Apparatus

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sensors Mode-S transponder

71C354

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

Currently assigned to HL8354 · BOEING 737-800

Hex
71C354
Octal
34341524
Decimal
7,455,572
Country
KR
Tail
HL8354
Type
B738
No current signal · last broadcast Jul 26, 10:50 UTC
Flights observed
472
Distinct callsigns
20
Country
KR
Last broadcast
Jul 26, 10:50 UTC

Last known position

Most recent position reported by Mode-S 71C354.

Country allocation

The ICAO 24-bit address 71C354 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
TWB639 - 16 2026-07-02
TWB640 Tway Airlines 15 2026-07-02
TWB849 - 10 2026-07-11
TWB676 - 10 2026-06-26
TWB322 Tway Airlines 10 2026-07-25
TWB321 Tway Airlines 10 2026-07-25
TWB850 - 9 2026-07-11
TWB675 - 9 2026-06-26
TWB331 - 9 2026-07-12
TWB702 Tway Airlines 8 2026-07-22
TWB652 - 8 2026-07-17
TWB718 Tway Airlines 7 2026-07-22
TWB717 - 7 2026-07-12
TWB706 - 7 2026-07-24
TWB701 - 7 2026-07-01
TWB332 Tway Airlines 7 2026-07-26
TWB844 - 6 2026-07-11
TWB733 - 6 2026-07-23
TWB707 - 6 2026-07-02
TWB651 - 6 2026-07-17

Recent flights last 50

DateFlightRouteTakeoffLandingDuration
2026-07-26 TWB908 CJU → KWJ Jul 26, 10:40 UTCJul 26, 10:50 UTC10m
2026-07-26 TWB907 KWJ → CJU Jul 26, 08:10 UTCJul 26, 08:20 UTC10m
2026-07-26 TWB906 CJU → KWJ Jul 26, 07:00 UTCJul 26, 07:10 UTC10m
2026-07-26 TWB332 KIX → CJU Jul 26, 03:25 UTCJul 26, 04:25 UTC1h 0m
2026-07-26 TWB319 PUS → KIX Jul 26, 00:25 UTCJul 26, 01:25 UTC1h 0m
2026-07-25 TWB236 FUK → PUS Jul 25, 11:15 UTCJul 25, 12:00 UTC45m
2026-07-25 TWB235 PUS → FUK Jul 25, 09:25 UTCJul 25, 09:55 UTC30m
2026-07-25 TWB322 KIX → PUS Jul 25, 06:55 UTCJul 25, 08:15 UTC1h 20m
2026-07-25 TWB321 PUS → KIX Jul 25, 04:00 UTCJul 25, 05:15 UTC1h 15m
2026-07-25 TWB232 FUK → PUS Jul 25, 02:20 UTCJul 25, 02:45 UTC25m
2026-07-25 TWB231 PUS → FUK Jul 25, 00:15 UTCJul 25, 00:35 UTC20m
2026-07-24 TWB042 CXR → PUS Jul 24, 22:45 UTCJul 24, 23:10 UTC25m
2026-07-24 TWB041 PUS → CXR Jul 24, 14:00 UTCJul 24, 21:35 UTC7h 35m
2026-07-24 TWB041 PUS → CXR Jul 24, 12:25 UTCJul 24, 12:40 UTC15m
2026-07-24 TWB927 GMP → PUS Jul 24, 10:15 UTCJul 24, 10:55 UTC40m
2026-07-24 TWB668 TSA → GMP Jul 24, 07:35 UTCJul 24, 08:15 UTC40m
2026-07-24 TWB668 TSA → GMP Jul 24, 06:05 UTCJul 24, 06:25 UTC20m
2026-07-24 TWB667 GMP → TSA Jul 24, 04:20 UTCJul 24, 04:45 UTC25m
2026-07-24 TWB667 GMP → TSA Jul 24, 02:35 UTCJul 24, 03:05 UTC30m
2026-07-24 TWB706 - Jul 24, 00:10 UTCJul 24, 00:55 UTC45m
2026-07-23 TWB703 GMP → CJU Jul 23, 22:10 UTCJul 23, 22:40 UTC30m
2026-07-23 TWB734 - Jul 23, 11:55 UTCJul 23, 12:40 UTC45m
2026-07-23 TWB733 - Jul 23, 09:50 UTCJul 23, 10:30 UTC40m
2026-07-23 TWB924 PUS → GMP Jul 23, 04:05 UTCJul 23, 04:50 UTC45m
2026-07-23 TWB923 GMP → PUS Jul 23, 02:15 UTCJul 23, 03:05 UTC50m
2026-07-22 TWB702 CJU → GMP Jul 22, 23:15 UTCJul 22, 23:55 UTC40m
2026-07-22 TWB801 TAE → CJU Jul 22, 21:25 UTCJul 22, 21:40 UTC15m
2026-07-22 TWB812 - Jul 22, 12:50 UTCJul 22, 13:15 UTC25m
2026-07-22 TWB718 CJU → GMP Jul 22, 03:30 UTCJul 22, 04:10 UTC40m
2026-07-22 TWB809 TAE → CJU Jul 22, 01:35 UTCJul 22, 01:50 UTC15m
2026-07-22 TWB804 CJU → TAE Jul 22, 00:05 UTCJul 22, 00:25 UTC20m
2026-07-21 TWB743 GMP → CJU Jul 21, 09:20 UTCJul 21, 09:50 UTC30m
2026-07-20 TWB762 - Jul 20, 22:55 UTCJul 20, 23:35 UTC40m
2026-07-20 TWB650 - Jul 20, 18:35 UTCJul 20, 19:55 UTC1h 20m
2026-07-20 TWB649 CJU → MFM Jul 20, 10:50 UTCJul 20, 12:15 UTC1h 25m
2026-07-20 TWB725 - Jul 20, 07:40 UTCJul 20, 08:15 UTC35m
2026-07-20 TWB720 - Jul 20, 05:00 UTCJul 20, 05:40 UTC40m
2026-07-20 TWB228 FUK → CJU Jul 20, 01:40 UTCJul 20, 02:05 UTC25m
2026-07-19 TWB213 TAE → FUK Jul 19, 22:55 UTCJul 19, 23:15 UTC20m
2026-07-19 TWB038 - Jul 19, 11:45 UTCJul 19, 21:40 UTC9h 55m
2026-07-19 TWB683 - Jul 19, 02:05 UTCJul 19, 08:10 UTC6h 5m
2026-07-18 TWB106 - Jul 18, 22:00 UTCJul 19, 00:40 UTC2h 40m
2026-07-18 TWB106 - Jul 18, 19:40 UTCJul 18, 19:55 UTC15m
2026-07-18 TWB105 - Jul 18, 12:40 UTCJul 18, 15:15 UTC2h 35m
2026-07-18 TWB810 - Jul 18, 10:30 UTCJul 18, 11:00 UTC30m
2026-07-18 TWB727 - Jul 18, 08:20 UTCJul 18, 09:00 UTC40m
2026-07-18 TWB722 - Jul 18, 06:30 UTCJul 18, 07:15 UTC45m
2026-07-18 TWB332 - Jul 18, 03:15 UTCJul 18, 04:10 UTC55m
2026-07-18 TWB319 PUS → KIX Jul 18, 00:39 UTCJul 18, 01:45 UTC1h 5m
2026-07-17 TWB042 - Jul 17, 22:55 UTCJul 17, 23:20 UTC25m

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 HL8354 page for operator, model, and routing details .

Mode-S 71C354 frequently asked

What is Mode-S code 71C354?
71C354 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8354.
Where is Mode-S 71C354 registered?
Mode-S code 71C354 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 71C354 broadcasting right now?
No active broadcast right now. Last signal was Jul 26, 10:50 UTC.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C354, octal 34341524, decimal 7,455,572.
What flights does 71C354 operate?
Mode-S 71C354 has broadcast 20 distinct callsigns, including TWB639, TWB640, TWB849, TWB676, TWB322.