Apparatus

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sensors Mode-S transponder

71C321

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

Currently assigned to HL8321 · BOEING 737-800

Hex
71C321
Octal
34341441
Decimal
7,455,521
Country
KR
Tail
HL8321
Type
B738
No current signal · last broadcast 1h ago
Flights observed
264
Distinct callsigns
20
Country
KR
Last broadcast
1h ago

Last known position

Most recent position reported by Mode-S 71C321.

Country allocation

The ICAO 24-bit address 71C321 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
JJA131 Jeju Air 8 2026-05-28
JJA226 Jeju Air 7 2026-05-26
JJA136 Jeju Air 7 2026-05-26
JJA122 Jeju Air 7 2026-05-29
JJA117 Jeju Air 7 2026-05-29
JJA115 Jeju Air 7 2026-05-30
JJA108 Jeju Air 7 2026-05-29
JJA225 Jeju Air 6 2026-05-26
JJA127 Jeju Air 6 2026-05-26
JJA120 Jeju Air 6 2026-05-28
JJA212 Jeju Air 5 2026-05-25
JJA211 Jeju Air 5 2026-05-26
JJA158 Jeju Air 5 2026-05-10
JJA157 Jeju Air 5 2026-05-10
JJA156 Jeju Air 5 2026-05-10
JJA155 Jeju Air 5 2026-05-10
JJA116 Jeju Air 5 2026-05-26
JJA101 Jeju Air 5 2026-05-25
JJA151 Jeju Air 4 2026-05-05
JJA142 Jeju Air 4 2026-05-15

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-05-30 JJA115 GMP → CJU May 30, 03:00 UTCMay 30, 03:25 UTC25m
2026-05-29 JJA122 CJU → GMP May 29, 05:25 UTCMay 29, 06:00 UTC35m
2026-05-29 JJA117 GMP → CJU May 29, 03:15 UTCMay 29, 03:40 UTC25m
2026-05-29 JJA108 CJU → GMP May 29, 01:40 UTCMay 29, 02:15 UTC35m
2026-05-28 JJA711 TAE → CJU May 28, 23:25 UTCMay 28, 23:35 UTC10m
2026-05-28 JJA131 GMP → CJU May 28, 07:10 UTCMay 28, 07:35 UTC25m
2026-05-28 JJA120 CJU → GMP May 28, 05:30 UTCMay 28, 06:05 UTC35m
2026-05-28 JJA115 GMP → CJU May 28, 03:00 UTCMay 28, 03:25 UTC25m
2026-05-27 JJA118 CJU → GMP May 27, 04:24 UTCMay 27, 04:59 UTC35m
2026-05-27 JJA113 GMP → CJU May 27, 02:14 UTCMay 27, 02:39 UTC25m
2026-05-27 JJA104 CJU → GMP May 27, 00:34 UTCMay 27, 01:09 UTC35m
2026-05-26 JJA105 GMP → CJU May 26, 22:05 UTCMay 26, 22:29 UTC25m
2026-05-26 JJA136 CJU → GMP May 26, 12:35 UTCMay 26, 13:10 UTC35m
2026-05-26 JJA225 CJJ → CJU May 26, 10:14 UTCMay 26, 10:29 UTC15m
2026-05-26 JJA226 CJU → CJJ May 26, 08:50 UTCMay 26, 09:15 UTC25m
2026-05-26 JJA127 GMP → CJU May 26, 06:20 UTCMay 26, 06:49 UTC30m
2026-05-26 JJA116 CJU → GMP May 26, 03:35 UTCMay 26, 04:10 UTC35m
2026-05-26 JJA211 PUS → GMP May 26, 01:30 UTCMay 26, 01:44 UTC15m
2026-05-25 JJA212 CJU → CJJ May 25, 23:49 UTCMay 26, 00:14 UTC25m
2026-05-25 JJA101 GMP → CJU May 25, 21:30 UTCMay 25, 21:54 UTC25m
2026-05-25 JJA140 CJU → GMP May 25, 12:45 UTCMay 25, 13:15 UTC30m
2026-05-25 JJA137 GMP → CJU May 25, 10:25 UTCMay 25, 10:50 UTC25m
2026-05-25 JJA124 CJU → GMP May 25, 06:35 UTCMay 25, 07:05 UTC30m
2026-05-25 JJA121 GMP → CJU May 25, 04:25 UTCMay 25, 04:50 UTC25m
2026-05-25 JJA112 CJU → GMP May 25, 03:00 UTCMay 25, 03:35 UTC35m
2026-05-24 JJA102 CJU → GMP May 24, 23:00 UTCMay 24, 23:25 UTC25m
2026-05-24 JJA141 GMP → CJU May 24, 11:35 UTCMay 24, 12:00 UTC25m
2026-05-24 JJA132 CJU → GMP May 24, 10:10 UTCMay 24, 10:35 UTC25m
2026-05-24 JJA133 GMP → CJU May 24, 07:55 UTCMay 24, 08:20 UTC25m
2026-05-24 JJA122 CJU → GMP May 24, 05:30 UTCMay 24, 06:00 UTC30m
2026-05-24 JJA117 GMP → CJU May 24, 03:10 UTCMay 24, 03:35 UTC25m
2026-05-24 JJA108 CJU → GMP May 24, 01:45 UTCMay 24, 02:15 UTC30m
2026-05-23 JJA706 CJU → TAE May 23, 09:45 UTCMay 23, 09:55 UTC10m
2026-05-23 JJA131 GMP → CJU May 23, 07:15 UTCMay 23, 07:40 UTC25m
2026-05-23 JJA120 CJU → GMP May 23, 05:00 UTCMay 23, 05:35 UTC35m
2026-05-23 JJA115 GMP → CJU May 23, 02:45 UTCMay 23, 03:10 UTC25m
2026-05-22 JJA130 CJU → GMP May 22, 09:35 UTCMay 22, 10:15 UTC40m
2026-05-22 JJA702 CJU → TAE May 22, 06:15 UTCMay 22, 06:30 UTC15m
2026-05-22 JJA119 GMP → CJU May 22, 03:40 UTCMay 22, 04:05 UTC25m
2026-05-22 JJA106 CJU → GMP May 22, 01:45 UTCMay 22, 02:20 UTC35m
2026-05-21 JJA5257 PUS → UBN May 21, 12:50 UTCMay 21, 20:30 UTC7h 40m
2026-05-21 JJA1354 KIX → PUS May 21, 10:20 UTCMay 21, 10:55 UTC35m
2026-05-21 JJA1353 PUS → KIX May 21, 04:05 UTCMay 21, 08:35 UTC4h 30m
2026-05-20 JJA2552 BKK → PUS May 20, 18:15 UTCMay 21, 02:30 UTC8h 15m
2026-05-20 JJA2551 PUS → BKK May 20, 13:10 UTCMay 20, 16:45 UTC3h 35m
2026-05-20 JJA1352 KIX → PUS May 20, 01:45 UTCMay 20, 02:20 UTC35m
2026-05-19 JJA1351 PUS → KIX May 19, 23:35 UTCMay 20, 00:15 UTC40m
2026-05-18 JJA1354 KIX → PUS May 18, 10:25 UTCMay 18, 10:55 UTC30m
2026-05-18 JJA1353 PUS → KIX May 18, 08:15 UTCMay 18, 09:15 UTC1h 0m
2026-05-18 JJA6152 TPE → PUS May 18, 05:00 UTCMay 18, 05:20 UTC20m

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 HL8321 page for operator, model, and routing details .

Mode-S 71C321 frequently asked

What is Mode-S code 71C321?
71C321 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8321.
Where is Mode-S 71C321 registered?
Mode-S code 71C321 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 71C321 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 71C321, octal 34341441, decimal 7,455,521.
What flights does 71C321 operate?
Mode-S 71C321 has broadcast 20 distinct callsigns, including JJA131, JJA226, JJA136, JJA122, JJA117.