sensors Mode-S transponder

8515C4

ICAO 24-bit transponder address · allocated to Japan

Currently assigned to JA329J · BOEING 737-800

Hex
8515C4
Octal
41212704
Decimal
8,721,860
Country
JP
Tail
JA329J
Type
B738
Transponder active on ground
Flights observed
11
Distinct callsigns
9
Country
JP
Last broadcast
12h ago

Last known position

Most recent position reported by Mode-S 8515C4.

Country allocation

The ICAO 24-bit address 8515C4 falls within the block assigned to Japan (JP) by ICAO Annex 10, Volume III. Every aircraft registered in Japan 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 9 distinct

Callsign Airline Flights Last seen
JAL2009 - 2 2026-04-14
JAL151 - 2 2026-04-13
JAL575 - 1 2026-04-13
JAL572 - 1 2026-04-13
JAL462 - 1 2026-04-13
JAL461 - 1 2026-04-13
JAL454 - 1 2026-04-13
JAL2506 - 1 2026-04-14
JAL140 Japan Airlines 1 2026-04-13

Recent flights last 11

DateFlightRouteTakeoffLandingDuration
2026-04-14 JAL2506 - Apr 14, 09:10 UTCApr 14, 10:55 UTC1h 45m
2026-04-14 JAL2009 - Apr 14, 07:10 UTCApr 14, 07:55 UTC45m
2026-04-14 JAL2009 - Apr 14, 06:30 UTCApr 14, 07:10 UTC40m
2026-04-13 JAL140 AOJ → HND Apr 13, 22:45 UTCApr 13, 23:40 UTC55m
2026-04-13 JAL151 - Apr 13, 11:55 UTCApr 13, 12:20 UTC25m
2026-04-13 JAL151 - Apr 13, 11:25 UTCApr 13, 12:15 UTC50m
2026-04-13 JAL462 - Apr 13, 09:20 UTCApr 13, 10:05 UTC45m
2026-04-13 JAL461 - Apr 13, 07:05 UTCApr 13, 07:45 UTC40m
2026-04-13 JAL572 - Apr 13, 05:20 UTCApr 13, 06:00 UTC40m
2026-04-13 JAL575 - Apr 13, 02:20 UTCApr 13, 02:45 UTC25m
2026-04-13 JAL454 - Apr 13, 00:25 UTCApr 13, 01:00 UTC35m

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 JA329J page for operator, model, and routing details .

Mode-S 8515C4 frequently asked

What is Mode-S code 8515C4?
8515C4 is an ICAO 24-bit transponder address. Allocated to Japan. Assigned to JA329J.
Where is Mode-S 8515C4 registered?
Mode-S code 8515C4 is allocated to Japan (JP). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 8515C4 broadcasting right now?
Mode-S 8515C4 is currently broadcasting from the ground.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 8515C4, octal 41212704, decimal 8,721,860.
What flights does 8515C4 operate?
Mode-S 8515C4 has broadcast 9 distinct callsigns, including JAL2009, JAL151, JAL575, JAL572, JAL462.