sensors Mode-S transponder

71C241

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

Currently assigned to HL8241 · BOEING 737-800

Hex
71C241
Octal
34341101
Decimal
7,455,297
Country
KR
Tail
HL8241
Type
B738
No current signal · last broadcast 20h ago
Flights observed
3
Distinct callsigns
3
Country
KR
Last broadcast
20h ago

Last known position

Most recent position reported by Mode-S 71C241.

Country allocation

The ICAO 24-bit address 71C241 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 3 distinct

Callsign Airline Flights Last seen
KAL156 - 1 2026-04-13
KAL155 Korean Air 1 2026-04-13
KAL1431 - 1 2026-04-14

Recent flights last 3

DateFlightRouteTakeoffLandingDuration
2026-04-14 KAL1431 - Apr 14, 10:25 UTCApr 14, 11:00 UTC35m
2026-04-13 KAL156 - Apr 13, 10:00 UTCApr 13, 10:35 UTC35m
2026-04-13 KAL155 ICN → HFE Apr 13, 05:00 UTCApr 13, 05:45 UTC45m

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 HL8241 page for operator, model, and routing details .

Mode-S 71C241 frequently asked

What is Mode-S code 71C241?
71C241 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8241.
Where is Mode-S 71C241 registered?
Mode-S code 71C241 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 71C241 broadcasting right now?
No active broadcast right now. Last signal was 20h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C241, octal 34341101, decimal 7,455,297.
What flights does 71C241 operate?
Mode-S 71C241 has broadcast 3 distinct callsigns, including KAL156, KAL155, KAL1431.