sensors Mode-S transponder

71C553

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

Currently assigned to HL8553 · BOEING 737 MAX 8

Hex
71C553
Octal
34342523
Decimal
7,456,083
Country
KR
Tail
HL8553
Type
B38M
Broadcasting now · callsign JJA1305 · 17,300 ft
Flights observed
11
Distinct callsigns
6
Country
KR
Last broadcast
16h ago

Current position

71C553 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 71C553 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 6 distinct

Callsign Airline Flights Last seen
JJA5304 Jeju Air 3 2026-04-13
JJA5303 - 2 2026-04-13
JJA1202 - 2 2026-04-13
JJA1201 - 2 2026-04-13
JJA2623 - 1 2026-04-14
JJA1306 - 1 2026-04-14

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 JJA2623 - Apr 14, 09:25 UTCApr 14, 10:00 UTC35m
2026-04-14 JJA1306 - Apr 14, 05:15 UTCApr 14, 06:05 UTC50m
2026-04-13 JJA5304 DPS → ICN Apr 13, 20:50 UTCApr 13, 21:35 UTC45m
2026-04-13 JJA5304 DPS → ICN Apr 13, 16:40 UTCApr 13, 19:40 UTC3h 0m
2026-04-13 JJA5303 - Apr 13, 08:20 UTCApr 13, 11:50 UTC3h 30m
2026-04-13 JJA5303 - Apr 13, 06:55 UTCApr 13, 08:15 UTC1h 20m
2026-04-13 JJA1202 - Apr 13, 04:20 UTCApr 13, 05:15 UTC55m
2026-04-13 JJA1202 - Apr 13, 03:50 UTCApr 13, 04:15 UTC25m
2026-04-13 JJA1201 - Apr 13, 01:50 UTCApr 13, 02:00 UTC10m
2026-04-13 JJA1201 - Apr 13, 00:50 UTCApr 13, 01:20 UTC30m
2026-04-12 JJA5304 DPS → ICN Apr 12, 17:15 UTCApr 12, 20:05 UTC2h 50m

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 HL8553 page for operator, model, and routing details .

Mode-S 71C553 frequently asked

What is Mode-S code 71C553?
71C553 is an ICAO 24-bit transponder address. Allocated to Korea, South. Assigned to HL8553.
Where is Mode-S 71C553 registered?
Mode-S code 71C553 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 71C553 broadcasting right now?
Yes. Mode-S 71C553 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 71C553, octal 34342523, decimal 7,456,083.
What flights does 71C553 operate?
Mode-S 71C553 has broadcast 6 distinct callsigns, including JJA5304, JJA5303, JJA1202, JJA1201, JJA2623.