sensors Mode-S transponder

840659

ICAO 24-bit transponder address · allocated to Japan

Currently assigned to JA01RK · BOEING 737-800

Hex
840659
Octal
41003131
Decimal
8,652,377
Country
JP
Tail
JA01RK
Type
B738
No current signal · last broadcast 14h ago
Flights observed
13
Distinct callsigns
6
Country
JP
Last broadcast
14h ago

Last known position

Most recent position reported by Mode-S 840659.

Country allocation

The ICAO 24-bit address 840659 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
JAL934 - 5 2026-04-14
JAL192 - 2 2026-04-13
JAL191 - 2 2026-04-14
JAL184 - 2 2026-04-13
JAL933 - 1 2026-04-13
JAL183 Japan Airlines 1 2026-04-13

Recent flights last 13

DateFlightRouteTakeoffLandingDuration
2026-04-14 JAL191 - Apr 14, 09:55 UTCApr 14, 10:20 UTC25m
2026-04-14 JAL934 - Apr 14, 07:35 UTCApr 14, 08:25 UTC50m
2026-04-14 JAL934 - Apr 14, 06:15 UTCApr 14, 06:35 UTC20m
2026-04-13 JAL183 HND → KMQ Apr 13, 22:25 UTCApr 13, 22:50 UTC25m
2026-04-13 JAL192 - Apr 13, 11:55 UTCApr 13, 12:20 UTC25m
2026-04-13 JAL192 - Apr 13, 11:40 UTCApr 13, 12:15 UTC35m
2026-04-13 JAL191 - Apr 13, 10:00 UTCApr 13, 10:25 UTC25m
2026-04-13 JAL934 - Apr 13, 08:20 UTCApr 13, 08:40 UTC20m
2026-04-13 JAL934 - Apr 13, 07:55 UTCApr 13, 08:40 UTC45m
2026-04-13 JAL934 - Apr 13, 04:20 UTCApr 13, 08:15 UTC3h 55m
2026-04-13 JAL933 - Apr 13, 02:15 UTCApr 13, 02:50 UTC35m
2026-04-13 JAL184 - Apr 13, 00:20 UTCApr 13, 00:40 UTC20m
2026-04-13 JAL184 - Apr 13, 00:00 UTCApr 13, 00:40 UTC40m

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 JA01RK page for operator, model, and routing details .

Mode-S 840659 frequently asked

What is Mode-S code 840659?
840659 is an ICAO 24-bit transponder address. Allocated to Japan. Assigned to JA01RK.
Where is Mode-S 840659 registered?
Mode-S code 840659 is allocated to Japan (JP). All aircraft registered there receive a Mode-S address from a fixed block defined by ICAO Annex 10.
Is 840659 broadcasting right now?
No active broadcast right now. Last signal was 14h ago.
Hex, octal, and decimal Mode-S codes: what's the difference?
The same 24-bit identifier expressed in different bases: hex 840659, octal 41003131, decimal 8,652,377.
What flights does 840659 operate?
Mode-S 840659 has broadcast 6 distinct callsigns, including JAL934, JAL192, JAL191, JAL184, JAL933.