sensors Mode-S transponder

71BF18

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

Currently assigned to HL7718 · BOEING 737-900

Hex
71BF18
Octal
34337430
Decimal
7,454,488
Country
KR
Tail
HL7718
Type
B739
No current signal · last broadcast 1d ago
Flights observed
8
Distinct callsigns
7
Country
KR
Last broadcast
1d ago

Last known position

Most recent position reported by Mode-S 71BF18.

Country allocation

The ICAO 24-bit address 71BF18 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
JNA406 - 2 2026-04-13
JNA764 - 1 2026-04-13
JNA763 - 1 2026-04-13
JNA507 - 1 2026-04-13
JNA504 - 1 2026-04-12
JNA430 - 1 2026-04-13
JNA405 - 1 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-13 JNA764 - Apr 13, 19:55 UTCApr 13, 20:15 UTC20m
2026-04-13 JNA763 - Apr 13, 14:50 UTCApr 13, 15:10 UTC20m
2026-04-13 JNA430 - Apr 13, 08:05 UTCApr 13, 08:15 UTC10m
2026-04-13 JNA405 - Apr 13, 05:45 UTCApr 13, 06:15 UTC30m
2026-04-13 JNA406 - Apr 13, 04:20 UTCApr 13, 04:35 UTC15m
2026-04-13 JNA406 - Apr 13, 04:05 UTCApr 13, 04:15 UTC10m
2026-04-13 JNA507 - Apr 13, 01:50 UTCApr 13, 02:25 UTC35m
2026-04-12 JNA504 - Apr 12, 23:55 UTCApr 13, 00:25 UTC30m

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 HL7718 page for operator, model, and routing details .

Mode-S 71BF18 frequently asked

What is Mode-S code 71BF18?
71BF18 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL7718.
Where is Mode-S 71BF18 registered?
Mode-S code 71BF18 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 71BF18 broadcasting right now?
No active broadcast right now. Last signal was 1d ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71BF18, octal 34337430, decimal 7,454,488.
What flights does 71BF18 operate?
Mode-S 71BF18 has broadcast 7 distinct callsigns, including JNA406, JNA764, JNA763, JNA507, JNA504.