sensors Mode-S transponder

71C374

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

Currently assigned to HL8374 · BOEING 737-800

Hex
71C374
Octal
34341564
Decimal
7,455,604
Country
KR
Tail
HL8374
Type
B738
No current signal · last broadcast 17h ago
Flights observed
9
Distinct callsigns
7
Country
KR
Last broadcast
17h ago

Last known position

Most recent position reported by Mode-S 71C374.

Country allocation

The ICAO 24-bit address 71C374 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 7 distinct

Callsign Airline Flights Last seen
ESR987 - 2 2026-04-13
ESR952 - 2 2026-04-14
ESR988 - 1 2026-04-13
ESR982 Eastar Jet 1 2026-04-12
ESR951 - 1 2026-04-14
ESR916 - 1 2026-04-13
ESR915 - 1 2026-04-13

Recent flights last 9

DateFlightRouteTakeoffLandingDuration
2026-04-14 ESR952 - Apr 14, 09:10 UTCApr 14, 10:30 UTC1h 20m
2026-04-14 ESR952 - Apr 14, 08:50 UTCApr 14, 09:05 UTC15m
2026-04-14 ESR951 - Apr 14, 05:45 UTCApr 14, 07:10 UTC1h 25m
2026-04-13 ESR988 - Apr 13, 18:50 UTCApr 13, 19:10 UTC20m
2026-04-13 ESR987 - Apr 13, 15:30 UTCApr 13, 15:50 UTC20m
2026-04-13 ESR987 - Apr 13, 14:05 UTCApr 13, 14:15 UTC10m
2026-04-13 ESR916 - Apr 13, 07:30 UTCApr 13, 07:50 UTC20m
2026-04-13 ESR915 - Apr 13, 05:00 UTCApr 13, 05:15 UTC15m
2026-04-12 ESR982 PQC → PUS Apr 12, 18:50 UTCApr 12, 19:55 UTC1h 5m

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 HL8374 page for operator, model, and routing details .

Mode-S 71C374 frequently asked

What is Mode-S code 71C374?
71C374 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8374.
Where is Mode-S 71C374 registered?
Mode-S code 71C374 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 71C374 broadcasting right now?
No active broadcast right now. Last signal was 17h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C374, octal 34341564, decimal 7,455,604.
What flights does 71C374 operate?
Mode-S 71C374 has broadcast 7 distinct callsigns, including ESR987, ESR952, ESR988, ESR982, ESR951.