21, 23:55 UTCJul 22, 00:15 UTC20m
2026-07-21 AAR552 IST → ICN Jul 21, 15:10 UTCJul 21, 23:00 UTC7h 50m
2026-07-21 AAR551 ICN → IST Jul 21, 12:25 UTCJul 21, 12:50 UTC25m
2026-07-21 AAR551 ICN → IST Jul 21, 01:55 UTCJul 21, 11:50 UTC9h 55m
2026-07-20 AAR364 ICN → ICN Jul 20, 02:20 UTCJul 20, 07:10 UTC4h 50m
2026-07-19 AAR704 - Jul 19, 16:25 UTCJul 19, 19:45 UTC3h 20m
2026-07-19 AAR703 ICN → MNL Jul 19, 10:35 UTCJul 19, 14:05 UTC3h 30m
2026-07-19 AAR364 ICN → ICN Jul 19, 02:05 UTCJul 19, 06:55 UTC4h 50m
2026-07-18 AAR552 IST → ICN Jul 18, 16:35 UTCJul 18, 23:50 UTC7h 15m
2026-07-18 AAR552 IST → ICN Jul 18, 15:05 UTCJul 18, 15:30 UTC25m
2026-07-18 AAR551 - Jul 18, 12:35 UTCJul 18, 12:55 UTC20m
2026-07-18 AAR551 - Jul 18, 03:05 UTCJul 18, 11:55 UTC8h 50m
2026-07-18 AAR551 - Jul 18, 01:54 UTCJul 18, 02:14 UTC20m
2026-07-17 AAR271 SEA → ICN Jul 17, 07:44 UTCJul 17, 18:25 UTC10h 40m
2026-07-16 AAR272 ICN → SEA Jul 16, 12:49 UTCJul 16, 23:15 UTC10h 25m
2026-07-16 AAR360 - Jul 16, 09:20 UTCJul 16, 10:00 UTC40m
2026-07-16 AAR359 - Jul 16, 04:30 UTCJul 16, 05:10 UTC40m
2026-07-15 AAR704 - Jul 15, 16:15 UTCJul 15, 19:40 UTC3h 25m
2026-07-15 AAR703 - Jul 15, 10:55 UTCJul 15, 14:20 UTC3h 25m
2026-07-15 AAR546 - Jul 15, 03:25 UTCJul 15, 03:45 UTC20m
2026-07-14 AAR546 - Jul 14, 17:10 UTCJul 15, 02:40 UTC9h 29m
2026-07-14 AAR545 - Jul 14, 03:25 UTCJul 14, 14:45 UTC11h 20m
2026-07-14 AAR545 - Jul 14, 02:10 UTCJul 14, 02:25 UTC15m
2026-07-13 AAR712 TPE → ICN Jul 13, 04:50 UTCJul 13, 06:55 UTC2h 5m
2026-07-13 AAR711 ICN → TPE Jul 13, 00:05 UTCJul 13, 02:01 UTC1h 55m
2026-07-12 AAR602 SYD → ICN Jul 12, 11:30 UTCJul 12, 21:50 UTC10h 20m
2026-07-11 AAR601 - Jul 11, 23:25 UTCJul 12, 09:25 UTC10h 0m
2026-07-11 AAR271 SEA → ICN Jul 11, 07:25 UTCJul 11, 17:55 UTC10h 30m
2026-07-10 AAR272 ICN → SEA Jul 10, 13:05 UTCJul 10, 23:05 UTC10h 1m
2026-07-10 AAR546 - Jul 10, 03:15 UTCJul 10, 03:40 UTC25m
2026-07-09 AAR546 - Jul 9, 17:10 UTCJul 10, 02:15 UTC9h 5m
2026-07-09 AAR545 - Jul 9, 03:35 UTCJul 9, 15:00 UTC11h 25m
2026-07-09 AAR545 - Jul 9, 02:15 UTCJul 9, 02:30 UTC15m
2026-07-08 AAR602 SYD → ICN Jul 8, 11:30 UTCJul 8, 22:05 UTC10h 35m

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 HL8254 page for operator, model, and routing details .

Mode-S 71C254 frequently asked

What is Mode-S code 71C254?
71C254 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8254.
Where is Mode-S 71C254 registered?
Mode-S code 71C254 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 71C254 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 20:45 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C254, octal 34341124, decimal 7,455,316.
What flights does 71C254 operate?
Mode-S 71C254 has broadcast 20 distinct callsigns, including AAR551, AAR232, AAR552, AAR231, AAR561.