sensors Mode-S transponder

840CD8

ICAO 24-bit transponder address · allocated to Japan

Currently assigned to JA03JJ · AIRBUS A-320

Hex
840CD8
Octal
41006330
Decimal
8,654,040
Country
JP
Tail
JA03JJ
Type
A320
Broadcasting now · callsign JJP230 · 12,350 ft
Flights observed
8
Distinct callsigns
6
Country
JP
Last broadcast
12h ago

Current position

840CD8 is currently broadcasting. Map zoomed to live position.

Country allocation

The ICAO 24-bit address 840CD8 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 6 distinct

Callsign Airline Flights Last seen
JJP55 Jetstar Japan 3 2026-04-14
JJP54 Jetstar Japan 1 2026-04-14
JJP522 - 1 2026-04-13
JJP449 - 1 2026-04-13
JJP426 - 1 2026-04-13
JJP423 - 1 2026-04-13

Recent flights last 8

DateFlightRouteTakeoffLandingDuration
2026-04-14 JJP54 TPE → KIX Apr 14, 10:30 UTCApr 14, 10:55 UTC25m
2026-04-14 JJP55 KIX → TPE Apr 14, 09:10 UTCApr 14, 09:20 UTC10m
2026-04-14 JJP55 KIX → TPE Apr 14, 08:25 UTCApr 14, 09:05 UTC40m
2026-04-14 JJP55 KIX → TPE Apr 14, 06:50 UTCApr 14, 07:00 UTC10m
2026-04-13 JJP449 - Apr 13, 22:35 UTCApr 13, 23:35 UTC1h 0m
2026-04-13 JJP426 - Apr 13, 04:20 UTCApr 13, 07:20 UTC3h 0m
2026-04-13 JJP423 - Apr 13, 04:00 UTCApr 13, 04:15 UTC15m
2026-04-13 JJP522 - Apr 13, 01:10 UTCApr 13, 02:30 UTC1h 20m

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 JA03JJ page for operator, model, and routing details .

Mode-S 840CD8 frequently asked

What is Mode-S code 840CD8?
840CD8 is an ICAO 24-bit transponder address. Allocated to Japan. Assigned to JA03JJ.
Where is Mode-S 840CD8 registered?
Mode-S code 840CD8 is allocated to Japan (JP). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 840CD8 broadcasting right now?
Yes. Mode-S 840CD8 is currently airborne.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 840CD8, octal 41006330, decimal 8,654,040.
What flights does 840CD8 operate?
Mode-S 840CD8 has broadcast 6 distinct callsigns, including JJP55, JJP54, JJP522, JJP449, JJP426.