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
Transponder active on ground
Flights observed
614
Distinct callsigns
20
Country
KR
Last broadcast
Jul 26, 21:20 UTC

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
JJA226 - 13 2026-07-16
JJA136 - 13 2026-07-16
JJA225 - 12 2026-07-16
JJA127 - 12 2026-07-16
JJA120 - 12 2026-07-05
JJA115 - 12 2026-07-05
JJA131 - 11 2026-06-20
JJA129 - 10 2026-07-06
JJA122 - 10 2026-07-06
JJA117 - 10 2026-07-06
JJA108 - 10 2026-07-06
JJA128 - 9 2026-07-06
JJA123 Jeju Air 9 2026-07-22
JJA106 - 9 2026-07-05
JJA212 - 8 2026-07-10
JJA211 - 8 2026-07-11
JJA158 - 8 2026-07-11
JJA157 - 8 2026-07-11
JJA156 - 8 2026-07-11
JJA155 - 8 2026-07-11

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 JJA5258 UBN → PUS Jul 26, 12:45 UTCJul 26, 21:10 UTC8h 25m
2026-07-26 JJA1552 CTS → PUS Jul 26, 05:40 UTCJul 26, 07:45 UTC2h 6m
2026-07-26 JJA1551 PUS → CTS Jul 26, 02:00 UTCJul 26, 04:05 UTC2h 5m
2026-07-26 JJA1452 FUK → PUS Jul 26, 00:05 UTCJul 26, 00:35 UTC30m
2026-07-25 JJA1451 PUS → FUK Jul 25, 22:10 UTCJul 25, 22:35 UTC25m
2026-07-25 JJA8852 SJW → PUS Jul 25, 06:30 UTCJul 25, 07:20 UTC50m
2026-07-25 JJA8852 SJW → PUS Jul 25, 05:25 UTCJul 25, 05:40 UTC15m
2026-07-25 JJA8851 PUS → SJW Jul 25, 02:50 UTCJul 25, 03:10 UTC20m
2026-07-25 JJA8851 PUS → SJW Jul 25, 01:05 UTCJul 25, 01:55 UTC50m
2026-07-24 JJA502 CJU → PUS Jul 24, 23:20 UTCJul 24, 23:40 UTC20m
2026-07-24 JJA8134 - Jul 24, 19:05 UTCJul 24, 20:30 UTC1h 25m
2026-07-24 JJA8133 - Jul 24, 14:20 UTCJul 24, 14:50 UTC30m
2026-07-24 JJA141 GMP → CJU Jul 24, 11:50 UTCJul 24, 12:25 UTC35m
2026-07-24 JJA132 CJU → GMP Jul 24, 10:10 UTCJul 24, 10:55 UTC45m
2026-07-24 JJA133 GMP → CJU Jul 24, 08:10 UTCJul 24, 08:45 UTC35m
2026-07-24 JJA124 CJU → GMP Jul 24, 06:35 UTCJul 24, 07:15 UTC40m
2026-07-24 JJA121 GMP → CJU Jul 24, 04:30 UTCJul 24, 05:05 UTC35m
2026-07-24 JJA112 CJU → GMP Jul 24, 02:50 UTCJul 24, 03:30 UTC40m
2026-07-24 JJA111 GMP → CJU Jul 24, 00:35 UTCJul 24, 01:10 UTC35m
2026-07-23 JJA102 CJU → GMP Jul 23, 22:35 UTCJul 23, 23:20 UTC45m
2026-07-23 JJA141 - Jul 23, 12:05 UTCJul 23, 12:45 UTC40m
2026-07-23 JJA132 CJU → GMP Jul 23, 10:25 UTCJul 23, 11:10 UTC45m
2026-07-23 JJA133 GMP → CJU Jul 23, 08:20 UTCJul 23, 08:55 UTC35m
2026-07-23 JJA124 CJU → GMP Jul 23, 06:35 UTCJul 23, 07:15 UTC40m
2026-07-23 JJA121 GMP → CJU Jul 23, 04:30 UTCJul 23, 05:05 UTC35m
2026-07-23 JJA112 CJU → GMP Jul 23, 02:40 UTCJul 23, 03:25 UTC45m
2026-07-23 JJA111 GMP → CJU Jul 23, 00:35 UTCJul 23, 01:10 UTC35m
2026-07-22 JJA904 PUS → GMP Jul 22, 22:25 UTCJul 22, 23:05 UTC40m
2026-07-22 JJA5257 PUS → UBN Jul 22, 12:45 UTCJul 22, 21:05 UTC8h 20m
2026-07-22 JJA123 GMP → CJU Jul 22, 04:40 UTCJul 22, 05:15 UTC35m
2026-07-22 JJA114 CJU → GMP Jul 22, 02:40 UTCJul 22, 03:20 UTC40m
2026-07-22 JJA301 KWJ → CJU Jul 22, 00:55 UTCJul 22, 01:05 UTC10m
2026-07-21 JJA302 CJU → KWJ Jul 21, 23:50 UTCJul 22, 00:00 UTC10m
2026-07-21 JJA103 GMP → CJU Jul 21, 21:45 UTCJul 21, 22:20 UTC35m
2026-07-21 JJA140 CJU → GMP Jul 21, 12:50 UTCJul 21, 13:30 UTC40m
2026-07-21 JJA137 GMP → CJU Jul 21, 10:40 UTCJul 21, 11:15 UTC35m
2026-07-21 JJA6124 KHH → GMP Jul 21, 05:10 UTCJul 21, 07:40 UTC2h 30m
2026-07-21 JJA6123 GMP → KHH Jul 21, 00:55 UTCJul 21, 03:25 UTC2h 30m
2026-07-20 JJA904 PUS → GMP Jul 20, 22:20 UTCJul 20, 23:00 UTC40m
2026-07-20 JJA514 CJU → PUS Jul 20, 11:25 UTCJul 20, 11:50 UTC25m
2026-07-20 JJA305 - Jul 20, 09:30 UTCJul 20, 09:45 UTC15m
2026-07-20 JJA306 CJU → KWJ Jul 20, 08:20 UTCJul 20, 08:30 UTC10m
2026-07-20 JJA507 PUS → CJU Jul 20, 06:15 UTCJul 20, 06:35 UTC20m
2026-07-20 JJA506 CJU → PUS Jul 20, 04:50 UTCJul 20, 05:10 UTC20m
2026-07-20 JJA213 - Jul 20, 02:50 UTCJul 20, 03:20 UTC30m
2026-07-20 JJA214 - Jul 20, 01:00 UTCJul 20, 01:30 UTC30m
2026-07-19 JJA107 - Jul 19, 22:55 UTCJul 19, 23:35 UTC40m
2026-07-19 JJA186 CJU → GMP Jul 19, 10:35 UTCJul 19, 11:10 UTC35m
2026-07-19 JJA8136 - Jul 19, 03:25 UTCJul 19, 08:15 UTC4h 50m
2026-07-19 JJA109 - Jul 19, 00:05 UTCJul 19, 00:40 UTC35m

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?
Mode-S 71C321 is currently broadcasting from the ground.
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 JJA226, JJA136, JJA225, JJA127, JJA120.