Apparatus

Try JFK, AAL1290, BAW, or N225AN.

sensors Mode-S transponder

71C251

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

Currently assigned to HL8251 · BOEING 777-200LR

Hex
71C251
Octal
34341121
Decimal
7,455,313
Country
KR
Tail
HL8251
Type
B77L
No current signal · last broadcast 1h ago
Flights observed
239
Distinct callsigns
20
Country
KR
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S 71C251.

Country allocation

The ICAO 24-bit address 71C251 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
KAL504 Korean Air 14 2026-04-26
KAL313 - 11 2026-06-17
KAL274 - 11 2026-07-13
KAL9575 Korean Air 9 2026-05-27
KAL273 - 9 2026-07-12
KAL251 - 9 2026-06-19
KAL503 Korean Air 8 2026-04-25
KAL278 Korean Air 8 2026-07-09
KAL277 - 8 2026-07-09
KAL282 - 7 2026-04-14
KAL9576 Korean Air 6 2026-05-28
KAL542 - 6 2026-07-07
KAL541 - 6 2026-07-07
KAL349 - 6 2026-05-09
KAL314 Korean Air 6 2026-06-17
KAL249 - 6 2026-06-15
KAL281 - 5 2026-04-13
KAL9210 Korean Air 4 2026-07-05
KAL8231 - 4 2026-06-29
KAL231 Korean Air 4 2026-05-28

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-13 KAL274 - Jul 13, 22:45 UTCJul 14, 10:15 UTC11h 30m
2026-07-13 KAL274 - Jul 13, 12:25 UTCJul 13, 19:45 UTC7h 20m
2026-07-13 KAL274 - Jul 13, 06:50 UTCJul 13, 07:01 UTC10m
2026-07-12 KAL274 - Jul 12, 23:50 UTCJul 13, 02:40 UTC2h 50m
2026-07-12 KAL273 - Jul 12, 14:05 UTCJul 12, 21:40 UTC7h 35m
2026-07-12 KAL273 - Jul 12, 04:25 UTCJul 12, 11:50 UTC7h 25m
2026-07-11 KAL273 - Jul 11, 19:15 UTCJul 12, 03:05 UTC7h 50m
2026-07-11 KAL8204 - Jul 11, 03:15 UTCJul 11, 15:15 UTC12h 0m
2026-07-10 KAL8203 - Jul 10, 13:35 UTCJul 11, 00:25 UTC10h 51m
2026-07-09 KAL278 YVR → ICN Jul 9, 21:25 UTCJul 10, 08:10 UTC10h 45m
2026-07-09 KAL278 YVR → ICN Jul 9, 10:05 UTCJul 9, 18:40 UTC8h 35m
2026-07-09 KAL277 ANC → DFW Jul 9, 02:10 UTCJul 9, 07:45 UTC5h 35m
2026-07-08 KAL277 ICN → ANC Jul 8, 17:10 UTCJul 9, 01:00 UTC7h 50m
2026-07-08 KAL8314 HKG → ICN Jul 8, 09:35 UTCJul 8, 12:40 UTC3h 5m
2026-07-08 KAL8313 - Jul 8, 04:05 UTCJul 8, 07:15 UTC3h 10m
2026-07-07 KAL542 - Jul 7, 21:55 UTCJul 7, 22:15 UTC20m
2026-07-07 KAL542 - Jul 7, 10:55 UTCJul 7, 21:10 UTC10h 15m
2026-07-07 KAL541 VIE → OSL Jul 7, 07:15 UTCJul 7, 09:10 UTC1h 55m
2026-07-06 KAL541 ICN → VIE Jul 6, 17:05 UTCJul 7, 04:45 UTC11h 40m
2026-07-05 KAL9210 LAX → SEA Jul 5, 20:45 UTCJul 6, 07:50 UTC11h 5m
2026-07-05 KAL9210 LAX → SEA Jul 5, 17:00 UTCJul 5, 19:00 UTC2h 0m
2026-07-05 KAL9209 ICN → LAX Jul 5, 03:15 UTCJul 5, 14:15 UTC11h 0m
2026-07-04 KAL322 - Jul 4, 23:20 UTCJul 5, 00:10 UTC50m
2026-07-04 KAL321 - Jul 4, 15:55 UTCJul 4, 16:35 UTC40m
2026-07-03 KAL274 - Jul 3, 22:45 UTCJul 4, 11:25 UTC12h 40m
2026-07-03 KAL274 - Jul 3, 06:45 UTCJul 3, 20:40 UTC13h 55m
2026-07-03 KAL274 - Jul 3, 00:00 UTCJul 3, 02:50 UTC2h 50m
2026-07-02 KAL273 MIA → VCP Jul 2, 14:00 UTCJul 2, 21:45 UTC7h 45m
2026-07-02 KAL273 MIA → VCP Jul 2, 03:45 UTCJul 2, 11:10 UTC7h 25m
2026-07-01 KAL273 MIA → VCP Jul 1, 19:15 UTCJul 2, 02:35 UTC7h 20m
2026-07-01 KAL8314 HKG → ICN Jul 1, 09:05 UTCJul 1, 12:05 UTC3h 0m
2026-07-01 KAL8313 - Jul 1, 06:55 UTCJul 1, 07:05 UTC10m
2026-07-01 KAL8313 - Jul 1, 04:05 UTCJul 1, 06:20 UTC2h 15m
2026-06-30 KAL8232 - Jun 30, 03:50 UTCJun 30, 17:25 UTC13h 35m
2026-06-29 KAL8231 - Jun 29, 19:39 UTCJun 30, 01:30 UTC5h 51m
2026-06-29 KAL8231 - Jun 29, 10:50 UTCJun 29, 18:25 UTC7h 35m
2026-06-29 KAL568 - Jun 29, 06:44 UTCJun 29, 07:09 UTC25m
2026-06-28 KAL568 - Jun 28, 20:09 UTCJun 29, 05:59 UTC9h 50m
2026-06-28 KAL567 VIE → ZRH Jun 28, 17:10 UTCJun 28, 18:10 UTC1h 0m
2026-06-28 KAL567 ICN → VIE Jun 28, 01:04 UTCJun 28, 13:14 UTC12h 10m
2026-06-27 KAL8204 - Jun 27, 02:55 UTCJun 27, 15:34 UTC12h 40m
2026-06-26 KAL8203 - Jun 26, 13:30 UTCJun 26, 23:44 UTC10h 15m
2026-06-26 KAL390 - Jun 26, 00:39 UTCJun 26, 09:14 UTC8h 35m
2026-06-25 KAL389 - Jun 25, 16:14 UTCJun 25, 21:55 UTC5h 40m
2026-06-25 KAL8258 ANC → ICN Jun 25, 03:44 UTCJun 25, 11:54 UTC8h 10m
2026-06-24 KAL8258 - Jun 24, 19:34 UTCJun 25, 02:19 UTC6h 45m
2026-06-24 KAL8258 - Jun 24, 16:54 UTCJun 24, 18:05 UTC1h 10m
2026-06-24 KAL8257 ANC → JFK Jun 24, 08:09 UTCJun 24, 14:45 UTC6h 35m
2026-06-23 KAL8257 ICN → ANC Jun 23, 22:55 UTCJun 24, 06:50 UTC7h 55m
2026-06-22 KAL274 - Jun 22, 22:40 UTCJun 23, 10:59 UTC12h 20m

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 HL8251 page for operator, model, and routing details .

Mode-S 71C251 frequently asked

What is Mode-S code 71C251?
71C251 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8251.
Where is Mode-S 71C251 registered?
Mode-S code 71C251 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 71C251 broadcasting right now?
No active broadcast right now. Last signal was 1h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C251, octal 34341121, decimal 7,455,313.
What flights does 71C251 operate?
Mode-S 71C251 has broadcast 20 distinct callsigns, including KAL504, KAL313, KAL274, KAL9575, KAL273.